Research ArticleSorption of Uranium Ions from Their Aqueous Solution byResins Containing Nanomagnetite Particles
Mahmoud O Abd El-Magied
Nuclear Materials Authority PO Box 530 El Maadi Cairo Egypt
Correspondence should be addressed to Mahmoud O Abd El-Magied mahmoud nmayahoocom
Received 15 November 2015 Accepted 26 January 2016
Academic Editor Dmitry Murzin
Copyright copy 2016 Mahmoud O Abd El-MagiedThis is an open access article distributed under theCreativeCommonsAttributionLicense which permits unrestricted use distribution and reproduction in anymedium provided the originalwork is properly cited
Magnetic amine resins composed of nanomagnetite (Fe3O4) core and glycidyl methacrylate (GMA)NN1015840-methylenebisacrylamide
(MBA) shell were prepared by suspension polymerization of glycidyl methacrylate with NN1015840-methylenebisacrylamide in thepresence of nanomagnetite particles and immobilized with different amine ligands These resins showed good magnetic propertiesand could be easily retrieved from their suspensions using an external magnetic field Adsorption behaviors of uranium ions onthe prepared resins were studied Maximum sorption capacities of uranium ions on R-1 and R-2 were found to be 92 and 158mggUranium was extracted successfully from three granite samples collected from Gabal Gattar pluton North Eastern Desert EgyptThe studied resins showed good durability and regeneration using HNO
3
1 Introduction
Recently synthesis properties and application of magneticpolymer beads in solving many environmental problemshave received considerable attentionThemagnetoresponsivepolymeric beads benefit comes from the combination oftheir components features magnetic particles and polymer[1 2] Magnetic chelating resins are conveniently used totreat industrial wastewater and recovermetal ions where theyare easily collected and rapidly precipitated in a magneticfield that improves the operative technology of recovery andseparationMagnetic chelating resins are prepared by coatingmagnetic nano- or microiron particles or another ferromag-neticmaterial with either an organic polymer or ion exchangeresin by adsorption or by direct bonding the size of beads canvary from hundred nanometers to few millimeters [3ndash6]
Synthesis of magnetic polymer beads can be achievedin three ways (1) the magnetic particles are synthesizedinside polymer matrix (2) the polymer is synthesized in thepresence ofmagnetic particles and (3) the beads are preparedfrom preformed polymer and magnetic particles [6ndash10]Magnetic core-polymer shell beads are usually prepared bythree-dimensional polymerization ofmonomer togetherwithcross-linker on the surface of magnetic particles Nano- and
micromagnetic particles are of great interest for many tech-nological applications like separation of metal ions medicalapplications and oil industry [3ndash10]
Fe3O4-glycidyl methacrylateiminodiacetic acidstyrene
divinylbenzene resin was prepared and used in removal ofCu+2 Cd+2 and Pb+2 from aqueous solutions The equi-librium adsorption capacities of the resin were 088 081and 078mmolg for Cu+2 Pb+2 and Cd+2 respectively[3] Magnetic poly(GMA) microspheres were prepared bypolymerization of GMA in the presence of polyethyleneglycol-coated magnetite nanoparticles The microsphereswere hydrolyzed and carboxyl groups introduced by oxi-dation with KMnO
4[4] A magnetic chelating resin was
obtained from polymerization of glycidyl methacrylate inthe presence of divinylbenzene as a cross-linker and finelydivided magnetic particles of Co
3O4 The embedded metal
oxide particles impart magnetic properties to the resin inaddition to increasing the chelating active sites on the surfaceThe obtained resin was modified with amine functionalityand evaluated towards the uptake of Hg+2 Cu+2 and Ni+2from their aqueous solutions [5] GMAMBA resinsmodifiedby embedded iron oxide (Fe
2O3) were prepared Amino and
thiol functionalities were immobilized on the obtained resins
Hindawi Publishing CorporationJournal of EngineeringVolume 2016 Article ID 7214348 11 pageshttpdxdoiorg10115520167214348
2 Journal of Engineering
for Ag adsorption [6] Glycidylmethacrylate resins were pre-pared in the presence and absence of iron oxide (Fe
2O3) The
conducted resins were subsequently treated with ethylenedi-amine giving the corresponding amine-chelating resins Theuptake behavior of both resins towards Cu+2 ions in aqueoussolutions using batch and column techniques was studied[7] Magnetic chitosan resin was chemically modified by apolymeric Schiff rsquos base cross-linker and used for mercury+2uptake with capacity value of 28mmolg [8] Schiff rsquos basechitosan composites with magnetic properties were preparedthrough the reaction between chitosan and polymeric Schiffbase of thioureaglutaraldehyde in the presence of magnetiteThe sorption characteristics of this composite towards U(VI)at different experimental conditions were carried out bymeans of batch and column methods where it showedsorption capacity reached 232mmolg [9]
The main target of this paper was to increase the con-centration of active sites available for interaction with themetal ionsThe target was approached through spreading theresin as a film over iron oxide particles and using a cross-linker with hydrophilic characters The other target of thispaperwas to increase the chemical andmechanical stability ofmodified glycidyl methacrylate resins with amine moiety toenhance their adsorption capacities towards U(VI) ions fromthe aqueous solutions The target was approached throughincreasing degree of cross-linking as well as modifying allparameters that affect the polymerization process such asthe continuous phase initiator diluents and polymerizationtemperature In the present work GMAMBA was preparedby suspension polymerization ofGMAwithMBA in the pres-ence of nanomagnetite particles Different amine moietieswere immobilized on the magnetic GMAMBA copolymersThe obtained magnetic resins were applied for separationof U(VI) ions from aqueous solutions The different factorsaffecting the separation process such as initial concentra-tion of the metal ion pH shaking time and temperaturewere studied Kinetic and thermodynamic parameters of theadsorption process were calculated
2 Materials and Methods
All the chemicals were of analytical grade ofMerck or Sigma-Aldrich trademark and were used as received without furtherpurification All of the solutions were prepared with freshdouble distilled water A uranium stock solution containing1000mg Lminus1 of U(VI) was prepared by dissolving 1782 g ofuranyl acetate in 1 nitric acid and diluting to 1000mL usingthe double distilled water
The U(VI) measurement was estimated spectrophoto-metrically using Arsenazo I method [11] by the PC scan-ning spectrophotometer UVVIS double beam of the typeLabomed Inc (USA)
Nanomagnetite was prepared following the modifiedMassart method [10] 100mL (02M) of Fe+3 solutions wasadded with stirring to freshly prepared 100mL (01M) ofFe+2 solutions Then 100mL of ammonia solution (30)was suddenly poured to the previously prepared Fe+3Fe+2solutions with vigorous stirring A black precipitate wasformed and was allowed to crystallize for 30min with
stirringThe precipitate was washed with deoxygenated water(water was boiled to repeal any gases and then bubbledwith nitrogen gas) under magnetic decantation until pH ofsuspension became below 75 The precipitate was dried atroom temperature to give a black powder
Magnetic GMAMBA was prepared through suspen-sion copolymerization of GMA in the presence of cross-linking agent (MBA) nanomagnetite (F
3O4) and 22-
azobis(isobutyronitrile) (AIBN) as an initiator following thepreviously reported method [10] The contents were refluxedon a water bath at 80∘C with continuous stirring for 8 h Aheavy precipitate was formed filtered off washed with waterand ethanol to remove the diluents and then dried
Two portions of the magnetic GMAMBA copolymerswere weighted 2 g each One of them was added portionwiseto the stirred solution of 10mL ethylenediamine (DA) whilethe second portion was added to diethylenetriamine (TA) inproper flasksThemixtures were placed in an oil bath at 80∘Cfor 72 h with stirring speed of 300 rpm After completionof the reaction the formed beads were simply decanted andwashed several times and then dried The obtained resinswere marked as R-1 and R-2 respectively
Adsorption experiments under controlled pH were car-ried out by adding portions of 005 g resin in a series offlasks each one containing 100mL solution of (100mg Lminus1)U(VI) ions solution The pH was adapted in the range of1ndash5 using nitric acid or sodium hydroxide solutions Theflasks were shaken on a shaking water bath model 1083(Labortechnik GmbH Germany) at 300 rpm for 2 h at 25∘CAfter equilibration the residual concentration of the metalion was determined
To conduct the time effect 005 g of R-1 or R-2 wasput in a series of flasks containing 100mL of U(VI) ionssolution (100mg Lminus1) at pH 5 The flasks were shaken ona shaking water bath for the required time period Theeffect of initial concentration of U(VI) ion was carried outat definite concentrations (20ndash120mg Lminus1) and pH 5 Thecontents of the flasks were equilibrated on a shaking waterbath while keeping the temperature at 25 30 40 and 50∘CAfter adsorption the residual U(VI) concentration of themetal ion was determined
The effect of the solidliquid ratio on the adsorptionefficiency of the studied resins was achieved by varying theamount of beads from 0025 to 0125 g in the adsorptionmedium (100mL containing 100mg Lminus1 U(VI)) while keep-ing other parameters (pH contact time and temperature)constant according to their values obtained from the previousexperiments
3 Results and Discussions
Scheme 1 shows the preparation of the magnetic GMAMBAresins and their chemical modification with DA or TAthrough epoxide ring to give R-1 and R-2 respectively asshown in Scheme 1
The structural characteristics of the resins obtained wereverified using FT-IR measurements The spectra of resinsshowed the stretching band of oxirane group of magneticGMAMBA at 910 cmminus1 disappeared in the spectra of resins
Journal of Engineering 3
CC
OC
HC
C
O
O
CH
CNH
CNH
C
O
CC
OC
HC
C
C
O
O
CH
O
GMA MBA
Magnetic GMAMBA
HC
HC
O
Magnetic GMAMBA
OEmbedded magnetite
Polymeric film
R
C
HO HN
HC
HOHN
R
NH
NH
HN
R
HC
CNH
CNH
CCH
C
O O
R
DA or TA
R
R
R
H2C
H2C
CH3
CH3
H2
H2
H2H2H2H2
H2
H2
CH2
CH2
CH2
CH2
CH2
CH2
R1 = H or CH2CH2NH2
+
R = resin matrix
R1
R1NH2
R-1 or R-2
+
Scheme 1 Chemical preparation of resins containing nanomagnetite
R-1 and R-2 Moreover the spectra of R-1 and R-2 are char-acterized by ]NH
2at 3443 cmminus1 This indicates the success of
modification process Energy dispersive X-raymeasurements(EDX) of R-1 and R-2 showed that the resin contains a weightpercentage of 10 of Fe
3O4 The resin particles of magnetite
R-1 and R-2 were characterized by dynamic light scattering(DLS) The average sizes of magnetite particles were 18ndash92 nm while the average sizes of R-1 and R-2 particles were615 nmndash4801 nm
The chemical stability of R-1 and R-2 in acid and alkalinemedia was tested by shaking a 05 g portion of the resinsin turn with 100mL of 1M HCl and 1M NaOH for 24 hThe resins were then filtered off and washed with water Theadsorption capacities after the treatments were reduced byonly 5ndash7 which were denoted as desirable stability of theresin No obvious leakage of resins and change of resins wereobserved in the experimental process
31 Effect of pH Sorption of U(VI) from aqueous solutionsby R-1 and R-2 was determined under noncompetitive con-ditions at different pH values as shown in Figure 1 The
0
60
120
180
0 1 2 3 4 5 6pH
qe
(mg
g)
R-1R-2
Figure 1 Effect of pH on adsorption process
sorption of uranium was found to be increased as thesolution pH increased The maximum sorption capacitieswere observed at pH 5 for R-1 and R-2 As indicated in Table 1
4 Journal of Engineering
Figure 2 The scanning electron microscopy images of the studied resins before and after uranium sorption
Table 1 Adsorption capacities of uranium by different adsorbents
Chelating resins 119902119890(mgg) Reference
Modified polystyrene 595 [18]Calix[4]resorcinarene 640 [19]Tetramethylmalonamide (TMMA) 1190 [20]Amberlite XAD-4-succinic acid 123 [21]Modified Dowextrade 12K 498 [22]Nanoporous silica 294 [23]Mesoporous carbon CMK-5 652 [24]4-Vinylpyridine 134 [25]Salicylaldoxime and 4-vinylpyridine 12 [26]IRA-402 resin 213 [27]Covalent organic frameworks 81 [28]Salicylaldoxime and 4-vinylpyridine 115 [29]R-1 92 This workR-2 158 This work
the investigated resins were characterized by higher 119902119890value
relative to that reported by othersThe surface morphology of the studied resins before
and after uranium sorption was studied by SEM analysis(Figure 2) The surface morphology of the uranium loadedresins showed a large particle with close-packed plane
surface which could be assigned to the sorption of uraniumions onto the surface of the studied loaded resins
The observed lower sorption of U(VI) ions in higheracidic medium may be attributed to the partial protonationof the amino groups to give positively charged protonatedamino groups that do not promote U(VI) adsorption due torepulsion force
Hydrolysis of U(VI) ions was observed to begin at pH gt 5and various positively charged hydrolyzed uranium speciesexist ([(UO
2)3(OH)4]2+ [(UO
2)2OH]3+ [(UO
2)3(OH)]5+
and [(UO2)4(OH)]7+) which have lower affinity to R-1 and R-
2 Also negatively charged uranium species ([UO2(OH)4]2minus
and [(UO2)3(OH)7]minus) were found at higher pH values which
cannot react with R-1 and R-2 [10ndash12]The values of the experimentalmaximum sorption capac-
ities were 92 and 158mgg for R-1 and R-2 The values of themaximum sorption of resins are related to their amine groupcontent of 55 and 81mmolg for R-1 and R-2 The higherconcentration of amine active sites in case of R-1 and R-2relative to the free magnetite ones (38 and 54mmolg) mayindicate the formation of extended thin film of the resin overthe metal oxide particles This would allow the active siteshidden within the core of the resin matrix to become moreexposed for interaction with metal ions [10]
The mechanism of interaction between U(VI) ions andamine active sites on R-1 and R-2 resins may be relatedto their coordination modes U(VI) ions can coordinate by
Journal of Engineering 5
0
60
120
180
0 30 60 90Time (min)
qt
(mg
g)
R-1R-2
Figure 3 Effect of time on adsorption process
four five or six amine active sites of R-1 and R-2 resins[10] The molar ratios of sorbed U(VI) ions and resins activesites are 1 4 1 5 and 1 6 The experimental maximumsorption capacities of 92mgg (039mmolg) and 158mgg(066mmolg) for R-1 and R-2 are closer to the theoreticalsorption value corresponding to the molar ratio of 1 6 (092and 14mmolg for R-1 and R-2) The observed differencesbetween the experimental and expected sorption capacitiesvalues may be attributed to the nonaccessibility of all activesites for coordination with U(VI)This behavior confirms theeffect of textural properties on the nature of binding as wellas the sorption capacity
32 Effect of Contact Time and Adsorption Kinetics Sorptionof U(VI) on both R-1 and R-2 resins was investigated as afunction of contact time and the data obtained are shownin Figure 3 Uranium sorption increased as the contact timeincreased and reached its maximum sorption capacities at45 and 30min on R-1 and R-2 respectively To verify theorder of the adsorption process pseudo-first-order kineticsand pseudo-second-order kineticsmodels [10 12] were testedaccording to the following equations
Pseudo first order log (119902119890minus 119902119905) = log (119902
1st) minus1198961
2303119905
Pseudo second order 119905119902119905
=1
119896211990222nd+1
119902119890
119905
(1)
where 119902119890is the maximum experimental sorption capacity
(mg gminus1) 119902119905is the experimental sorption capacity at time (119905)
(mg gminus1) 1199021st is the calculated sorption capacity according
to pseudo-first-order model (mg gminus1) 1198961is the rate constant
of pseudo-first-order (minminus1) 1199022nd is the calculated sorption
capacity according to pseudo-second-order model (mg gminus1)and 119896
2is the rate constant of pseudo-second-order (minminus1)
Values of 1198961and 119902
1st were calculated from the slope andintercept values of plotting log(119902
119890minus 119902119905) versus (119905) as shown in
Figure 4 The plot of 119905119902119905versus (119905) (Figure 5) gives a straight
line with slope and intercept equal to 1119902119890and 1119896
2119902119890
2
05
1
15
2
0 10 20 30 40Time (min)
R-1R-2
log(qeminusqt)
Figure 4 The pseudo-first-order kinetics model
0
02
04
06
0 20 40 60Time (min)
tqt
R-1R-2
Figure 5 The pseudo-second-order kinetics model
respectivelyThe calculated values of 1198961 1199021st 1198962 and 1199022nd were
reported in Table 2The obtained data (119902 and 1198772) proved that the adsorption
rate is likely to be controlled by pseudo-second-order kineticmodel rather than the pseudo-first-order kinetic modelThe rate of adsorption is less controlled by intraparticlediffusion due to the bulky size of U(VI) ions that implies thatadsorption of U(VI) is dependent on concentration of boththe metal ions and active sites concentrations
33 Effect of Adsorption Temperature The temperature effecton U(VI) adsorption was tested as function of 4 temperaturedegrees (298 303 313 and 323) (Figure 6) An increase intemperature resulting in an increase in the amount of U(VI)adsorbed per unit mass of all resins might be attributed tothe change in surface properties of the sorbent and solubilityof the solute species with endothermic nature of the sorptionprocess
34 Adsorption Isotherms A relation between the amount ofadsorbate adsorbed on a given surface at constant temper-ature and the equilibrium concentration of the substrate in
6 Journal of Engineering
Table 2 Kinetic data for adsorption of U(VI) on R-1 and R-2 resins
Resin Experimental Pseudo-first-order kinetics Pseudo-second-order kinetics119902119890(mgg) 119902
1st (mgg) 1198961(minminus1) 119877
21199022nd (mgg) 119896
2(minminus1) 119877
2
R-1 92 5117 006 0942 100 0003 0997R-2 158 7413 007 0935 200 0002 0993
0
40
80
120
0 30 60 90
R-1
0
60
120
180
0 15 30 45
R-2
Ce (mgL)
qe
(mg
g)
Ce (mgL)
qe
(mg
g)298K303K
313K323K
298K303K
313K323K
Figure 6 Effect of adsorption temperature on adsorption process
0
03
06
09
0 20 40 60
R-1
0
005
01
015
0 10 20 30
R-2
Ce (mgL) Ce (mgL)
Ceq
e(g
L)
Ceq
e(g
L)
298K303K
313K323K
298K303K
313K323K
Figure 7 Langmuir adsorption isotherm
contact with the adsorbent is known as adsorption isothermAdsorption isotherms depend on certain parameters whosevalues express the surface properties and the affinity of thesorbent We can compute experimental results from equilib-rium experiences by several adsorption isotherm models
(1) Langmuir Model The most widely used isotherm equa-tion for modeling equilibrium data is the Langmuir modelLangmuir derived a relation between adsorbed material andits equilibrium concentration [10 13 14] The linear form ofLangmuir equation is given by
119862119890
119902119890
=119862119890
119902max+
1
119870119871119876max
(2)
where 119862119890is the equilibrium concentration of ions in solution
(mg Lminus1) 119902119890is the amount adsorbed at 119862
119890(mg gminus1) 119876max
is the maximum adsorption capacity (mg gminus1) and 119870119871is
the binding constant which is related to the energy ofadsorption (Lmgminus1) Plotting 119862
119890119902119890against 119862
119890(Figure 7)
gives a straight line with slope and intercept equal to 1119876maxand 1119870
119871119876max respectively The values of 119870
119871and 119876max at
different temperatures are reported in Table 3 The values of119870119871and119876max increase as the temperature increases Increasing
of119870119871value with increasing of temperature implies the strong
binding between U(VI) ions and the active sites at elevatedtemperatures
The thermodynamic parameters such as enthalpy change(Δ119867∘) and entropy change (Δ119878∘) corresponding to U(IV)sorption on the studied resins were calculated using VanrsquotHoff equation [10]
ln119870119871=Δ119878∘
119877minusΔ119867∘
119877119879 (3)
where 119877 is the universal gas constant (8314 Jmolminus1sdotKminus1)and 119879 is the absolute temperature (Kelvin) Plotting ln 119870
119871
against 1119879 (Figure 8) gives a straight line with interceptand slope equal to Δ119878∘119877 and minusΔ119867∘119877 respectively Thevalues of Δ119878∘ and Δ119867∘ were calculated and reported in
Journal of Engineering 7
Table 3 Isotherms parameters for the sorption of U(VI) ions
Resin Experimental 119902119890(mgg) Langmuir parameters Freundlich parameters
119870119871(Lmol) 119876Max (mgg) 119877
2119899 119870
119891(mgg) 119877
2
R-1 92 0026 100 0981 1247 3083 09907R-2 158 0133 16667 0977 1887 26485 08233
Resin Temkin parameters D-R parameters119861 (Jmol) 119860
119879(Lg) 119877
2119902119904(mgg) 119870ad (mol2kJ2) 119864 (kJmol2) 119877
2
R-1 5414 0080 0871 9454 9 times 10minus5 7454 085R-2 5127 0681 0934 1697 5 times 10minus5 100 0923
Table 4 Thermodynamic parameters for adsorption of U(VI) by R-1 and R-2 at different temperatures
Resin Temp (Kelvin) Thermodynamic parametersΔ119867∘ (kJmol) Δ119878
∘ (KJmolsdotK) 119879Δ119878∘ (kJmol) Δ119866
∘ (kJmol)
R-1
298
27328 016445
4901 minus2168303 4983 minus225313 5147 minus2414323 5312 minus2579
R-2
298
26064 01741
5188 minus2582303 5275 minus2669313 5449 minus2843323 5623 minus3017
Table 4 The positive Δ119867∘ value indicates that the adsorptionprocess is endothermic The positive value of Δ119878∘ maybe explained by the increased degree of randomness atthe resinsolution interface during the progress of sorptionprocess This phenomenon could be ascribed to liberation offree water molecules as a result of the substitution reactionbetween chelating amine active sites and hydrated U(VI)ion The Gibbs free energy of adsorption reaction (Δ119866∘) wascalculated using the following relation [10]
Δ119866∘= Δ119867
∘minus 119879Δ119878
∘ (4)
The values of Δ119866∘ values (Table 4) confirm the spon-taneous nature and feasibility of the sorption process andthe favorable U(VI) sorption takes place with increasing oftemperature
The suitability of the resins towards metal ions is throughthe values of separation factor constant (119877
119871) where 119877
119871gt 1
(unsuitable) 119877119871= 1 (linear) 0 lt 119877
119871lt 1 (suitable) 119877
119871= 0
(irreversible) [10] The value of 119877119871could be calculated from
(4)
119877119871=
1
1 + 119870119871119862119900
(5)
where 119862119900is the initial concentration of U(VI) ions (mM)
The values of 119877119871for sorption of U(VI) on R-1 and R-2
resins at different temperature were calculated and foundto lie between 0041 and 0281 indicating their suitability asadsorbents for U(VI)
(2) Freundlich Model The Freundlich isotherm model [1516] is an empirical relationship that describes the sorptionof solutes on a solid surface assuming that different sites
8
9
10
11
12
00031 00033 00035
1T (Kminus1)
ln K
L
R-1R-2
Figure 8 Vanrsquot Hoff plots for the adsorption process
with several sorption energies are involved (the surface ofadsorbent is heterogeneous)This isothermmodel is given by(3)
log 119902119890= log119870
119865+log119862119890
119899 (6)
where 119902119890(mg gminus1) and 119862
119890(mg Lminus1) are the equilibrium
concentrations of U(VI) in the solid and liquid phaserespectively 119870
119865(mg gminus1) and n are characteristic constants
related to the relative sorption capacity of the sorbent and theintensity of sorption respectively The higher the 1119899 valueis the more favorable the adsorption is generally 119899 lt 1 1119899and log119870
119865are the slope and intercept respectively given by
8 Journal of Engineering
0
05
1
15
2
25
0 05 1 15 2
log q
e
log Ce
R-1R-2
Figure 9 Freundlich adsorption isotherms
plotting log 119902119890against log119862
119890 The Freundlich plot (Figure 9)
gave a slope less than unity indicating the nonlinear sorptionbehavior with U(VI) in the concentration range studiedThe observed values of 119870
119865of R-1 and R-2 were found
to be 305 and 2649 (mg gminus1) The values of equilibriumsorption capacity and correlation coefficients of Langmuirequation (119876max) are more consistent with the experimentaldata than Freundlich isothermmodelTherefore the sorptionreaction is more favorable by Langmuir model confirmingthe monolayer coverage of uranium onto the amine resins
(3) Temkinrsquos Model The derivation of the Temkin isothermassumes that the fall in the heat of sorption is linear ratherthan logarithmic as implied in the Freundlich equation [1516] The linear form of Temkin isotherm is given by thefollowing equation
119902119890=119877119879
119887ln119860119879+119877119879
119887ln119862119890
119861 =119877119879
119887
119902119890= 119861 ln119860
119879+ 119861 ln119862
119890
(7)
where 119860119879is Temkin isotherm equilibrium binding constant
(Lg) 119887 is Temkin isotherm constant 119877 is universal gasconstant (8314 JmolK) 119879 is temperature at 298K and 119861is constant related to heat of sorption (Jmol) where 119902
119890
(mg gminus1) and 119862119890(mg Lminus1) are the equilibrium concentrations
of U(VI) in the solid and liquid phase respectively Plotting119902119890versus ln119862
119890(Figure 10) should give a straight line if the
adsorption energy decreases linearly with increasing surfacecoverage According to the given relation of 119902
119890versus ln119862
119890
the estimated 119861 values of R-1 and R-2 were 5127ndash5414 Jmolthat indicate the favorability of the chemical adsorptionprocess
341 Dubinin-Radushkevich Isotherm Model The Dubinin-Radushkevich (D-R) isotherm model is more general thanthe Langmuir isotherm as its deviation is not based on ideal
0
60
120
180
0 1 2 3 4 5
qe
ln Ce
R-1R-2
Figure 10 Temkin adsorption isotherms
assumptions such as equipotential of sorption sites absenceof steric hindrances between sorbed and incoming particlesand surface homogeneity onmicroscopic levelThis isothermmodel is a temperature-dependentmodel used to estimate thecharacteristic porosity in addition to the apparent energy ofadsorption as well as expressing the adsorption mechanism[15 17] The model is represented by the following equations
119902119890= (119902119904) exp(minus119870ad (119877119879 ln [1 +
1
119862119890
])
2
)
120576 = 119877119879 ln [1 + 1
119862119890
]
119902119890= (119902119904) exp (minus119870ad120576
2)
(8)
where 119902119890is the amount of adsorbate in the adsorbent at
equilibrium (mgg) 119902119904is the theoretical isotherm saturation
capacity (mgg)119870ad is the D-R isotherm constant (mol2kJ2)related to free energy of sorption 120576 is the D-R isothermconstant 119877 represents the gas constant (8314 Jmol K) 119879 isabsolute temperature (K) and 119862
119890is adsorbate equilibrium
concentration (mgL) The linearity of D-R isotherm modelis represented by the following equation
ln 119902119890= ln 119902
119904minus 119870ad120576
2 (9)
A plot of ln 119902119890versus 1205762 yielded straight lines indicating a
good fit of the isotherm to the experimental data (Figure 11)and the values of 119902
119904and119870ad for D-R isothermwere calculated
(Table 3) 119902119904and 1198772 values were observed that this isotherm
also gave very good description of the sorption process Thehigh values of 119902
119904show high sorption capacity The approach
was usually applied to distinguish the physical and chemicaladsorption of metal ions with its mean free energy permolecule of adsorbate The apparent energy (119864 = KJmol2) ofadsorption can be computed calculated using the followingrelation
119864 = [1
radic2119870ad] (10)
Journal of Engineering 9
3
4
5
6
0 20000 40000 60000
R-1R-2
ln q e
1205762
Figure 11 Dubinin-Radushkevich isotherm model
0
25
50
75
100
0
50
100
150
200
250
0 05 1 15
Adso
rptio
n ca
paci
ty (m
gg)
Solidliquid (mgmL)
Adso
rptio
n effi
cien
cy (
)
R-1 (mgg)R-2 (mgg)R-1 ()R-2 ()
Figure 12 The effect of the solidliquid ratio on the adsorptionefficiency
The values of the apparent energy of adsorption alsodepict chemisorption process
35 SolidLiquid Ratio The effect of the solidliquid ratio onthe adsorption efficiency of the studied resins was achievedusing variable amounts of R-1 and R-2 resins (0025 to 0125 g)in 100mL of the adsorption medium and the results wereshowed in Figure 12 The adsorption efficiency of the resinsincreased with increasing their dose while the adsorptioncapacities decreased This result is reasonable if we considerthat as the higher resin dose in the solution as the higheravailability of active sites for metal ion adsorption
36 Resin Regeneration For desorption studies 05 g of theuranium loaded dry resin with uranium was gently washedwith distilled water to remove any unabsorbed metal ionsand then shaken with 100mL of 01M HNO
3for 30min
and finally the uranium concentration was determined in thefiltrate All the experiments were performed in duplicate withexperimental error plusmn05ndash2 After the uranium elution theresins were regenerated by washing with 1M NaOH solutionfollowed by washing with distilled water hence the resinbecame regenerated and ready for the next use Regenerationefficiency was found to be about 90ndash96 for two resins over3 cycles
It is worth mentioning that using of the eluted resinswithout alkalinewashing failed to adsorbmore uranium ionswhich can be ascribed to the protonation of the amino activegroups that prevent the U(VI) ions adsorption Accordinglytreatment with the alkaline solution converted these proto-nated groups into free ones which have the affinity towardsthe U(VI) ions
37 Application of the Studied Resins for Granite SamplesThree granite rock samples were collected from Gabal Gattarpluton located inNorth EasternDesert of EgyptThe sampleswere crushed and ground to minus200 mesh size and analyzed byconventional wet chemical techniques for their major oxidecompositions as well as by XRF for some trace elements Thechemical analysis of the studied granitic samples is given inTable 5 The granitic samples contain high concentration ofFe2O3(t) Rb Y Nb U and Th and low concentration of Sr
and Ba compared with similar Egyptian granitesFor thework purpose the uranium content in the granitic
samples was selectively leached using nitric acid solution(2M) for 6 hours at 60∘C The reacted slurry was filteredand washed with hot water The obtained filtrate was treatedwith R-1 and R-2 for the uranium separation The uptakeresults of U(VI) ions (Table 6) showed that both the resinsdisplayed higher removal efficiency towards U(VI) relative toother metal ions present in sample solution
4 Conclusion
Magnetic glycidyl methacrylate resin particles with nano-magnetite core and glycidyl methacrylateNN1015840-methylene-bis-acrylamide resin shell were prepared and modified withDA and TA The studied resins showed high adsorptioncapacities towards uranium ions reached 92 and 158mggfor R-1 and R-2 respectively The results revealed that thepseudo-second-order sorption is the predominant mech-anism The amount of U(VI) adsorbed per unit mass ofall resins increased as temperature increased showing theendothermic nature of the sorption process The experimen-tal results from equilibrium experiences were computed byseveral adsorption isotherm models Langmuir FreundlichTemkin and Dubinin-Radushkevich isotherm model Theresults showed that the sorption reaction is more favorableby Langmuir model confirming the monolayer coverage ofuraniumonto the amine resins and indicate the favorability ofthe chemical adsorption processThe positive heat of adsorp-tion indicates that the adsorption process is endothermicThe
10 Journal of Engineering
Table 5 Chemical analysis of granitic samples
Sample Majorconstituent Trace
constituentConcentration
ppm
1
SiO2
735 U 4000AL2O3
128 Th 300Fe2O3
25 Rare earth 270CaO 13 Rb 225Na2O 26 Zr 197
MgO 05 Y 126K2O 24
2
SiO2
735 U 3200AL2O3
138 Th 190Fe2O3
36 Rare earth 270CaO 14 Rb mdashNa2O 06 Zr 400
MgO 05 Y 197K2O 24
3
SiO2
725 U 2700AL2O3
128 Th 260Fe2O3
25 Rare earth 250CaO 13 Rb 437Na2O 39 Zr 284
MgO 05 Y 135K2O 34
Table 6 Results of treatment of the granite samples with the studiedresins
Resin Metal ion Removal efficiency ()Sample 1 Sample 2 Sample 3
R-1U(VI) 93 93 928Fe(III) 26 25 26RE2O3
15 15 15
R-2U(VI) 995 992 99Fe(III) 31 31 31RE2O3
55 80 85
positive value of Δ119878∘ points to increasing of the randomnessdegree at the resinsolution interface during the progress ofsorption process The negative values of Δ119866∘ values confirmthe spontaneous nature of the sorption process
Finally it can be concluded that
(1) the prepared magnetite-cored resins have advantagetoward the filtration process where the magnetiteparticles impart the magnetic properties to the beadsthat allow rapid and easy separation of beads by theapplication of an external magnetic field avoidingsome technical problems arising due to using thetraditional filter papers
(2) the magnetite core allows more spreading of theactive group on the surface of resin particles thatenhance the adsorption efficiency comparing to othernonmagnetite core resins [10]
(3) the prepared resins are recommended as effectiveadsorbate materials regarding separation of uraniumions from their bearing solutions particularly in thepresence of other competitive metal ions
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] O Philippova A Barabanova V Molchanov and A KhokhlovldquoMagnetic polymer beads recent trends and developments insynthetic design and applicationsrdquo European Polymer Journalvol 47 no 4 pp 542ndash559 2011
[2] Q Yuan and R A Williams ldquoLarge scale manufacture ofmagnetic polymer particles using membranes and microfluidicdevicesrdquo China Particuology vol 5 no 1-2 pp 26ndash42 2007
[3] C-Y Chen C-L Chiang and P-C Huang ldquoAdsorptions ofheavy metal ions by a magnetic chelating resin containinghydroxy and iminodiacetate groupsrdquo Separation and Purifica-tion Technology vol 50 no 1 pp 15ndash21 2006
[4] D Horak B Rittich and A Spanova ldquoCarboxyl-functionalizedmagnetic microparticle carrier for isolation and identificationof DNA in dairy productsrdquo Journal of Magnetism and MagneticMaterials vol 311 no 1 pp 249ndash254 2007
[5] AAAtia AMDonia andA E Shahin ldquoStudies on the uptakebehavior of a magnetic Co
3O4-containing resin for Ni(II)
Cu(II) andHg(II) from their aqueous solutionsrdquo Separation andPurification Technology vol 46 no 3 pp 208ndash213 2005
[6] A M Donia A A Atia H A El-Boraey and D H MabroukldquoAdsorption of Ag(I) on glycidyl methacrylateNN1015840-methylenebis-acrylamide chelating resins with embedded iron oxiderdquoSeparation and Purification Technology vol 48 no 3 pp 281ndash287 2006
[7] A M Donia A A Atia H A El-Boraey and D H MabroukldquoUptake studies of copper(II) on glycidyl methacrylate chelat-ing resin containing Fe
2O3particlesrdquo Separation and Purifica-
tion Technology vol 49 no 1 pp 64ndash70 2006[8] A M Donia A A Atia and K Z Elwakeel ldquoSelective sepa-
ration of mercury(II) using magnetic chitosan resin modifiedwith Schiff rsquos base derived from thiourea and glutaraldehyderdquoJournal of Hazardous Materials vol 151 no 2-3 pp 372ndash3792008
[9] K Z Elwakeel and A A Atia ldquoUptake of U(VI) from aqueousmedia by magnetic Schiff rsquos base chitosan compositerdquo Journal ofCleaner Production vol 70 pp 292ndash302 2014
[10] A M Donia A A Atia E M M Moussa A M El-Sherifand M O Abd El-Magied ldquoRemoval of uranium(VI) fromaqueous solutions using glycidyl methacrylate chelating resinsrdquoHydrometallurgy vol 95 no 3-4 pp 183ndash189 2009
[11] Z Marczenko Separation and Spectrophotometric Determina-tion of Elements Ellis Harwood Chichester UK 1986
[12] S A Sadeek M A El-Sayed M M Amine and M O Abd El-Magied ldquoA chelating resin containing trihydroxybenzoic acidas the functional group synthesis and adsorption behavior forTh(IV) and U(VI) ionsrdquo Journal of Radioanalytical and NuclearChemistry vol 299 no 3 pp 1299ndash1306 2014
[13] W Dong and S C Brooks ldquoDetermination of the formationconstants of ternary complexes of uranyl and carbonate with
Journal of Engineering 11
alkaline earth metals (Mg2+ Ca2+ Sr2+ and Ba2+) using anionexchangemethodrdquoEnvironmental ScienceampTechnology vol 40no 15 pp 4689ndash4695 2006
[14] C Xiong X Liu and C Yao ldquoEffect of pH on sorptionfor RE(III) and sorption behaviors of Sm(III) by D152 resinrdquoJournal of Rare Earths vol 26 no 6 pp 851ndash856 2008
[15] A O Dada A P Olalekan A M Olatunya and O DadaldquoLangmuir Freundlich Temkin and Dubinin-Radushkevichisotherms studies of equilibrium sorption of Zn2+ unto phos-phoric acid modified rice huskrdquo Journal of Applied Chemistryvol 3 no 1 pp 38ndash45 2012
[16] V P Mpofu J Addai-Mensah and J Ralston ldquoTemperatureinfluence of nonionic polyethylene oxide and anionic polyacry-lamide on flocculation and dewatering behavior of kaolinitedispersionsrdquo Journal of Colloid and Interface Science vol 271no 1 pp 145ndash156 2004
[17] A U Itodo andHU Itodo ldquoSorption energies estimation usingDubinin-Radushkevich andTemkin adsorption isothermsrdquo LifeScience Journal vol 7 no 4 pp 31ndash39 2010
[18] K Dev R Pathak and G N Rao ldquoSorption behaviour oflanthanum(III) neodymium(III) terbium(III) thorium(IV)and uranium(VI) on Amberlite XAD-4 resin functionalizedwith bicine ligandsrdquo Talanta vol 48 no 3 pp 579ndash584 1999
[19] V K Jain A Handa S S Sait P Shrivastav and Y K AgrawalldquoPre-concentration separation and trace determination of lan-thanum(III) cerium(III) thorium(IV) and uranium(VI) onpolymer supported o-vanillinsemicarbazonerdquo Analytica Chim-ica Acta vol 429 no 2 pp 237ndash246 2001
[20] M Nogami I M Ismail M Yamaguchi and K SuzukildquoSynthesis characterization and some adsorption properties ofTMMA chelating resinrdquo Journal of Solid State Chemistry vol171 no 1-2 pp 353ndash357 2003
[21] P Metilda K Sanghamitra J M Gladis G R K Naiduand T Prasada Rao ldquoAmberlite XAD-4 functionalized withsuccinic acid for the solid phase extractive preconcentrationand separation of uranium(VI)rdquo Talanta vol 65 no 1 pp 192ndash200 2005
[22] DH Phillips B GuD BWatson andC S Parmele ldquoUraniumremoval from contaminated groundwater by synthetic resinsrdquoWater Research vol 42 no 1-2 pp 260ndash268 2008
[23] Y Jung S Kim S-J Park and J M Kim ldquoApplication ofpolymer-modified nanoporous silica to adsorbents of uranylionsrdquo Colloids and Surfaces A vol 313-314 pp 162ndash166 2008
[24] G Tian J Geng Y Jin et al ldquoSorption of uranium(VI) usingoxime-grafted ordered mesoporous carbon CMK-5rdquo Journal ofHazardous Materials vol 190 no 1ndash3 pp 442ndash450 2011
[25] T S Anirudhan J Nima and P L Divya ldquoAdsorption and sep-aration behavior of uranium(VI) by 4-vinylpyridine-grafted-vinyltriethoxysilane-cellulose ion imprinted polymerrdquo Journalof Environmental Chemical Engineering vol 3 no 2 pp 1267ndash1276 2015
[26] N T Tavengwa E Cukrowska and L Chimuka ldquoSynthesis ofbulk ion-imprinted polymers (IIPs) embedded with oleic acidcoated Fe
3O4for selective extraction of hexavalent uraniumrdquo
Water SA vol 40 no 4 pp 623ndash630 2014[27] M Solgy M Taghizadeh and D Ghoddocynejad ldquoAdsorption
of uranium(VI) from sulphate solutions using Amberlite IRA-402 resin equilibrium kinetics and thermodynamics studyrdquoAnnals of Nuclear Energy vol 75 pp 132ndash138 2015
[28] J Li X Yang C Bai et al ldquoA novel benzimidazole-functionalized 2-D COF material synthesis and application as
a selective solid-phase extractant for separation of uraniumrdquoJournal of Colloid and Interface Science vol 437 pp 211ndash2182015
[29] N T Tavengwa E Cukrowska and L Chimuka ldquoSelectiveadsorption of uranium (VI) on NaHCO
3leached composite
120574-methacryloxypropyltrimethoxysilane coated magnetic ion-imprinted polymers prepared by precipitation polymerizationrdquoSouth African Journal of Chemistry vol 68 pp 61ndash68 2015
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International Journal of
2 Journal of Engineering
for Ag adsorption [6] Glycidylmethacrylate resins were pre-pared in the presence and absence of iron oxide (Fe
2O3) The
conducted resins were subsequently treated with ethylenedi-amine giving the corresponding amine-chelating resins Theuptake behavior of both resins towards Cu+2 ions in aqueoussolutions using batch and column techniques was studied[7] Magnetic chitosan resin was chemically modified by apolymeric Schiff rsquos base cross-linker and used for mercury+2uptake with capacity value of 28mmolg [8] Schiff rsquos basechitosan composites with magnetic properties were preparedthrough the reaction between chitosan and polymeric Schiffbase of thioureaglutaraldehyde in the presence of magnetiteThe sorption characteristics of this composite towards U(VI)at different experimental conditions were carried out bymeans of batch and column methods where it showedsorption capacity reached 232mmolg [9]
The main target of this paper was to increase the con-centration of active sites available for interaction with themetal ionsThe target was approached through spreading theresin as a film over iron oxide particles and using a cross-linker with hydrophilic characters The other target of thispaperwas to increase the chemical andmechanical stability ofmodified glycidyl methacrylate resins with amine moiety toenhance their adsorption capacities towards U(VI) ions fromthe aqueous solutions The target was approached throughincreasing degree of cross-linking as well as modifying allparameters that affect the polymerization process such asthe continuous phase initiator diluents and polymerizationtemperature In the present work GMAMBA was preparedby suspension polymerization ofGMAwithMBA in the pres-ence of nanomagnetite particles Different amine moietieswere immobilized on the magnetic GMAMBA copolymersThe obtained magnetic resins were applied for separationof U(VI) ions from aqueous solutions The different factorsaffecting the separation process such as initial concentra-tion of the metal ion pH shaking time and temperaturewere studied Kinetic and thermodynamic parameters of theadsorption process were calculated
2 Materials and Methods
All the chemicals were of analytical grade ofMerck or Sigma-Aldrich trademark and were used as received without furtherpurification All of the solutions were prepared with freshdouble distilled water A uranium stock solution containing1000mg Lminus1 of U(VI) was prepared by dissolving 1782 g ofuranyl acetate in 1 nitric acid and diluting to 1000mL usingthe double distilled water
The U(VI) measurement was estimated spectrophoto-metrically using Arsenazo I method [11] by the PC scan-ning spectrophotometer UVVIS double beam of the typeLabomed Inc (USA)
Nanomagnetite was prepared following the modifiedMassart method [10] 100mL (02M) of Fe+3 solutions wasadded with stirring to freshly prepared 100mL (01M) ofFe+2 solutions Then 100mL of ammonia solution (30)was suddenly poured to the previously prepared Fe+3Fe+2solutions with vigorous stirring A black precipitate wasformed and was allowed to crystallize for 30min with
stirringThe precipitate was washed with deoxygenated water(water was boiled to repeal any gases and then bubbledwith nitrogen gas) under magnetic decantation until pH ofsuspension became below 75 The precipitate was dried atroom temperature to give a black powder
Magnetic GMAMBA was prepared through suspen-sion copolymerization of GMA in the presence of cross-linking agent (MBA) nanomagnetite (F
3O4) and 22-
azobis(isobutyronitrile) (AIBN) as an initiator following thepreviously reported method [10] The contents were refluxedon a water bath at 80∘C with continuous stirring for 8 h Aheavy precipitate was formed filtered off washed with waterand ethanol to remove the diluents and then dried
Two portions of the magnetic GMAMBA copolymerswere weighted 2 g each One of them was added portionwiseto the stirred solution of 10mL ethylenediamine (DA) whilethe second portion was added to diethylenetriamine (TA) inproper flasksThemixtures were placed in an oil bath at 80∘Cfor 72 h with stirring speed of 300 rpm After completionof the reaction the formed beads were simply decanted andwashed several times and then dried The obtained resinswere marked as R-1 and R-2 respectively
Adsorption experiments under controlled pH were car-ried out by adding portions of 005 g resin in a series offlasks each one containing 100mL solution of (100mg Lminus1)U(VI) ions solution The pH was adapted in the range of1ndash5 using nitric acid or sodium hydroxide solutions Theflasks were shaken on a shaking water bath model 1083(Labortechnik GmbH Germany) at 300 rpm for 2 h at 25∘CAfter equilibration the residual concentration of the metalion was determined
To conduct the time effect 005 g of R-1 or R-2 wasput in a series of flasks containing 100mL of U(VI) ionssolution (100mg Lminus1) at pH 5 The flasks were shaken ona shaking water bath for the required time period Theeffect of initial concentration of U(VI) ion was carried outat definite concentrations (20ndash120mg Lminus1) and pH 5 Thecontents of the flasks were equilibrated on a shaking waterbath while keeping the temperature at 25 30 40 and 50∘CAfter adsorption the residual U(VI) concentration of themetal ion was determined
The effect of the solidliquid ratio on the adsorptionefficiency of the studied resins was achieved by varying theamount of beads from 0025 to 0125 g in the adsorptionmedium (100mL containing 100mg Lminus1 U(VI)) while keep-ing other parameters (pH contact time and temperature)constant according to their values obtained from the previousexperiments
3 Results and Discussions
Scheme 1 shows the preparation of the magnetic GMAMBAresins and their chemical modification with DA or TAthrough epoxide ring to give R-1 and R-2 respectively asshown in Scheme 1
The structural characteristics of the resins obtained wereverified using FT-IR measurements The spectra of resinsshowed the stretching band of oxirane group of magneticGMAMBA at 910 cmminus1 disappeared in the spectra of resins
Journal of Engineering 3
CC
OC
HC
C
O
O
CH
CNH
CNH
C
O
CC
OC
HC
C
C
O
O
CH
O
GMA MBA
Magnetic GMAMBA
HC
HC
O
Magnetic GMAMBA
OEmbedded magnetite
Polymeric film
R
C
HO HN
HC
HOHN
R
NH
NH
HN
R
HC
CNH
CNH
CCH
C
O O
R
DA or TA
R
R
R
H2C
H2C
CH3
CH3
H2
H2
H2H2H2H2
H2
H2
CH2
CH2
CH2
CH2
CH2
CH2
R1 = H or CH2CH2NH2
+
R = resin matrix
R1
R1NH2
R-1 or R-2
+
Scheme 1 Chemical preparation of resins containing nanomagnetite
R-1 and R-2 Moreover the spectra of R-1 and R-2 are char-acterized by ]NH
2at 3443 cmminus1 This indicates the success of
modification process Energy dispersive X-raymeasurements(EDX) of R-1 and R-2 showed that the resin contains a weightpercentage of 10 of Fe
3O4 The resin particles of magnetite
R-1 and R-2 were characterized by dynamic light scattering(DLS) The average sizes of magnetite particles were 18ndash92 nm while the average sizes of R-1 and R-2 particles were615 nmndash4801 nm
The chemical stability of R-1 and R-2 in acid and alkalinemedia was tested by shaking a 05 g portion of the resinsin turn with 100mL of 1M HCl and 1M NaOH for 24 hThe resins were then filtered off and washed with water Theadsorption capacities after the treatments were reduced byonly 5ndash7 which were denoted as desirable stability of theresin No obvious leakage of resins and change of resins wereobserved in the experimental process
31 Effect of pH Sorption of U(VI) from aqueous solutionsby R-1 and R-2 was determined under noncompetitive con-ditions at different pH values as shown in Figure 1 The
0
60
120
180
0 1 2 3 4 5 6pH
qe
(mg
g)
R-1R-2
Figure 1 Effect of pH on adsorption process
sorption of uranium was found to be increased as thesolution pH increased The maximum sorption capacitieswere observed at pH 5 for R-1 and R-2 As indicated in Table 1
4 Journal of Engineering
Figure 2 The scanning electron microscopy images of the studied resins before and after uranium sorption
Table 1 Adsorption capacities of uranium by different adsorbents
Chelating resins 119902119890(mgg) Reference
Modified polystyrene 595 [18]Calix[4]resorcinarene 640 [19]Tetramethylmalonamide (TMMA) 1190 [20]Amberlite XAD-4-succinic acid 123 [21]Modified Dowextrade 12K 498 [22]Nanoporous silica 294 [23]Mesoporous carbon CMK-5 652 [24]4-Vinylpyridine 134 [25]Salicylaldoxime and 4-vinylpyridine 12 [26]IRA-402 resin 213 [27]Covalent organic frameworks 81 [28]Salicylaldoxime and 4-vinylpyridine 115 [29]R-1 92 This workR-2 158 This work
the investigated resins were characterized by higher 119902119890value
relative to that reported by othersThe surface morphology of the studied resins before
and after uranium sorption was studied by SEM analysis(Figure 2) The surface morphology of the uranium loadedresins showed a large particle with close-packed plane
surface which could be assigned to the sorption of uraniumions onto the surface of the studied loaded resins
The observed lower sorption of U(VI) ions in higheracidic medium may be attributed to the partial protonationof the amino groups to give positively charged protonatedamino groups that do not promote U(VI) adsorption due torepulsion force
Hydrolysis of U(VI) ions was observed to begin at pH gt 5and various positively charged hydrolyzed uranium speciesexist ([(UO
2)3(OH)4]2+ [(UO
2)2OH]3+ [(UO
2)3(OH)]5+
and [(UO2)4(OH)]7+) which have lower affinity to R-1 and R-
2 Also negatively charged uranium species ([UO2(OH)4]2minus
and [(UO2)3(OH)7]minus) were found at higher pH values which
cannot react with R-1 and R-2 [10ndash12]The values of the experimentalmaximum sorption capac-
ities were 92 and 158mgg for R-1 and R-2 The values of themaximum sorption of resins are related to their amine groupcontent of 55 and 81mmolg for R-1 and R-2 The higherconcentration of amine active sites in case of R-1 and R-2relative to the free magnetite ones (38 and 54mmolg) mayindicate the formation of extended thin film of the resin overthe metal oxide particles This would allow the active siteshidden within the core of the resin matrix to become moreexposed for interaction with metal ions [10]
The mechanism of interaction between U(VI) ions andamine active sites on R-1 and R-2 resins may be relatedto their coordination modes U(VI) ions can coordinate by
Journal of Engineering 5
0
60
120
180
0 30 60 90Time (min)
qt
(mg
g)
R-1R-2
Figure 3 Effect of time on adsorption process
four five or six amine active sites of R-1 and R-2 resins[10] The molar ratios of sorbed U(VI) ions and resins activesites are 1 4 1 5 and 1 6 The experimental maximumsorption capacities of 92mgg (039mmolg) and 158mgg(066mmolg) for R-1 and R-2 are closer to the theoreticalsorption value corresponding to the molar ratio of 1 6 (092and 14mmolg for R-1 and R-2) The observed differencesbetween the experimental and expected sorption capacitiesvalues may be attributed to the nonaccessibility of all activesites for coordination with U(VI)This behavior confirms theeffect of textural properties on the nature of binding as wellas the sorption capacity
32 Effect of Contact Time and Adsorption Kinetics Sorptionof U(VI) on both R-1 and R-2 resins was investigated as afunction of contact time and the data obtained are shownin Figure 3 Uranium sorption increased as the contact timeincreased and reached its maximum sorption capacities at45 and 30min on R-1 and R-2 respectively To verify theorder of the adsorption process pseudo-first-order kineticsand pseudo-second-order kineticsmodels [10 12] were testedaccording to the following equations
Pseudo first order log (119902119890minus 119902119905) = log (119902
1st) minus1198961
2303119905
Pseudo second order 119905119902119905
=1
119896211990222nd+1
119902119890
119905
(1)
where 119902119890is the maximum experimental sorption capacity
(mg gminus1) 119902119905is the experimental sorption capacity at time (119905)
(mg gminus1) 1199021st is the calculated sorption capacity according
to pseudo-first-order model (mg gminus1) 1198961is the rate constant
of pseudo-first-order (minminus1) 1199022nd is the calculated sorption
capacity according to pseudo-second-order model (mg gminus1)and 119896
2is the rate constant of pseudo-second-order (minminus1)
Values of 1198961and 119902
1st were calculated from the slope andintercept values of plotting log(119902
119890minus 119902119905) versus (119905) as shown in
Figure 4 The plot of 119905119902119905versus (119905) (Figure 5) gives a straight
line with slope and intercept equal to 1119902119890and 1119896
2119902119890
2
05
1
15
2
0 10 20 30 40Time (min)
R-1R-2
log(qeminusqt)
Figure 4 The pseudo-first-order kinetics model
0
02
04
06
0 20 40 60Time (min)
tqt
R-1R-2
Figure 5 The pseudo-second-order kinetics model
respectivelyThe calculated values of 1198961 1199021st 1198962 and 1199022nd were
reported in Table 2The obtained data (119902 and 1198772) proved that the adsorption
rate is likely to be controlled by pseudo-second-order kineticmodel rather than the pseudo-first-order kinetic modelThe rate of adsorption is less controlled by intraparticlediffusion due to the bulky size of U(VI) ions that implies thatadsorption of U(VI) is dependent on concentration of boththe metal ions and active sites concentrations
33 Effect of Adsorption Temperature The temperature effecton U(VI) adsorption was tested as function of 4 temperaturedegrees (298 303 313 and 323) (Figure 6) An increase intemperature resulting in an increase in the amount of U(VI)adsorbed per unit mass of all resins might be attributed tothe change in surface properties of the sorbent and solubilityof the solute species with endothermic nature of the sorptionprocess
34 Adsorption Isotherms A relation between the amount ofadsorbate adsorbed on a given surface at constant temper-ature and the equilibrium concentration of the substrate in
6 Journal of Engineering
Table 2 Kinetic data for adsorption of U(VI) on R-1 and R-2 resins
Resin Experimental Pseudo-first-order kinetics Pseudo-second-order kinetics119902119890(mgg) 119902
1st (mgg) 1198961(minminus1) 119877
21199022nd (mgg) 119896
2(minminus1) 119877
2
R-1 92 5117 006 0942 100 0003 0997R-2 158 7413 007 0935 200 0002 0993
0
40
80
120
0 30 60 90
R-1
0
60
120
180
0 15 30 45
R-2
Ce (mgL)
qe
(mg
g)
Ce (mgL)
qe
(mg
g)298K303K
313K323K
298K303K
313K323K
Figure 6 Effect of adsorption temperature on adsorption process
0
03
06
09
0 20 40 60
R-1
0
005
01
015
0 10 20 30
R-2
Ce (mgL) Ce (mgL)
Ceq
e(g
L)
Ceq
e(g
L)
298K303K
313K323K
298K303K
313K323K
Figure 7 Langmuir adsorption isotherm
contact with the adsorbent is known as adsorption isothermAdsorption isotherms depend on certain parameters whosevalues express the surface properties and the affinity of thesorbent We can compute experimental results from equilib-rium experiences by several adsorption isotherm models
(1) Langmuir Model The most widely used isotherm equa-tion for modeling equilibrium data is the Langmuir modelLangmuir derived a relation between adsorbed material andits equilibrium concentration [10 13 14] The linear form ofLangmuir equation is given by
119862119890
119902119890
=119862119890
119902max+
1
119870119871119876max
(2)
where 119862119890is the equilibrium concentration of ions in solution
(mg Lminus1) 119902119890is the amount adsorbed at 119862
119890(mg gminus1) 119876max
is the maximum adsorption capacity (mg gminus1) and 119870119871is
the binding constant which is related to the energy ofadsorption (Lmgminus1) Plotting 119862
119890119902119890against 119862
119890(Figure 7)
gives a straight line with slope and intercept equal to 1119876maxand 1119870
119871119876max respectively The values of 119870
119871and 119876max at
different temperatures are reported in Table 3 The values of119870119871and119876max increase as the temperature increases Increasing
of119870119871value with increasing of temperature implies the strong
binding between U(VI) ions and the active sites at elevatedtemperatures
The thermodynamic parameters such as enthalpy change(Δ119867∘) and entropy change (Δ119878∘) corresponding to U(IV)sorption on the studied resins were calculated using VanrsquotHoff equation [10]
ln119870119871=Δ119878∘
119877minusΔ119867∘
119877119879 (3)
where 119877 is the universal gas constant (8314 Jmolminus1sdotKminus1)and 119879 is the absolute temperature (Kelvin) Plotting ln 119870
119871
against 1119879 (Figure 8) gives a straight line with interceptand slope equal to Δ119878∘119877 and minusΔ119867∘119877 respectively Thevalues of Δ119878∘ and Δ119867∘ were calculated and reported in
Journal of Engineering 7
Table 3 Isotherms parameters for the sorption of U(VI) ions
Resin Experimental 119902119890(mgg) Langmuir parameters Freundlich parameters
119870119871(Lmol) 119876Max (mgg) 119877
2119899 119870
119891(mgg) 119877
2
R-1 92 0026 100 0981 1247 3083 09907R-2 158 0133 16667 0977 1887 26485 08233
Resin Temkin parameters D-R parameters119861 (Jmol) 119860
119879(Lg) 119877
2119902119904(mgg) 119870ad (mol2kJ2) 119864 (kJmol2) 119877
2
R-1 5414 0080 0871 9454 9 times 10minus5 7454 085R-2 5127 0681 0934 1697 5 times 10minus5 100 0923
Table 4 Thermodynamic parameters for adsorption of U(VI) by R-1 and R-2 at different temperatures
Resin Temp (Kelvin) Thermodynamic parametersΔ119867∘ (kJmol) Δ119878
∘ (KJmolsdotK) 119879Δ119878∘ (kJmol) Δ119866
∘ (kJmol)
R-1
298
27328 016445
4901 minus2168303 4983 minus225313 5147 minus2414323 5312 minus2579
R-2
298
26064 01741
5188 minus2582303 5275 minus2669313 5449 minus2843323 5623 minus3017
Table 4 The positive Δ119867∘ value indicates that the adsorptionprocess is endothermic The positive value of Δ119878∘ maybe explained by the increased degree of randomness atthe resinsolution interface during the progress of sorptionprocess This phenomenon could be ascribed to liberation offree water molecules as a result of the substitution reactionbetween chelating amine active sites and hydrated U(VI)ion The Gibbs free energy of adsorption reaction (Δ119866∘) wascalculated using the following relation [10]
Δ119866∘= Δ119867
∘minus 119879Δ119878
∘ (4)
The values of Δ119866∘ values (Table 4) confirm the spon-taneous nature and feasibility of the sorption process andthe favorable U(VI) sorption takes place with increasing oftemperature
The suitability of the resins towards metal ions is throughthe values of separation factor constant (119877
119871) where 119877
119871gt 1
(unsuitable) 119877119871= 1 (linear) 0 lt 119877
119871lt 1 (suitable) 119877
119871= 0
(irreversible) [10] The value of 119877119871could be calculated from
(4)
119877119871=
1
1 + 119870119871119862119900
(5)
where 119862119900is the initial concentration of U(VI) ions (mM)
The values of 119877119871for sorption of U(VI) on R-1 and R-2
resins at different temperature were calculated and foundto lie between 0041 and 0281 indicating their suitability asadsorbents for U(VI)
(2) Freundlich Model The Freundlich isotherm model [1516] is an empirical relationship that describes the sorptionof solutes on a solid surface assuming that different sites
8
9
10
11
12
00031 00033 00035
1T (Kminus1)
ln K
L
R-1R-2
Figure 8 Vanrsquot Hoff plots for the adsorption process
with several sorption energies are involved (the surface ofadsorbent is heterogeneous)This isothermmodel is given by(3)
log 119902119890= log119870
119865+log119862119890
119899 (6)
where 119902119890(mg gminus1) and 119862
119890(mg Lminus1) are the equilibrium
concentrations of U(VI) in the solid and liquid phaserespectively 119870
119865(mg gminus1) and n are characteristic constants
related to the relative sorption capacity of the sorbent and theintensity of sorption respectively The higher the 1119899 valueis the more favorable the adsorption is generally 119899 lt 1 1119899and log119870
119865are the slope and intercept respectively given by
8 Journal of Engineering
0
05
1
15
2
25
0 05 1 15 2
log q
e
log Ce
R-1R-2
Figure 9 Freundlich adsorption isotherms
plotting log 119902119890against log119862
119890 The Freundlich plot (Figure 9)
gave a slope less than unity indicating the nonlinear sorptionbehavior with U(VI) in the concentration range studiedThe observed values of 119870
119865of R-1 and R-2 were found
to be 305 and 2649 (mg gminus1) The values of equilibriumsorption capacity and correlation coefficients of Langmuirequation (119876max) are more consistent with the experimentaldata than Freundlich isothermmodelTherefore the sorptionreaction is more favorable by Langmuir model confirmingthe monolayer coverage of uranium onto the amine resins
(3) Temkinrsquos Model The derivation of the Temkin isothermassumes that the fall in the heat of sorption is linear ratherthan logarithmic as implied in the Freundlich equation [1516] The linear form of Temkin isotherm is given by thefollowing equation
119902119890=119877119879
119887ln119860119879+119877119879
119887ln119862119890
119861 =119877119879
119887
119902119890= 119861 ln119860
119879+ 119861 ln119862
119890
(7)
where 119860119879is Temkin isotherm equilibrium binding constant
(Lg) 119887 is Temkin isotherm constant 119877 is universal gasconstant (8314 JmolK) 119879 is temperature at 298K and 119861is constant related to heat of sorption (Jmol) where 119902
119890
(mg gminus1) and 119862119890(mg Lminus1) are the equilibrium concentrations
of U(VI) in the solid and liquid phase respectively Plotting119902119890versus ln119862
119890(Figure 10) should give a straight line if the
adsorption energy decreases linearly with increasing surfacecoverage According to the given relation of 119902
119890versus ln119862
119890
the estimated 119861 values of R-1 and R-2 were 5127ndash5414 Jmolthat indicate the favorability of the chemical adsorptionprocess
341 Dubinin-Radushkevich Isotherm Model The Dubinin-Radushkevich (D-R) isotherm model is more general thanthe Langmuir isotherm as its deviation is not based on ideal
0
60
120
180
0 1 2 3 4 5
qe
ln Ce
R-1R-2
Figure 10 Temkin adsorption isotherms
assumptions such as equipotential of sorption sites absenceof steric hindrances between sorbed and incoming particlesand surface homogeneity onmicroscopic levelThis isothermmodel is a temperature-dependentmodel used to estimate thecharacteristic porosity in addition to the apparent energy ofadsorption as well as expressing the adsorption mechanism[15 17] The model is represented by the following equations
119902119890= (119902119904) exp(minus119870ad (119877119879 ln [1 +
1
119862119890
])
2
)
120576 = 119877119879 ln [1 + 1
119862119890
]
119902119890= (119902119904) exp (minus119870ad120576
2)
(8)
where 119902119890is the amount of adsorbate in the adsorbent at
equilibrium (mgg) 119902119904is the theoretical isotherm saturation
capacity (mgg)119870ad is the D-R isotherm constant (mol2kJ2)related to free energy of sorption 120576 is the D-R isothermconstant 119877 represents the gas constant (8314 Jmol K) 119879 isabsolute temperature (K) and 119862
119890is adsorbate equilibrium
concentration (mgL) The linearity of D-R isotherm modelis represented by the following equation
ln 119902119890= ln 119902
119904minus 119870ad120576
2 (9)
A plot of ln 119902119890versus 1205762 yielded straight lines indicating a
good fit of the isotherm to the experimental data (Figure 11)and the values of 119902
119904and119870ad for D-R isothermwere calculated
(Table 3) 119902119904and 1198772 values were observed that this isotherm
also gave very good description of the sorption process Thehigh values of 119902
119904show high sorption capacity The approach
was usually applied to distinguish the physical and chemicaladsorption of metal ions with its mean free energy permolecule of adsorbate The apparent energy (119864 = KJmol2) ofadsorption can be computed calculated using the followingrelation
119864 = [1
radic2119870ad] (10)
Journal of Engineering 9
3
4
5
6
0 20000 40000 60000
R-1R-2
ln q e
1205762
Figure 11 Dubinin-Radushkevich isotherm model
0
25
50
75
100
0
50
100
150
200
250
0 05 1 15
Adso
rptio
n ca
paci
ty (m
gg)
Solidliquid (mgmL)
Adso
rptio
n effi
cien
cy (
)
R-1 (mgg)R-2 (mgg)R-1 ()R-2 ()
Figure 12 The effect of the solidliquid ratio on the adsorptionefficiency
The values of the apparent energy of adsorption alsodepict chemisorption process
35 SolidLiquid Ratio The effect of the solidliquid ratio onthe adsorption efficiency of the studied resins was achievedusing variable amounts of R-1 and R-2 resins (0025 to 0125 g)in 100mL of the adsorption medium and the results wereshowed in Figure 12 The adsorption efficiency of the resinsincreased with increasing their dose while the adsorptioncapacities decreased This result is reasonable if we considerthat as the higher resin dose in the solution as the higheravailability of active sites for metal ion adsorption
36 Resin Regeneration For desorption studies 05 g of theuranium loaded dry resin with uranium was gently washedwith distilled water to remove any unabsorbed metal ionsand then shaken with 100mL of 01M HNO
3for 30min
and finally the uranium concentration was determined in thefiltrate All the experiments were performed in duplicate withexperimental error plusmn05ndash2 After the uranium elution theresins were regenerated by washing with 1M NaOH solutionfollowed by washing with distilled water hence the resinbecame regenerated and ready for the next use Regenerationefficiency was found to be about 90ndash96 for two resins over3 cycles
It is worth mentioning that using of the eluted resinswithout alkalinewashing failed to adsorbmore uranium ionswhich can be ascribed to the protonation of the amino activegroups that prevent the U(VI) ions adsorption Accordinglytreatment with the alkaline solution converted these proto-nated groups into free ones which have the affinity towardsthe U(VI) ions
37 Application of the Studied Resins for Granite SamplesThree granite rock samples were collected from Gabal Gattarpluton located inNorth EasternDesert of EgyptThe sampleswere crushed and ground to minus200 mesh size and analyzed byconventional wet chemical techniques for their major oxidecompositions as well as by XRF for some trace elements Thechemical analysis of the studied granitic samples is given inTable 5 The granitic samples contain high concentration ofFe2O3(t) Rb Y Nb U and Th and low concentration of Sr
and Ba compared with similar Egyptian granitesFor thework purpose the uranium content in the granitic
samples was selectively leached using nitric acid solution(2M) for 6 hours at 60∘C The reacted slurry was filteredand washed with hot water The obtained filtrate was treatedwith R-1 and R-2 for the uranium separation The uptakeresults of U(VI) ions (Table 6) showed that both the resinsdisplayed higher removal efficiency towards U(VI) relative toother metal ions present in sample solution
4 Conclusion
Magnetic glycidyl methacrylate resin particles with nano-magnetite core and glycidyl methacrylateNN1015840-methylene-bis-acrylamide resin shell were prepared and modified withDA and TA The studied resins showed high adsorptioncapacities towards uranium ions reached 92 and 158mggfor R-1 and R-2 respectively The results revealed that thepseudo-second-order sorption is the predominant mech-anism The amount of U(VI) adsorbed per unit mass ofall resins increased as temperature increased showing theendothermic nature of the sorption process The experimen-tal results from equilibrium experiences were computed byseveral adsorption isotherm models Langmuir FreundlichTemkin and Dubinin-Radushkevich isotherm model Theresults showed that the sorption reaction is more favorableby Langmuir model confirming the monolayer coverage ofuraniumonto the amine resins and indicate the favorability ofthe chemical adsorption processThe positive heat of adsorp-tion indicates that the adsorption process is endothermicThe
10 Journal of Engineering
Table 5 Chemical analysis of granitic samples
Sample Majorconstituent Trace
constituentConcentration
ppm
1
SiO2
735 U 4000AL2O3
128 Th 300Fe2O3
25 Rare earth 270CaO 13 Rb 225Na2O 26 Zr 197
MgO 05 Y 126K2O 24
2
SiO2
735 U 3200AL2O3
138 Th 190Fe2O3
36 Rare earth 270CaO 14 Rb mdashNa2O 06 Zr 400
MgO 05 Y 197K2O 24
3
SiO2
725 U 2700AL2O3
128 Th 260Fe2O3
25 Rare earth 250CaO 13 Rb 437Na2O 39 Zr 284
MgO 05 Y 135K2O 34
Table 6 Results of treatment of the granite samples with the studiedresins
Resin Metal ion Removal efficiency ()Sample 1 Sample 2 Sample 3
R-1U(VI) 93 93 928Fe(III) 26 25 26RE2O3
15 15 15
R-2U(VI) 995 992 99Fe(III) 31 31 31RE2O3
55 80 85
positive value of Δ119878∘ points to increasing of the randomnessdegree at the resinsolution interface during the progress ofsorption process The negative values of Δ119866∘ values confirmthe spontaneous nature of the sorption process
Finally it can be concluded that
(1) the prepared magnetite-cored resins have advantagetoward the filtration process where the magnetiteparticles impart the magnetic properties to the beadsthat allow rapid and easy separation of beads by theapplication of an external magnetic field avoidingsome technical problems arising due to using thetraditional filter papers
(2) the magnetite core allows more spreading of theactive group on the surface of resin particles thatenhance the adsorption efficiency comparing to othernonmagnetite core resins [10]
(3) the prepared resins are recommended as effectiveadsorbate materials regarding separation of uraniumions from their bearing solutions particularly in thepresence of other competitive metal ions
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] O Philippova A Barabanova V Molchanov and A KhokhlovldquoMagnetic polymer beads recent trends and developments insynthetic design and applicationsrdquo European Polymer Journalvol 47 no 4 pp 542ndash559 2011
[2] Q Yuan and R A Williams ldquoLarge scale manufacture ofmagnetic polymer particles using membranes and microfluidicdevicesrdquo China Particuology vol 5 no 1-2 pp 26ndash42 2007
[3] C-Y Chen C-L Chiang and P-C Huang ldquoAdsorptions ofheavy metal ions by a magnetic chelating resin containinghydroxy and iminodiacetate groupsrdquo Separation and Purifica-tion Technology vol 50 no 1 pp 15ndash21 2006
[4] D Horak B Rittich and A Spanova ldquoCarboxyl-functionalizedmagnetic microparticle carrier for isolation and identificationof DNA in dairy productsrdquo Journal of Magnetism and MagneticMaterials vol 311 no 1 pp 249ndash254 2007
[5] AAAtia AMDonia andA E Shahin ldquoStudies on the uptakebehavior of a magnetic Co
3O4-containing resin for Ni(II)
Cu(II) andHg(II) from their aqueous solutionsrdquo Separation andPurification Technology vol 46 no 3 pp 208ndash213 2005
[6] A M Donia A A Atia H A El-Boraey and D H MabroukldquoAdsorption of Ag(I) on glycidyl methacrylateNN1015840-methylenebis-acrylamide chelating resins with embedded iron oxiderdquoSeparation and Purification Technology vol 48 no 3 pp 281ndash287 2006
[7] A M Donia A A Atia H A El-Boraey and D H MabroukldquoUptake studies of copper(II) on glycidyl methacrylate chelat-ing resin containing Fe
2O3particlesrdquo Separation and Purifica-
tion Technology vol 49 no 1 pp 64ndash70 2006[8] A M Donia A A Atia and K Z Elwakeel ldquoSelective sepa-
ration of mercury(II) using magnetic chitosan resin modifiedwith Schiff rsquos base derived from thiourea and glutaraldehyderdquoJournal of Hazardous Materials vol 151 no 2-3 pp 372ndash3792008
[9] K Z Elwakeel and A A Atia ldquoUptake of U(VI) from aqueousmedia by magnetic Schiff rsquos base chitosan compositerdquo Journal ofCleaner Production vol 70 pp 292ndash302 2014
[10] A M Donia A A Atia E M M Moussa A M El-Sherifand M O Abd El-Magied ldquoRemoval of uranium(VI) fromaqueous solutions using glycidyl methacrylate chelating resinsrdquoHydrometallurgy vol 95 no 3-4 pp 183ndash189 2009
[11] Z Marczenko Separation and Spectrophotometric Determina-tion of Elements Ellis Harwood Chichester UK 1986
[12] S A Sadeek M A El-Sayed M M Amine and M O Abd El-Magied ldquoA chelating resin containing trihydroxybenzoic acidas the functional group synthesis and adsorption behavior forTh(IV) and U(VI) ionsrdquo Journal of Radioanalytical and NuclearChemistry vol 299 no 3 pp 1299ndash1306 2014
[13] W Dong and S C Brooks ldquoDetermination of the formationconstants of ternary complexes of uranyl and carbonate with
Journal of Engineering 11
alkaline earth metals (Mg2+ Ca2+ Sr2+ and Ba2+) using anionexchangemethodrdquoEnvironmental ScienceampTechnology vol 40no 15 pp 4689ndash4695 2006
[14] C Xiong X Liu and C Yao ldquoEffect of pH on sorptionfor RE(III) and sorption behaviors of Sm(III) by D152 resinrdquoJournal of Rare Earths vol 26 no 6 pp 851ndash856 2008
[15] A O Dada A P Olalekan A M Olatunya and O DadaldquoLangmuir Freundlich Temkin and Dubinin-Radushkevichisotherms studies of equilibrium sorption of Zn2+ unto phos-phoric acid modified rice huskrdquo Journal of Applied Chemistryvol 3 no 1 pp 38ndash45 2012
[16] V P Mpofu J Addai-Mensah and J Ralston ldquoTemperatureinfluence of nonionic polyethylene oxide and anionic polyacry-lamide on flocculation and dewatering behavior of kaolinitedispersionsrdquo Journal of Colloid and Interface Science vol 271no 1 pp 145ndash156 2004
[17] A U Itodo andHU Itodo ldquoSorption energies estimation usingDubinin-Radushkevich andTemkin adsorption isothermsrdquo LifeScience Journal vol 7 no 4 pp 31ndash39 2010
[18] K Dev R Pathak and G N Rao ldquoSorption behaviour oflanthanum(III) neodymium(III) terbium(III) thorium(IV)and uranium(VI) on Amberlite XAD-4 resin functionalizedwith bicine ligandsrdquo Talanta vol 48 no 3 pp 579ndash584 1999
[19] V K Jain A Handa S S Sait P Shrivastav and Y K AgrawalldquoPre-concentration separation and trace determination of lan-thanum(III) cerium(III) thorium(IV) and uranium(VI) onpolymer supported o-vanillinsemicarbazonerdquo Analytica Chim-ica Acta vol 429 no 2 pp 237ndash246 2001
[20] M Nogami I M Ismail M Yamaguchi and K SuzukildquoSynthesis characterization and some adsorption properties ofTMMA chelating resinrdquo Journal of Solid State Chemistry vol171 no 1-2 pp 353ndash357 2003
[21] P Metilda K Sanghamitra J M Gladis G R K Naiduand T Prasada Rao ldquoAmberlite XAD-4 functionalized withsuccinic acid for the solid phase extractive preconcentrationand separation of uranium(VI)rdquo Talanta vol 65 no 1 pp 192ndash200 2005
[22] DH Phillips B GuD BWatson andC S Parmele ldquoUraniumremoval from contaminated groundwater by synthetic resinsrdquoWater Research vol 42 no 1-2 pp 260ndash268 2008
[23] Y Jung S Kim S-J Park and J M Kim ldquoApplication ofpolymer-modified nanoporous silica to adsorbents of uranylionsrdquo Colloids and Surfaces A vol 313-314 pp 162ndash166 2008
[24] G Tian J Geng Y Jin et al ldquoSorption of uranium(VI) usingoxime-grafted ordered mesoporous carbon CMK-5rdquo Journal ofHazardous Materials vol 190 no 1ndash3 pp 442ndash450 2011
[25] T S Anirudhan J Nima and P L Divya ldquoAdsorption and sep-aration behavior of uranium(VI) by 4-vinylpyridine-grafted-vinyltriethoxysilane-cellulose ion imprinted polymerrdquo Journalof Environmental Chemical Engineering vol 3 no 2 pp 1267ndash1276 2015
[26] N T Tavengwa E Cukrowska and L Chimuka ldquoSynthesis ofbulk ion-imprinted polymers (IIPs) embedded with oleic acidcoated Fe
3O4for selective extraction of hexavalent uraniumrdquo
Water SA vol 40 no 4 pp 623ndash630 2014[27] M Solgy M Taghizadeh and D Ghoddocynejad ldquoAdsorption
of uranium(VI) from sulphate solutions using Amberlite IRA-402 resin equilibrium kinetics and thermodynamics studyrdquoAnnals of Nuclear Energy vol 75 pp 132ndash138 2015
[28] J Li X Yang C Bai et al ldquoA novel benzimidazole-functionalized 2-D COF material synthesis and application as
a selective solid-phase extractant for separation of uraniumrdquoJournal of Colloid and Interface Science vol 437 pp 211ndash2182015
[29] N T Tavengwa E Cukrowska and L Chimuka ldquoSelectiveadsorption of uranium (VI) on NaHCO
3leached composite
120574-methacryloxypropyltrimethoxysilane coated magnetic ion-imprinted polymers prepared by precipitation polymerizationrdquoSouth African Journal of Chemistry vol 68 pp 61ndash68 2015
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International Journal of
Journal of Engineering 3
CC
OC
HC
C
O
O
CH
CNH
CNH
C
O
CC
OC
HC
C
C
O
O
CH
O
GMA MBA
Magnetic GMAMBA
HC
HC
O
Magnetic GMAMBA
OEmbedded magnetite
Polymeric film
R
C
HO HN
HC
HOHN
R
NH
NH
HN
R
HC
CNH
CNH
CCH
C
O O
R
DA or TA
R
R
R
H2C
H2C
CH3
CH3
H2
H2
H2H2H2H2
H2
H2
CH2
CH2
CH2
CH2
CH2
CH2
R1 = H or CH2CH2NH2
+
R = resin matrix
R1
R1NH2
R-1 or R-2
+
Scheme 1 Chemical preparation of resins containing nanomagnetite
R-1 and R-2 Moreover the spectra of R-1 and R-2 are char-acterized by ]NH
2at 3443 cmminus1 This indicates the success of
modification process Energy dispersive X-raymeasurements(EDX) of R-1 and R-2 showed that the resin contains a weightpercentage of 10 of Fe
3O4 The resin particles of magnetite
R-1 and R-2 were characterized by dynamic light scattering(DLS) The average sizes of magnetite particles were 18ndash92 nm while the average sizes of R-1 and R-2 particles were615 nmndash4801 nm
The chemical stability of R-1 and R-2 in acid and alkalinemedia was tested by shaking a 05 g portion of the resinsin turn with 100mL of 1M HCl and 1M NaOH for 24 hThe resins were then filtered off and washed with water Theadsorption capacities after the treatments were reduced byonly 5ndash7 which were denoted as desirable stability of theresin No obvious leakage of resins and change of resins wereobserved in the experimental process
31 Effect of pH Sorption of U(VI) from aqueous solutionsby R-1 and R-2 was determined under noncompetitive con-ditions at different pH values as shown in Figure 1 The
0
60
120
180
0 1 2 3 4 5 6pH
qe
(mg
g)
R-1R-2
Figure 1 Effect of pH on adsorption process
sorption of uranium was found to be increased as thesolution pH increased The maximum sorption capacitieswere observed at pH 5 for R-1 and R-2 As indicated in Table 1
4 Journal of Engineering
Figure 2 The scanning electron microscopy images of the studied resins before and after uranium sorption
Table 1 Adsorption capacities of uranium by different adsorbents
Chelating resins 119902119890(mgg) Reference
Modified polystyrene 595 [18]Calix[4]resorcinarene 640 [19]Tetramethylmalonamide (TMMA) 1190 [20]Amberlite XAD-4-succinic acid 123 [21]Modified Dowextrade 12K 498 [22]Nanoporous silica 294 [23]Mesoporous carbon CMK-5 652 [24]4-Vinylpyridine 134 [25]Salicylaldoxime and 4-vinylpyridine 12 [26]IRA-402 resin 213 [27]Covalent organic frameworks 81 [28]Salicylaldoxime and 4-vinylpyridine 115 [29]R-1 92 This workR-2 158 This work
the investigated resins were characterized by higher 119902119890value
relative to that reported by othersThe surface morphology of the studied resins before
and after uranium sorption was studied by SEM analysis(Figure 2) The surface morphology of the uranium loadedresins showed a large particle with close-packed plane
surface which could be assigned to the sorption of uraniumions onto the surface of the studied loaded resins
The observed lower sorption of U(VI) ions in higheracidic medium may be attributed to the partial protonationof the amino groups to give positively charged protonatedamino groups that do not promote U(VI) adsorption due torepulsion force
Hydrolysis of U(VI) ions was observed to begin at pH gt 5and various positively charged hydrolyzed uranium speciesexist ([(UO
2)3(OH)4]2+ [(UO
2)2OH]3+ [(UO
2)3(OH)]5+
and [(UO2)4(OH)]7+) which have lower affinity to R-1 and R-
2 Also negatively charged uranium species ([UO2(OH)4]2minus
and [(UO2)3(OH)7]minus) were found at higher pH values which
cannot react with R-1 and R-2 [10ndash12]The values of the experimentalmaximum sorption capac-
ities were 92 and 158mgg for R-1 and R-2 The values of themaximum sorption of resins are related to their amine groupcontent of 55 and 81mmolg for R-1 and R-2 The higherconcentration of amine active sites in case of R-1 and R-2relative to the free magnetite ones (38 and 54mmolg) mayindicate the formation of extended thin film of the resin overthe metal oxide particles This would allow the active siteshidden within the core of the resin matrix to become moreexposed for interaction with metal ions [10]
The mechanism of interaction between U(VI) ions andamine active sites on R-1 and R-2 resins may be relatedto their coordination modes U(VI) ions can coordinate by
Journal of Engineering 5
0
60
120
180
0 30 60 90Time (min)
qt
(mg
g)
R-1R-2
Figure 3 Effect of time on adsorption process
four five or six amine active sites of R-1 and R-2 resins[10] The molar ratios of sorbed U(VI) ions and resins activesites are 1 4 1 5 and 1 6 The experimental maximumsorption capacities of 92mgg (039mmolg) and 158mgg(066mmolg) for R-1 and R-2 are closer to the theoreticalsorption value corresponding to the molar ratio of 1 6 (092and 14mmolg for R-1 and R-2) The observed differencesbetween the experimental and expected sorption capacitiesvalues may be attributed to the nonaccessibility of all activesites for coordination with U(VI)This behavior confirms theeffect of textural properties on the nature of binding as wellas the sorption capacity
32 Effect of Contact Time and Adsorption Kinetics Sorptionof U(VI) on both R-1 and R-2 resins was investigated as afunction of contact time and the data obtained are shownin Figure 3 Uranium sorption increased as the contact timeincreased and reached its maximum sorption capacities at45 and 30min on R-1 and R-2 respectively To verify theorder of the adsorption process pseudo-first-order kineticsand pseudo-second-order kineticsmodels [10 12] were testedaccording to the following equations
Pseudo first order log (119902119890minus 119902119905) = log (119902
1st) minus1198961
2303119905
Pseudo second order 119905119902119905
=1
119896211990222nd+1
119902119890
119905
(1)
where 119902119890is the maximum experimental sorption capacity
(mg gminus1) 119902119905is the experimental sorption capacity at time (119905)
(mg gminus1) 1199021st is the calculated sorption capacity according
to pseudo-first-order model (mg gminus1) 1198961is the rate constant
of pseudo-first-order (minminus1) 1199022nd is the calculated sorption
capacity according to pseudo-second-order model (mg gminus1)and 119896
2is the rate constant of pseudo-second-order (minminus1)
Values of 1198961and 119902
1st were calculated from the slope andintercept values of plotting log(119902
119890minus 119902119905) versus (119905) as shown in
Figure 4 The plot of 119905119902119905versus (119905) (Figure 5) gives a straight
line with slope and intercept equal to 1119902119890and 1119896
2119902119890
2
05
1
15
2
0 10 20 30 40Time (min)
R-1R-2
log(qeminusqt)
Figure 4 The pseudo-first-order kinetics model
0
02
04
06
0 20 40 60Time (min)
tqt
R-1R-2
Figure 5 The pseudo-second-order kinetics model
respectivelyThe calculated values of 1198961 1199021st 1198962 and 1199022nd were
reported in Table 2The obtained data (119902 and 1198772) proved that the adsorption
rate is likely to be controlled by pseudo-second-order kineticmodel rather than the pseudo-first-order kinetic modelThe rate of adsorption is less controlled by intraparticlediffusion due to the bulky size of U(VI) ions that implies thatadsorption of U(VI) is dependent on concentration of boththe metal ions and active sites concentrations
33 Effect of Adsorption Temperature The temperature effecton U(VI) adsorption was tested as function of 4 temperaturedegrees (298 303 313 and 323) (Figure 6) An increase intemperature resulting in an increase in the amount of U(VI)adsorbed per unit mass of all resins might be attributed tothe change in surface properties of the sorbent and solubilityof the solute species with endothermic nature of the sorptionprocess
34 Adsorption Isotherms A relation between the amount ofadsorbate adsorbed on a given surface at constant temper-ature and the equilibrium concentration of the substrate in
6 Journal of Engineering
Table 2 Kinetic data for adsorption of U(VI) on R-1 and R-2 resins
Resin Experimental Pseudo-first-order kinetics Pseudo-second-order kinetics119902119890(mgg) 119902
1st (mgg) 1198961(minminus1) 119877
21199022nd (mgg) 119896
2(minminus1) 119877
2
R-1 92 5117 006 0942 100 0003 0997R-2 158 7413 007 0935 200 0002 0993
0
40
80
120
0 30 60 90
R-1
0
60
120
180
0 15 30 45
R-2
Ce (mgL)
qe
(mg
g)
Ce (mgL)
qe
(mg
g)298K303K
313K323K
298K303K
313K323K
Figure 6 Effect of adsorption temperature on adsorption process
0
03
06
09
0 20 40 60
R-1
0
005
01
015
0 10 20 30
R-2
Ce (mgL) Ce (mgL)
Ceq
e(g
L)
Ceq
e(g
L)
298K303K
313K323K
298K303K
313K323K
Figure 7 Langmuir adsorption isotherm
contact with the adsorbent is known as adsorption isothermAdsorption isotherms depend on certain parameters whosevalues express the surface properties and the affinity of thesorbent We can compute experimental results from equilib-rium experiences by several adsorption isotherm models
(1) Langmuir Model The most widely used isotherm equa-tion for modeling equilibrium data is the Langmuir modelLangmuir derived a relation between adsorbed material andits equilibrium concentration [10 13 14] The linear form ofLangmuir equation is given by
119862119890
119902119890
=119862119890
119902max+
1
119870119871119876max
(2)
where 119862119890is the equilibrium concentration of ions in solution
(mg Lminus1) 119902119890is the amount adsorbed at 119862
119890(mg gminus1) 119876max
is the maximum adsorption capacity (mg gminus1) and 119870119871is
the binding constant which is related to the energy ofadsorption (Lmgminus1) Plotting 119862
119890119902119890against 119862
119890(Figure 7)
gives a straight line with slope and intercept equal to 1119876maxand 1119870
119871119876max respectively The values of 119870
119871and 119876max at
different temperatures are reported in Table 3 The values of119870119871and119876max increase as the temperature increases Increasing
of119870119871value with increasing of temperature implies the strong
binding between U(VI) ions and the active sites at elevatedtemperatures
The thermodynamic parameters such as enthalpy change(Δ119867∘) and entropy change (Δ119878∘) corresponding to U(IV)sorption on the studied resins were calculated using VanrsquotHoff equation [10]
ln119870119871=Δ119878∘
119877minusΔ119867∘
119877119879 (3)
where 119877 is the universal gas constant (8314 Jmolminus1sdotKminus1)and 119879 is the absolute temperature (Kelvin) Plotting ln 119870
119871
against 1119879 (Figure 8) gives a straight line with interceptand slope equal to Δ119878∘119877 and minusΔ119867∘119877 respectively Thevalues of Δ119878∘ and Δ119867∘ were calculated and reported in
Journal of Engineering 7
Table 3 Isotherms parameters for the sorption of U(VI) ions
Resin Experimental 119902119890(mgg) Langmuir parameters Freundlich parameters
119870119871(Lmol) 119876Max (mgg) 119877
2119899 119870
119891(mgg) 119877
2
R-1 92 0026 100 0981 1247 3083 09907R-2 158 0133 16667 0977 1887 26485 08233
Resin Temkin parameters D-R parameters119861 (Jmol) 119860
119879(Lg) 119877
2119902119904(mgg) 119870ad (mol2kJ2) 119864 (kJmol2) 119877
2
R-1 5414 0080 0871 9454 9 times 10minus5 7454 085R-2 5127 0681 0934 1697 5 times 10minus5 100 0923
Table 4 Thermodynamic parameters for adsorption of U(VI) by R-1 and R-2 at different temperatures
Resin Temp (Kelvin) Thermodynamic parametersΔ119867∘ (kJmol) Δ119878
∘ (KJmolsdotK) 119879Δ119878∘ (kJmol) Δ119866
∘ (kJmol)
R-1
298
27328 016445
4901 minus2168303 4983 minus225313 5147 minus2414323 5312 minus2579
R-2
298
26064 01741
5188 minus2582303 5275 minus2669313 5449 minus2843323 5623 minus3017
Table 4 The positive Δ119867∘ value indicates that the adsorptionprocess is endothermic The positive value of Δ119878∘ maybe explained by the increased degree of randomness atthe resinsolution interface during the progress of sorptionprocess This phenomenon could be ascribed to liberation offree water molecules as a result of the substitution reactionbetween chelating amine active sites and hydrated U(VI)ion The Gibbs free energy of adsorption reaction (Δ119866∘) wascalculated using the following relation [10]
Δ119866∘= Δ119867
∘minus 119879Δ119878
∘ (4)
The values of Δ119866∘ values (Table 4) confirm the spon-taneous nature and feasibility of the sorption process andthe favorable U(VI) sorption takes place with increasing oftemperature
The suitability of the resins towards metal ions is throughthe values of separation factor constant (119877
119871) where 119877
119871gt 1
(unsuitable) 119877119871= 1 (linear) 0 lt 119877
119871lt 1 (suitable) 119877
119871= 0
(irreversible) [10] The value of 119877119871could be calculated from
(4)
119877119871=
1
1 + 119870119871119862119900
(5)
where 119862119900is the initial concentration of U(VI) ions (mM)
The values of 119877119871for sorption of U(VI) on R-1 and R-2
resins at different temperature were calculated and foundto lie between 0041 and 0281 indicating their suitability asadsorbents for U(VI)
(2) Freundlich Model The Freundlich isotherm model [1516] is an empirical relationship that describes the sorptionof solutes on a solid surface assuming that different sites
8
9
10
11
12
00031 00033 00035
1T (Kminus1)
ln K
L
R-1R-2
Figure 8 Vanrsquot Hoff plots for the adsorption process
with several sorption energies are involved (the surface ofadsorbent is heterogeneous)This isothermmodel is given by(3)
log 119902119890= log119870
119865+log119862119890
119899 (6)
where 119902119890(mg gminus1) and 119862
119890(mg Lminus1) are the equilibrium
concentrations of U(VI) in the solid and liquid phaserespectively 119870
119865(mg gminus1) and n are characteristic constants
related to the relative sorption capacity of the sorbent and theintensity of sorption respectively The higher the 1119899 valueis the more favorable the adsorption is generally 119899 lt 1 1119899and log119870
119865are the slope and intercept respectively given by
8 Journal of Engineering
0
05
1
15
2
25
0 05 1 15 2
log q
e
log Ce
R-1R-2
Figure 9 Freundlich adsorption isotherms
plotting log 119902119890against log119862
119890 The Freundlich plot (Figure 9)
gave a slope less than unity indicating the nonlinear sorptionbehavior with U(VI) in the concentration range studiedThe observed values of 119870
119865of R-1 and R-2 were found
to be 305 and 2649 (mg gminus1) The values of equilibriumsorption capacity and correlation coefficients of Langmuirequation (119876max) are more consistent with the experimentaldata than Freundlich isothermmodelTherefore the sorptionreaction is more favorable by Langmuir model confirmingthe monolayer coverage of uranium onto the amine resins
(3) Temkinrsquos Model The derivation of the Temkin isothermassumes that the fall in the heat of sorption is linear ratherthan logarithmic as implied in the Freundlich equation [1516] The linear form of Temkin isotherm is given by thefollowing equation
119902119890=119877119879
119887ln119860119879+119877119879
119887ln119862119890
119861 =119877119879
119887
119902119890= 119861 ln119860
119879+ 119861 ln119862
119890
(7)
where 119860119879is Temkin isotherm equilibrium binding constant
(Lg) 119887 is Temkin isotherm constant 119877 is universal gasconstant (8314 JmolK) 119879 is temperature at 298K and 119861is constant related to heat of sorption (Jmol) where 119902
119890
(mg gminus1) and 119862119890(mg Lminus1) are the equilibrium concentrations
of U(VI) in the solid and liquid phase respectively Plotting119902119890versus ln119862
119890(Figure 10) should give a straight line if the
adsorption energy decreases linearly with increasing surfacecoverage According to the given relation of 119902
119890versus ln119862
119890
the estimated 119861 values of R-1 and R-2 were 5127ndash5414 Jmolthat indicate the favorability of the chemical adsorptionprocess
341 Dubinin-Radushkevich Isotherm Model The Dubinin-Radushkevich (D-R) isotherm model is more general thanthe Langmuir isotherm as its deviation is not based on ideal
0
60
120
180
0 1 2 3 4 5
qe
ln Ce
R-1R-2
Figure 10 Temkin adsorption isotherms
assumptions such as equipotential of sorption sites absenceof steric hindrances between sorbed and incoming particlesand surface homogeneity onmicroscopic levelThis isothermmodel is a temperature-dependentmodel used to estimate thecharacteristic porosity in addition to the apparent energy ofadsorption as well as expressing the adsorption mechanism[15 17] The model is represented by the following equations
119902119890= (119902119904) exp(minus119870ad (119877119879 ln [1 +
1
119862119890
])
2
)
120576 = 119877119879 ln [1 + 1
119862119890
]
119902119890= (119902119904) exp (minus119870ad120576
2)
(8)
where 119902119890is the amount of adsorbate in the adsorbent at
equilibrium (mgg) 119902119904is the theoretical isotherm saturation
capacity (mgg)119870ad is the D-R isotherm constant (mol2kJ2)related to free energy of sorption 120576 is the D-R isothermconstant 119877 represents the gas constant (8314 Jmol K) 119879 isabsolute temperature (K) and 119862
119890is adsorbate equilibrium
concentration (mgL) The linearity of D-R isotherm modelis represented by the following equation
ln 119902119890= ln 119902
119904minus 119870ad120576
2 (9)
A plot of ln 119902119890versus 1205762 yielded straight lines indicating a
good fit of the isotherm to the experimental data (Figure 11)and the values of 119902
119904and119870ad for D-R isothermwere calculated
(Table 3) 119902119904and 1198772 values were observed that this isotherm
also gave very good description of the sorption process Thehigh values of 119902
119904show high sorption capacity The approach
was usually applied to distinguish the physical and chemicaladsorption of metal ions with its mean free energy permolecule of adsorbate The apparent energy (119864 = KJmol2) ofadsorption can be computed calculated using the followingrelation
119864 = [1
radic2119870ad] (10)
Journal of Engineering 9
3
4
5
6
0 20000 40000 60000
R-1R-2
ln q e
1205762
Figure 11 Dubinin-Radushkevich isotherm model
0
25
50
75
100
0
50
100
150
200
250
0 05 1 15
Adso
rptio
n ca
paci
ty (m
gg)
Solidliquid (mgmL)
Adso
rptio
n effi
cien
cy (
)
R-1 (mgg)R-2 (mgg)R-1 ()R-2 ()
Figure 12 The effect of the solidliquid ratio on the adsorptionefficiency
The values of the apparent energy of adsorption alsodepict chemisorption process
35 SolidLiquid Ratio The effect of the solidliquid ratio onthe adsorption efficiency of the studied resins was achievedusing variable amounts of R-1 and R-2 resins (0025 to 0125 g)in 100mL of the adsorption medium and the results wereshowed in Figure 12 The adsorption efficiency of the resinsincreased with increasing their dose while the adsorptioncapacities decreased This result is reasonable if we considerthat as the higher resin dose in the solution as the higheravailability of active sites for metal ion adsorption
36 Resin Regeneration For desorption studies 05 g of theuranium loaded dry resin with uranium was gently washedwith distilled water to remove any unabsorbed metal ionsand then shaken with 100mL of 01M HNO
3for 30min
and finally the uranium concentration was determined in thefiltrate All the experiments were performed in duplicate withexperimental error plusmn05ndash2 After the uranium elution theresins were regenerated by washing with 1M NaOH solutionfollowed by washing with distilled water hence the resinbecame regenerated and ready for the next use Regenerationefficiency was found to be about 90ndash96 for two resins over3 cycles
It is worth mentioning that using of the eluted resinswithout alkalinewashing failed to adsorbmore uranium ionswhich can be ascribed to the protonation of the amino activegroups that prevent the U(VI) ions adsorption Accordinglytreatment with the alkaline solution converted these proto-nated groups into free ones which have the affinity towardsthe U(VI) ions
37 Application of the Studied Resins for Granite SamplesThree granite rock samples were collected from Gabal Gattarpluton located inNorth EasternDesert of EgyptThe sampleswere crushed and ground to minus200 mesh size and analyzed byconventional wet chemical techniques for their major oxidecompositions as well as by XRF for some trace elements Thechemical analysis of the studied granitic samples is given inTable 5 The granitic samples contain high concentration ofFe2O3(t) Rb Y Nb U and Th and low concentration of Sr
and Ba compared with similar Egyptian granitesFor thework purpose the uranium content in the granitic
samples was selectively leached using nitric acid solution(2M) for 6 hours at 60∘C The reacted slurry was filteredand washed with hot water The obtained filtrate was treatedwith R-1 and R-2 for the uranium separation The uptakeresults of U(VI) ions (Table 6) showed that both the resinsdisplayed higher removal efficiency towards U(VI) relative toother metal ions present in sample solution
4 Conclusion
Magnetic glycidyl methacrylate resin particles with nano-magnetite core and glycidyl methacrylateNN1015840-methylene-bis-acrylamide resin shell were prepared and modified withDA and TA The studied resins showed high adsorptioncapacities towards uranium ions reached 92 and 158mggfor R-1 and R-2 respectively The results revealed that thepseudo-second-order sorption is the predominant mech-anism The amount of U(VI) adsorbed per unit mass ofall resins increased as temperature increased showing theendothermic nature of the sorption process The experimen-tal results from equilibrium experiences were computed byseveral adsorption isotherm models Langmuir FreundlichTemkin and Dubinin-Radushkevich isotherm model Theresults showed that the sorption reaction is more favorableby Langmuir model confirming the monolayer coverage ofuraniumonto the amine resins and indicate the favorability ofthe chemical adsorption processThe positive heat of adsorp-tion indicates that the adsorption process is endothermicThe
10 Journal of Engineering
Table 5 Chemical analysis of granitic samples
Sample Majorconstituent Trace
constituentConcentration
ppm
1
SiO2
735 U 4000AL2O3
128 Th 300Fe2O3
25 Rare earth 270CaO 13 Rb 225Na2O 26 Zr 197
MgO 05 Y 126K2O 24
2
SiO2
735 U 3200AL2O3
138 Th 190Fe2O3
36 Rare earth 270CaO 14 Rb mdashNa2O 06 Zr 400
MgO 05 Y 197K2O 24
3
SiO2
725 U 2700AL2O3
128 Th 260Fe2O3
25 Rare earth 250CaO 13 Rb 437Na2O 39 Zr 284
MgO 05 Y 135K2O 34
Table 6 Results of treatment of the granite samples with the studiedresins
Resin Metal ion Removal efficiency ()Sample 1 Sample 2 Sample 3
R-1U(VI) 93 93 928Fe(III) 26 25 26RE2O3
15 15 15
R-2U(VI) 995 992 99Fe(III) 31 31 31RE2O3
55 80 85
positive value of Δ119878∘ points to increasing of the randomnessdegree at the resinsolution interface during the progress ofsorption process The negative values of Δ119866∘ values confirmthe spontaneous nature of the sorption process
Finally it can be concluded that
(1) the prepared magnetite-cored resins have advantagetoward the filtration process where the magnetiteparticles impart the magnetic properties to the beadsthat allow rapid and easy separation of beads by theapplication of an external magnetic field avoidingsome technical problems arising due to using thetraditional filter papers
(2) the magnetite core allows more spreading of theactive group on the surface of resin particles thatenhance the adsorption efficiency comparing to othernonmagnetite core resins [10]
(3) the prepared resins are recommended as effectiveadsorbate materials regarding separation of uraniumions from their bearing solutions particularly in thepresence of other competitive metal ions
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] O Philippova A Barabanova V Molchanov and A KhokhlovldquoMagnetic polymer beads recent trends and developments insynthetic design and applicationsrdquo European Polymer Journalvol 47 no 4 pp 542ndash559 2011
[2] Q Yuan and R A Williams ldquoLarge scale manufacture ofmagnetic polymer particles using membranes and microfluidicdevicesrdquo China Particuology vol 5 no 1-2 pp 26ndash42 2007
[3] C-Y Chen C-L Chiang and P-C Huang ldquoAdsorptions ofheavy metal ions by a magnetic chelating resin containinghydroxy and iminodiacetate groupsrdquo Separation and Purifica-tion Technology vol 50 no 1 pp 15ndash21 2006
[4] D Horak B Rittich and A Spanova ldquoCarboxyl-functionalizedmagnetic microparticle carrier for isolation and identificationof DNA in dairy productsrdquo Journal of Magnetism and MagneticMaterials vol 311 no 1 pp 249ndash254 2007
[5] AAAtia AMDonia andA E Shahin ldquoStudies on the uptakebehavior of a magnetic Co
3O4-containing resin for Ni(II)
Cu(II) andHg(II) from their aqueous solutionsrdquo Separation andPurification Technology vol 46 no 3 pp 208ndash213 2005
[6] A M Donia A A Atia H A El-Boraey and D H MabroukldquoAdsorption of Ag(I) on glycidyl methacrylateNN1015840-methylenebis-acrylamide chelating resins with embedded iron oxiderdquoSeparation and Purification Technology vol 48 no 3 pp 281ndash287 2006
[7] A M Donia A A Atia H A El-Boraey and D H MabroukldquoUptake studies of copper(II) on glycidyl methacrylate chelat-ing resin containing Fe
2O3particlesrdquo Separation and Purifica-
tion Technology vol 49 no 1 pp 64ndash70 2006[8] A M Donia A A Atia and K Z Elwakeel ldquoSelective sepa-
ration of mercury(II) using magnetic chitosan resin modifiedwith Schiff rsquos base derived from thiourea and glutaraldehyderdquoJournal of Hazardous Materials vol 151 no 2-3 pp 372ndash3792008
[9] K Z Elwakeel and A A Atia ldquoUptake of U(VI) from aqueousmedia by magnetic Schiff rsquos base chitosan compositerdquo Journal ofCleaner Production vol 70 pp 292ndash302 2014
[10] A M Donia A A Atia E M M Moussa A M El-Sherifand M O Abd El-Magied ldquoRemoval of uranium(VI) fromaqueous solutions using glycidyl methacrylate chelating resinsrdquoHydrometallurgy vol 95 no 3-4 pp 183ndash189 2009
[11] Z Marczenko Separation and Spectrophotometric Determina-tion of Elements Ellis Harwood Chichester UK 1986
[12] S A Sadeek M A El-Sayed M M Amine and M O Abd El-Magied ldquoA chelating resin containing trihydroxybenzoic acidas the functional group synthesis and adsorption behavior forTh(IV) and U(VI) ionsrdquo Journal of Radioanalytical and NuclearChemistry vol 299 no 3 pp 1299ndash1306 2014
[13] W Dong and S C Brooks ldquoDetermination of the formationconstants of ternary complexes of uranyl and carbonate with
Journal of Engineering 11
alkaline earth metals (Mg2+ Ca2+ Sr2+ and Ba2+) using anionexchangemethodrdquoEnvironmental ScienceampTechnology vol 40no 15 pp 4689ndash4695 2006
[14] C Xiong X Liu and C Yao ldquoEffect of pH on sorptionfor RE(III) and sorption behaviors of Sm(III) by D152 resinrdquoJournal of Rare Earths vol 26 no 6 pp 851ndash856 2008
[15] A O Dada A P Olalekan A M Olatunya and O DadaldquoLangmuir Freundlich Temkin and Dubinin-Radushkevichisotherms studies of equilibrium sorption of Zn2+ unto phos-phoric acid modified rice huskrdquo Journal of Applied Chemistryvol 3 no 1 pp 38ndash45 2012
[16] V P Mpofu J Addai-Mensah and J Ralston ldquoTemperatureinfluence of nonionic polyethylene oxide and anionic polyacry-lamide on flocculation and dewatering behavior of kaolinitedispersionsrdquo Journal of Colloid and Interface Science vol 271no 1 pp 145ndash156 2004
[17] A U Itodo andHU Itodo ldquoSorption energies estimation usingDubinin-Radushkevich andTemkin adsorption isothermsrdquo LifeScience Journal vol 7 no 4 pp 31ndash39 2010
[18] K Dev R Pathak and G N Rao ldquoSorption behaviour oflanthanum(III) neodymium(III) terbium(III) thorium(IV)and uranium(VI) on Amberlite XAD-4 resin functionalizedwith bicine ligandsrdquo Talanta vol 48 no 3 pp 579ndash584 1999
[19] V K Jain A Handa S S Sait P Shrivastav and Y K AgrawalldquoPre-concentration separation and trace determination of lan-thanum(III) cerium(III) thorium(IV) and uranium(VI) onpolymer supported o-vanillinsemicarbazonerdquo Analytica Chim-ica Acta vol 429 no 2 pp 237ndash246 2001
[20] M Nogami I M Ismail M Yamaguchi and K SuzukildquoSynthesis characterization and some adsorption properties ofTMMA chelating resinrdquo Journal of Solid State Chemistry vol171 no 1-2 pp 353ndash357 2003
[21] P Metilda K Sanghamitra J M Gladis G R K Naiduand T Prasada Rao ldquoAmberlite XAD-4 functionalized withsuccinic acid for the solid phase extractive preconcentrationand separation of uranium(VI)rdquo Talanta vol 65 no 1 pp 192ndash200 2005
[22] DH Phillips B GuD BWatson andC S Parmele ldquoUraniumremoval from contaminated groundwater by synthetic resinsrdquoWater Research vol 42 no 1-2 pp 260ndash268 2008
[23] Y Jung S Kim S-J Park and J M Kim ldquoApplication ofpolymer-modified nanoporous silica to adsorbents of uranylionsrdquo Colloids and Surfaces A vol 313-314 pp 162ndash166 2008
[24] G Tian J Geng Y Jin et al ldquoSorption of uranium(VI) usingoxime-grafted ordered mesoporous carbon CMK-5rdquo Journal ofHazardous Materials vol 190 no 1ndash3 pp 442ndash450 2011
[25] T S Anirudhan J Nima and P L Divya ldquoAdsorption and sep-aration behavior of uranium(VI) by 4-vinylpyridine-grafted-vinyltriethoxysilane-cellulose ion imprinted polymerrdquo Journalof Environmental Chemical Engineering vol 3 no 2 pp 1267ndash1276 2015
[26] N T Tavengwa E Cukrowska and L Chimuka ldquoSynthesis ofbulk ion-imprinted polymers (IIPs) embedded with oleic acidcoated Fe
3O4for selective extraction of hexavalent uraniumrdquo
Water SA vol 40 no 4 pp 623ndash630 2014[27] M Solgy M Taghizadeh and D Ghoddocynejad ldquoAdsorption
of uranium(VI) from sulphate solutions using Amberlite IRA-402 resin equilibrium kinetics and thermodynamics studyrdquoAnnals of Nuclear Energy vol 75 pp 132ndash138 2015
[28] J Li X Yang C Bai et al ldquoA novel benzimidazole-functionalized 2-D COF material synthesis and application as
a selective solid-phase extractant for separation of uraniumrdquoJournal of Colloid and Interface Science vol 437 pp 211ndash2182015
[29] N T Tavengwa E Cukrowska and L Chimuka ldquoSelectiveadsorption of uranium (VI) on NaHCO
3leached composite
120574-methacryloxypropyltrimethoxysilane coated magnetic ion-imprinted polymers prepared by precipitation polymerizationrdquoSouth African Journal of Chemistry vol 68 pp 61ndash68 2015
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4 Journal of Engineering
Figure 2 The scanning electron microscopy images of the studied resins before and after uranium sorption
Table 1 Adsorption capacities of uranium by different adsorbents
Chelating resins 119902119890(mgg) Reference
Modified polystyrene 595 [18]Calix[4]resorcinarene 640 [19]Tetramethylmalonamide (TMMA) 1190 [20]Amberlite XAD-4-succinic acid 123 [21]Modified Dowextrade 12K 498 [22]Nanoporous silica 294 [23]Mesoporous carbon CMK-5 652 [24]4-Vinylpyridine 134 [25]Salicylaldoxime and 4-vinylpyridine 12 [26]IRA-402 resin 213 [27]Covalent organic frameworks 81 [28]Salicylaldoxime and 4-vinylpyridine 115 [29]R-1 92 This workR-2 158 This work
the investigated resins were characterized by higher 119902119890value
relative to that reported by othersThe surface morphology of the studied resins before
and after uranium sorption was studied by SEM analysis(Figure 2) The surface morphology of the uranium loadedresins showed a large particle with close-packed plane
surface which could be assigned to the sorption of uraniumions onto the surface of the studied loaded resins
The observed lower sorption of U(VI) ions in higheracidic medium may be attributed to the partial protonationof the amino groups to give positively charged protonatedamino groups that do not promote U(VI) adsorption due torepulsion force
Hydrolysis of U(VI) ions was observed to begin at pH gt 5and various positively charged hydrolyzed uranium speciesexist ([(UO
2)3(OH)4]2+ [(UO
2)2OH]3+ [(UO
2)3(OH)]5+
and [(UO2)4(OH)]7+) which have lower affinity to R-1 and R-
2 Also negatively charged uranium species ([UO2(OH)4]2minus
and [(UO2)3(OH)7]minus) were found at higher pH values which
cannot react with R-1 and R-2 [10ndash12]The values of the experimentalmaximum sorption capac-
ities were 92 and 158mgg for R-1 and R-2 The values of themaximum sorption of resins are related to their amine groupcontent of 55 and 81mmolg for R-1 and R-2 The higherconcentration of amine active sites in case of R-1 and R-2relative to the free magnetite ones (38 and 54mmolg) mayindicate the formation of extended thin film of the resin overthe metal oxide particles This would allow the active siteshidden within the core of the resin matrix to become moreexposed for interaction with metal ions [10]
The mechanism of interaction between U(VI) ions andamine active sites on R-1 and R-2 resins may be relatedto their coordination modes U(VI) ions can coordinate by
Journal of Engineering 5
0
60
120
180
0 30 60 90Time (min)
qt
(mg
g)
R-1R-2
Figure 3 Effect of time on adsorption process
four five or six amine active sites of R-1 and R-2 resins[10] The molar ratios of sorbed U(VI) ions and resins activesites are 1 4 1 5 and 1 6 The experimental maximumsorption capacities of 92mgg (039mmolg) and 158mgg(066mmolg) for R-1 and R-2 are closer to the theoreticalsorption value corresponding to the molar ratio of 1 6 (092and 14mmolg for R-1 and R-2) The observed differencesbetween the experimental and expected sorption capacitiesvalues may be attributed to the nonaccessibility of all activesites for coordination with U(VI)This behavior confirms theeffect of textural properties on the nature of binding as wellas the sorption capacity
32 Effect of Contact Time and Adsorption Kinetics Sorptionof U(VI) on both R-1 and R-2 resins was investigated as afunction of contact time and the data obtained are shownin Figure 3 Uranium sorption increased as the contact timeincreased and reached its maximum sorption capacities at45 and 30min on R-1 and R-2 respectively To verify theorder of the adsorption process pseudo-first-order kineticsand pseudo-second-order kineticsmodels [10 12] were testedaccording to the following equations
Pseudo first order log (119902119890minus 119902119905) = log (119902
1st) minus1198961
2303119905
Pseudo second order 119905119902119905
=1
119896211990222nd+1
119902119890
119905
(1)
where 119902119890is the maximum experimental sorption capacity
(mg gminus1) 119902119905is the experimental sorption capacity at time (119905)
(mg gminus1) 1199021st is the calculated sorption capacity according
to pseudo-first-order model (mg gminus1) 1198961is the rate constant
of pseudo-first-order (minminus1) 1199022nd is the calculated sorption
capacity according to pseudo-second-order model (mg gminus1)and 119896
2is the rate constant of pseudo-second-order (minminus1)
Values of 1198961and 119902
1st were calculated from the slope andintercept values of plotting log(119902
119890minus 119902119905) versus (119905) as shown in
Figure 4 The plot of 119905119902119905versus (119905) (Figure 5) gives a straight
line with slope and intercept equal to 1119902119890and 1119896
2119902119890
2
05
1
15
2
0 10 20 30 40Time (min)
R-1R-2
log(qeminusqt)
Figure 4 The pseudo-first-order kinetics model
0
02
04
06
0 20 40 60Time (min)
tqt
R-1R-2
Figure 5 The pseudo-second-order kinetics model
respectivelyThe calculated values of 1198961 1199021st 1198962 and 1199022nd were
reported in Table 2The obtained data (119902 and 1198772) proved that the adsorption
rate is likely to be controlled by pseudo-second-order kineticmodel rather than the pseudo-first-order kinetic modelThe rate of adsorption is less controlled by intraparticlediffusion due to the bulky size of U(VI) ions that implies thatadsorption of U(VI) is dependent on concentration of boththe metal ions and active sites concentrations
33 Effect of Adsorption Temperature The temperature effecton U(VI) adsorption was tested as function of 4 temperaturedegrees (298 303 313 and 323) (Figure 6) An increase intemperature resulting in an increase in the amount of U(VI)adsorbed per unit mass of all resins might be attributed tothe change in surface properties of the sorbent and solubilityof the solute species with endothermic nature of the sorptionprocess
34 Adsorption Isotherms A relation between the amount ofadsorbate adsorbed on a given surface at constant temper-ature and the equilibrium concentration of the substrate in
6 Journal of Engineering
Table 2 Kinetic data for adsorption of U(VI) on R-1 and R-2 resins
Resin Experimental Pseudo-first-order kinetics Pseudo-second-order kinetics119902119890(mgg) 119902
1st (mgg) 1198961(minminus1) 119877
21199022nd (mgg) 119896
2(minminus1) 119877
2
R-1 92 5117 006 0942 100 0003 0997R-2 158 7413 007 0935 200 0002 0993
0
40
80
120
0 30 60 90
R-1
0
60
120
180
0 15 30 45
R-2
Ce (mgL)
qe
(mg
g)
Ce (mgL)
qe
(mg
g)298K303K
313K323K
298K303K
313K323K
Figure 6 Effect of adsorption temperature on adsorption process
0
03
06
09
0 20 40 60
R-1
0
005
01
015
0 10 20 30
R-2
Ce (mgL) Ce (mgL)
Ceq
e(g
L)
Ceq
e(g
L)
298K303K
313K323K
298K303K
313K323K
Figure 7 Langmuir adsorption isotherm
contact with the adsorbent is known as adsorption isothermAdsorption isotherms depend on certain parameters whosevalues express the surface properties and the affinity of thesorbent We can compute experimental results from equilib-rium experiences by several adsorption isotherm models
(1) Langmuir Model The most widely used isotherm equa-tion for modeling equilibrium data is the Langmuir modelLangmuir derived a relation between adsorbed material andits equilibrium concentration [10 13 14] The linear form ofLangmuir equation is given by
119862119890
119902119890
=119862119890
119902max+
1
119870119871119876max
(2)
where 119862119890is the equilibrium concentration of ions in solution
(mg Lminus1) 119902119890is the amount adsorbed at 119862
119890(mg gminus1) 119876max
is the maximum adsorption capacity (mg gminus1) and 119870119871is
the binding constant which is related to the energy ofadsorption (Lmgminus1) Plotting 119862
119890119902119890against 119862
119890(Figure 7)
gives a straight line with slope and intercept equal to 1119876maxand 1119870
119871119876max respectively The values of 119870
119871and 119876max at
different temperatures are reported in Table 3 The values of119870119871and119876max increase as the temperature increases Increasing
of119870119871value with increasing of temperature implies the strong
binding between U(VI) ions and the active sites at elevatedtemperatures
The thermodynamic parameters such as enthalpy change(Δ119867∘) and entropy change (Δ119878∘) corresponding to U(IV)sorption on the studied resins were calculated using VanrsquotHoff equation [10]
ln119870119871=Δ119878∘
119877minusΔ119867∘
119877119879 (3)
where 119877 is the universal gas constant (8314 Jmolminus1sdotKminus1)and 119879 is the absolute temperature (Kelvin) Plotting ln 119870
119871
against 1119879 (Figure 8) gives a straight line with interceptand slope equal to Δ119878∘119877 and minusΔ119867∘119877 respectively Thevalues of Δ119878∘ and Δ119867∘ were calculated and reported in
Journal of Engineering 7
Table 3 Isotherms parameters for the sorption of U(VI) ions
Resin Experimental 119902119890(mgg) Langmuir parameters Freundlich parameters
119870119871(Lmol) 119876Max (mgg) 119877
2119899 119870
119891(mgg) 119877
2
R-1 92 0026 100 0981 1247 3083 09907R-2 158 0133 16667 0977 1887 26485 08233
Resin Temkin parameters D-R parameters119861 (Jmol) 119860
119879(Lg) 119877
2119902119904(mgg) 119870ad (mol2kJ2) 119864 (kJmol2) 119877
2
R-1 5414 0080 0871 9454 9 times 10minus5 7454 085R-2 5127 0681 0934 1697 5 times 10minus5 100 0923
Table 4 Thermodynamic parameters for adsorption of U(VI) by R-1 and R-2 at different temperatures
Resin Temp (Kelvin) Thermodynamic parametersΔ119867∘ (kJmol) Δ119878
∘ (KJmolsdotK) 119879Δ119878∘ (kJmol) Δ119866
∘ (kJmol)
R-1
298
27328 016445
4901 minus2168303 4983 minus225313 5147 minus2414323 5312 minus2579
R-2
298
26064 01741
5188 minus2582303 5275 minus2669313 5449 minus2843323 5623 minus3017
Table 4 The positive Δ119867∘ value indicates that the adsorptionprocess is endothermic The positive value of Δ119878∘ maybe explained by the increased degree of randomness atthe resinsolution interface during the progress of sorptionprocess This phenomenon could be ascribed to liberation offree water molecules as a result of the substitution reactionbetween chelating amine active sites and hydrated U(VI)ion The Gibbs free energy of adsorption reaction (Δ119866∘) wascalculated using the following relation [10]
Δ119866∘= Δ119867
∘minus 119879Δ119878
∘ (4)
The values of Δ119866∘ values (Table 4) confirm the spon-taneous nature and feasibility of the sorption process andthe favorable U(VI) sorption takes place with increasing oftemperature
The suitability of the resins towards metal ions is throughthe values of separation factor constant (119877
119871) where 119877
119871gt 1
(unsuitable) 119877119871= 1 (linear) 0 lt 119877
119871lt 1 (suitable) 119877
119871= 0
(irreversible) [10] The value of 119877119871could be calculated from
(4)
119877119871=
1
1 + 119870119871119862119900
(5)
where 119862119900is the initial concentration of U(VI) ions (mM)
The values of 119877119871for sorption of U(VI) on R-1 and R-2
resins at different temperature were calculated and foundto lie between 0041 and 0281 indicating their suitability asadsorbents for U(VI)
(2) Freundlich Model The Freundlich isotherm model [1516] is an empirical relationship that describes the sorptionof solutes on a solid surface assuming that different sites
8
9
10
11
12
00031 00033 00035
1T (Kminus1)
ln K
L
R-1R-2
Figure 8 Vanrsquot Hoff plots for the adsorption process
with several sorption energies are involved (the surface ofadsorbent is heterogeneous)This isothermmodel is given by(3)
log 119902119890= log119870
119865+log119862119890
119899 (6)
where 119902119890(mg gminus1) and 119862
119890(mg Lminus1) are the equilibrium
concentrations of U(VI) in the solid and liquid phaserespectively 119870
119865(mg gminus1) and n are characteristic constants
related to the relative sorption capacity of the sorbent and theintensity of sorption respectively The higher the 1119899 valueis the more favorable the adsorption is generally 119899 lt 1 1119899and log119870
119865are the slope and intercept respectively given by
8 Journal of Engineering
0
05
1
15
2
25
0 05 1 15 2
log q
e
log Ce
R-1R-2
Figure 9 Freundlich adsorption isotherms
plotting log 119902119890against log119862
119890 The Freundlich plot (Figure 9)
gave a slope less than unity indicating the nonlinear sorptionbehavior with U(VI) in the concentration range studiedThe observed values of 119870
119865of R-1 and R-2 were found
to be 305 and 2649 (mg gminus1) The values of equilibriumsorption capacity and correlation coefficients of Langmuirequation (119876max) are more consistent with the experimentaldata than Freundlich isothermmodelTherefore the sorptionreaction is more favorable by Langmuir model confirmingthe monolayer coverage of uranium onto the amine resins
(3) Temkinrsquos Model The derivation of the Temkin isothermassumes that the fall in the heat of sorption is linear ratherthan logarithmic as implied in the Freundlich equation [1516] The linear form of Temkin isotherm is given by thefollowing equation
119902119890=119877119879
119887ln119860119879+119877119879
119887ln119862119890
119861 =119877119879
119887
119902119890= 119861 ln119860
119879+ 119861 ln119862
119890
(7)
where 119860119879is Temkin isotherm equilibrium binding constant
(Lg) 119887 is Temkin isotherm constant 119877 is universal gasconstant (8314 JmolK) 119879 is temperature at 298K and 119861is constant related to heat of sorption (Jmol) where 119902
119890
(mg gminus1) and 119862119890(mg Lminus1) are the equilibrium concentrations
of U(VI) in the solid and liquid phase respectively Plotting119902119890versus ln119862
119890(Figure 10) should give a straight line if the
adsorption energy decreases linearly with increasing surfacecoverage According to the given relation of 119902
119890versus ln119862
119890
the estimated 119861 values of R-1 and R-2 were 5127ndash5414 Jmolthat indicate the favorability of the chemical adsorptionprocess
341 Dubinin-Radushkevich Isotherm Model The Dubinin-Radushkevich (D-R) isotherm model is more general thanthe Langmuir isotherm as its deviation is not based on ideal
0
60
120
180
0 1 2 3 4 5
qe
ln Ce
R-1R-2
Figure 10 Temkin adsorption isotherms
assumptions such as equipotential of sorption sites absenceof steric hindrances between sorbed and incoming particlesand surface homogeneity onmicroscopic levelThis isothermmodel is a temperature-dependentmodel used to estimate thecharacteristic porosity in addition to the apparent energy ofadsorption as well as expressing the adsorption mechanism[15 17] The model is represented by the following equations
119902119890= (119902119904) exp(minus119870ad (119877119879 ln [1 +
1
119862119890
])
2
)
120576 = 119877119879 ln [1 + 1
119862119890
]
119902119890= (119902119904) exp (minus119870ad120576
2)
(8)
where 119902119890is the amount of adsorbate in the adsorbent at
equilibrium (mgg) 119902119904is the theoretical isotherm saturation
capacity (mgg)119870ad is the D-R isotherm constant (mol2kJ2)related to free energy of sorption 120576 is the D-R isothermconstant 119877 represents the gas constant (8314 Jmol K) 119879 isabsolute temperature (K) and 119862
119890is adsorbate equilibrium
concentration (mgL) The linearity of D-R isotherm modelis represented by the following equation
ln 119902119890= ln 119902
119904minus 119870ad120576
2 (9)
A plot of ln 119902119890versus 1205762 yielded straight lines indicating a
good fit of the isotherm to the experimental data (Figure 11)and the values of 119902
119904and119870ad for D-R isothermwere calculated
(Table 3) 119902119904and 1198772 values were observed that this isotherm
also gave very good description of the sorption process Thehigh values of 119902
119904show high sorption capacity The approach
was usually applied to distinguish the physical and chemicaladsorption of metal ions with its mean free energy permolecule of adsorbate The apparent energy (119864 = KJmol2) ofadsorption can be computed calculated using the followingrelation
119864 = [1
radic2119870ad] (10)
Journal of Engineering 9
3
4
5
6
0 20000 40000 60000
R-1R-2
ln q e
1205762
Figure 11 Dubinin-Radushkevich isotherm model
0
25
50
75
100
0
50
100
150
200
250
0 05 1 15
Adso
rptio
n ca
paci
ty (m
gg)
Solidliquid (mgmL)
Adso
rptio
n effi
cien
cy (
)
R-1 (mgg)R-2 (mgg)R-1 ()R-2 ()
Figure 12 The effect of the solidliquid ratio on the adsorptionefficiency
The values of the apparent energy of adsorption alsodepict chemisorption process
35 SolidLiquid Ratio The effect of the solidliquid ratio onthe adsorption efficiency of the studied resins was achievedusing variable amounts of R-1 and R-2 resins (0025 to 0125 g)in 100mL of the adsorption medium and the results wereshowed in Figure 12 The adsorption efficiency of the resinsincreased with increasing their dose while the adsorptioncapacities decreased This result is reasonable if we considerthat as the higher resin dose in the solution as the higheravailability of active sites for metal ion adsorption
36 Resin Regeneration For desorption studies 05 g of theuranium loaded dry resin with uranium was gently washedwith distilled water to remove any unabsorbed metal ionsand then shaken with 100mL of 01M HNO
3for 30min
and finally the uranium concentration was determined in thefiltrate All the experiments were performed in duplicate withexperimental error plusmn05ndash2 After the uranium elution theresins were regenerated by washing with 1M NaOH solutionfollowed by washing with distilled water hence the resinbecame regenerated and ready for the next use Regenerationefficiency was found to be about 90ndash96 for two resins over3 cycles
It is worth mentioning that using of the eluted resinswithout alkalinewashing failed to adsorbmore uranium ionswhich can be ascribed to the protonation of the amino activegroups that prevent the U(VI) ions adsorption Accordinglytreatment with the alkaline solution converted these proto-nated groups into free ones which have the affinity towardsthe U(VI) ions
37 Application of the Studied Resins for Granite SamplesThree granite rock samples were collected from Gabal Gattarpluton located inNorth EasternDesert of EgyptThe sampleswere crushed and ground to minus200 mesh size and analyzed byconventional wet chemical techniques for their major oxidecompositions as well as by XRF for some trace elements Thechemical analysis of the studied granitic samples is given inTable 5 The granitic samples contain high concentration ofFe2O3(t) Rb Y Nb U and Th and low concentration of Sr
and Ba compared with similar Egyptian granitesFor thework purpose the uranium content in the granitic
samples was selectively leached using nitric acid solution(2M) for 6 hours at 60∘C The reacted slurry was filteredand washed with hot water The obtained filtrate was treatedwith R-1 and R-2 for the uranium separation The uptakeresults of U(VI) ions (Table 6) showed that both the resinsdisplayed higher removal efficiency towards U(VI) relative toother metal ions present in sample solution
4 Conclusion
Magnetic glycidyl methacrylate resin particles with nano-magnetite core and glycidyl methacrylateNN1015840-methylene-bis-acrylamide resin shell were prepared and modified withDA and TA The studied resins showed high adsorptioncapacities towards uranium ions reached 92 and 158mggfor R-1 and R-2 respectively The results revealed that thepseudo-second-order sorption is the predominant mech-anism The amount of U(VI) adsorbed per unit mass ofall resins increased as temperature increased showing theendothermic nature of the sorption process The experimen-tal results from equilibrium experiences were computed byseveral adsorption isotherm models Langmuir FreundlichTemkin and Dubinin-Radushkevich isotherm model Theresults showed that the sorption reaction is more favorableby Langmuir model confirming the monolayer coverage ofuraniumonto the amine resins and indicate the favorability ofthe chemical adsorption processThe positive heat of adsorp-tion indicates that the adsorption process is endothermicThe
10 Journal of Engineering
Table 5 Chemical analysis of granitic samples
Sample Majorconstituent Trace
constituentConcentration
ppm
1
SiO2
735 U 4000AL2O3
128 Th 300Fe2O3
25 Rare earth 270CaO 13 Rb 225Na2O 26 Zr 197
MgO 05 Y 126K2O 24
2
SiO2
735 U 3200AL2O3
138 Th 190Fe2O3
36 Rare earth 270CaO 14 Rb mdashNa2O 06 Zr 400
MgO 05 Y 197K2O 24
3
SiO2
725 U 2700AL2O3
128 Th 260Fe2O3
25 Rare earth 250CaO 13 Rb 437Na2O 39 Zr 284
MgO 05 Y 135K2O 34
Table 6 Results of treatment of the granite samples with the studiedresins
Resin Metal ion Removal efficiency ()Sample 1 Sample 2 Sample 3
R-1U(VI) 93 93 928Fe(III) 26 25 26RE2O3
15 15 15
R-2U(VI) 995 992 99Fe(III) 31 31 31RE2O3
55 80 85
positive value of Δ119878∘ points to increasing of the randomnessdegree at the resinsolution interface during the progress ofsorption process The negative values of Δ119866∘ values confirmthe spontaneous nature of the sorption process
Finally it can be concluded that
(1) the prepared magnetite-cored resins have advantagetoward the filtration process where the magnetiteparticles impart the magnetic properties to the beadsthat allow rapid and easy separation of beads by theapplication of an external magnetic field avoidingsome technical problems arising due to using thetraditional filter papers
(2) the magnetite core allows more spreading of theactive group on the surface of resin particles thatenhance the adsorption efficiency comparing to othernonmagnetite core resins [10]
(3) the prepared resins are recommended as effectiveadsorbate materials regarding separation of uraniumions from their bearing solutions particularly in thepresence of other competitive metal ions
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] O Philippova A Barabanova V Molchanov and A KhokhlovldquoMagnetic polymer beads recent trends and developments insynthetic design and applicationsrdquo European Polymer Journalvol 47 no 4 pp 542ndash559 2011
[2] Q Yuan and R A Williams ldquoLarge scale manufacture ofmagnetic polymer particles using membranes and microfluidicdevicesrdquo China Particuology vol 5 no 1-2 pp 26ndash42 2007
[3] C-Y Chen C-L Chiang and P-C Huang ldquoAdsorptions ofheavy metal ions by a magnetic chelating resin containinghydroxy and iminodiacetate groupsrdquo Separation and Purifica-tion Technology vol 50 no 1 pp 15ndash21 2006
[4] D Horak B Rittich and A Spanova ldquoCarboxyl-functionalizedmagnetic microparticle carrier for isolation and identificationof DNA in dairy productsrdquo Journal of Magnetism and MagneticMaterials vol 311 no 1 pp 249ndash254 2007
[5] AAAtia AMDonia andA E Shahin ldquoStudies on the uptakebehavior of a magnetic Co
3O4-containing resin for Ni(II)
Cu(II) andHg(II) from their aqueous solutionsrdquo Separation andPurification Technology vol 46 no 3 pp 208ndash213 2005
[6] A M Donia A A Atia H A El-Boraey and D H MabroukldquoAdsorption of Ag(I) on glycidyl methacrylateNN1015840-methylenebis-acrylamide chelating resins with embedded iron oxiderdquoSeparation and Purification Technology vol 48 no 3 pp 281ndash287 2006
[7] A M Donia A A Atia H A El-Boraey and D H MabroukldquoUptake studies of copper(II) on glycidyl methacrylate chelat-ing resin containing Fe
2O3particlesrdquo Separation and Purifica-
tion Technology vol 49 no 1 pp 64ndash70 2006[8] A M Donia A A Atia and K Z Elwakeel ldquoSelective sepa-
ration of mercury(II) using magnetic chitosan resin modifiedwith Schiff rsquos base derived from thiourea and glutaraldehyderdquoJournal of Hazardous Materials vol 151 no 2-3 pp 372ndash3792008
[9] K Z Elwakeel and A A Atia ldquoUptake of U(VI) from aqueousmedia by magnetic Schiff rsquos base chitosan compositerdquo Journal ofCleaner Production vol 70 pp 292ndash302 2014
[10] A M Donia A A Atia E M M Moussa A M El-Sherifand M O Abd El-Magied ldquoRemoval of uranium(VI) fromaqueous solutions using glycidyl methacrylate chelating resinsrdquoHydrometallurgy vol 95 no 3-4 pp 183ndash189 2009
[11] Z Marczenko Separation and Spectrophotometric Determina-tion of Elements Ellis Harwood Chichester UK 1986
[12] S A Sadeek M A El-Sayed M M Amine and M O Abd El-Magied ldquoA chelating resin containing trihydroxybenzoic acidas the functional group synthesis and adsorption behavior forTh(IV) and U(VI) ionsrdquo Journal of Radioanalytical and NuclearChemistry vol 299 no 3 pp 1299ndash1306 2014
[13] W Dong and S C Brooks ldquoDetermination of the formationconstants of ternary complexes of uranyl and carbonate with
Journal of Engineering 11
alkaline earth metals (Mg2+ Ca2+ Sr2+ and Ba2+) using anionexchangemethodrdquoEnvironmental ScienceampTechnology vol 40no 15 pp 4689ndash4695 2006
[14] C Xiong X Liu and C Yao ldquoEffect of pH on sorptionfor RE(III) and sorption behaviors of Sm(III) by D152 resinrdquoJournal of Rare Earths vol 26 no 6 pp 851ndash856 2008
[15] A O Dada A P Olalekan A M Olatunya and O DadaldquoLangmuir Freundlich Temkin and Dubinin-Radushkevichisotherms studies of equilibrium sorption of Zn2+ unto phos-phoric acid modified rice huskrdquo Journal of Applied Chemistryvol 3 no 1 pp 38ndash45 2012
[16] V P Mpofu J Addai-Mensah and J Ralston ldquoTemperatureinfluence of nonionic polyethylene oxide and anionic polyacry-lamide on flocculation and dewatering behavior of kaolinitedispersionsrdquo Journal of Colloid and Interface Science vol 271no 1 pp 145ndash156 2004
[17] A U Itodo andHU Itodo ldquoSorption energies estimation usingDubinin-Radushkevich andTemkin adsorption isothermsrdquo LifeScience Journal vol 7 no 4 pp 31ndash39 2010
[18] K Dev R Pathak and G N Rao ldquoSorption behaviour oflanthanum(III) neodymium(III) terbium(III) thorium(IV)and uranium(VI) on Amberlite XAD-4 resin functionalizedwith bicine ligandsrdquo Talanta vol 48 no 3 pp 579ndash584 1999
[19] V K Jain A Handa S S Sait P Shrivastav and Y K AgrawalldquoPre-concentration separation and trace determination of lan-thanum(III) cerium(III) thorium(IV) and uranium(VI) onpolymer supported o-vanillinsemicarbazonerdquo Analytica Chim-ica Acta vol 429 no 2 pp 237ndash246 2001
[20] M Nogami I M Ismail M Yamaguchi and K SuzukildquoSynthesis characterization and some adsorption properties ofTMMA chelating resinrdquo Journal of Solid State Chemistry vol171 no 1-2 pp 353ndash357 2003
[21] P Metilda K Sanghamitra J M Gladis G R K Naiduand T Prasada Rao ldquoAmberlite XAD-4 functionalized withsuccinic acid for the solid phase extractive preconcentrationand separation of uranium(VI)rdquo Talanta vol 65 no 1 pp 192ndash200 2005
[22] DH Phillips B GuD BWatson andC S Parmele ldquoUraniumremoval from contaminated groundwater by synthetic resinsrdquoWater Research vol 42 no 1-2 pp 260ndash268 2008
[23] Y Jung S Kim S-J Park and J M Kim ldquoApplication ofpolymer-modified nanoporous silica to adsorbents of uranylionsrdquo Colloids and Surfaces A vol 313-314 pp 162ndash166 2008
[24] G Tian J Geng Y Jin et al ldquoSorption of uranium(VI) usingoxime-grafted ordered mesoporous carbon CMK-5rdquo Journal ofHazardous Materials vol 190 no 1ndash3 pp 442ndash450 2011
[25] T S Anirudhan J Nima and P L Divya ldquoAdsorption and sep-aration behavior of uranium(VI) by 4-vinylpyridine-grafted-vinyltriethoxysilane-cellulose ion imprinted polymerrdquo Journalof Environmental Chemical Engineering vol 3 no 2 pp 1267ndash1276 2015
[26] N T Tavengwa E Cukrowska and L Chimuka ldquoSynthesis ofbulk ion-imprinted polymers (IIPs) embedded with oleic acidcoated Fe
3O4for selective extraction of hexavalent uraniumrdquo
Water SA vol 40 no 4 pp 623ndash630 2014[27] M Solgy M Taghizadeh and D Ghoddocynejad ldquoAdsorption
of uranium(VI) from sulphate solutions using Amberlite IRA-402 resin equilibrium kinetics and thermodynamics studyrdquoAnnals of Nuclear Energy vol 75 pp 132ndash138 2015
[28] J Li X Yang C Bai et al ldquoA novel benzimidazole-functionalized 2-D COF material synthesis and application as
a selective solid-phase extractant for separation of uraniumrdquoJournal of Colloid and Interface Science vol 437 pp 211ndash2182015
[29] N T Tavengwa E Cukrowska and L Chimuka ldquoSelectiveadsorption of uranium (VI) on NaHCO
3leached composite
120574-methacryloxypropyltrimethoxysilane coated magnetic ion-imprinted polymers prepared by precipitation polymerizationrdquoSouth African Journal of Chemistry vol 68 pp 61ndash68 2015
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Journal of Engineering 5
0
60
120
180
0 30 60 90Time (min)
qt
(mg
g)
R-1R-2
Figure 3 Effect of time on adsorption process
four five or six amine active sites of R-1 and R-2 resins[10] The molar ratios of sorbed U(VI) ions and resins activesites are 1 4 1 5 and 1 6 The experimental maximumsorption capacities of 92mgg (039mmolg) and 158mgg(066mmolg) for R-1 and R-2 are closer to the theoreticalsorption value corresponding to the molar ratio of 1 6 (092and 14mmolg for R-1 and R-2) The observed differencesbetween the experimental and expected sorption capacitiesvalues may be attributed to the nonaccessibility of all activesites for coordination with U(VI)This behavior confirms theeffect of textural properties on the nature of binding as wellas the sorption capacity
32 Effect of Contact Time and Adsorption Kinetics Sorptionof U(VI) on both R-1 and R-2 resins was investigated as afunction of contact time and the data obtained are shownin Figure 3 Uranium sorption increased as the contact timeincreased and reached its maximum sorption capacities at45 and 30min on R-1 and R-2 respectively To verify theorder of the adsorption process pseudo-first-order kineticsand pseudo-second-order kineticsmodels [10 12] were testedaccording to the following equations
Pseudo first order log (119902119890minus 119902119905) = log (119902
1st) minus1198961
2303119905
Pseudo second order 119905119902119905
=1
119896211990222nd+1
119902119890
119905
(1)
where 119902119890is the maximum experimental sorption capacity
(mg gminus1) 119902119905is the experimental sorption capacity at time (119905)
(mg gminus1) 1199021st is the calculated sorption capacity according
to pseudo-first-order model (mg gminus1) 1198961is the rate constant
of pseudo-first-order (minminus1) 1199022nd is the calculated sorption
capacity according to pseudo-second-order model (mg gminus1)and 119896
2is the rate constant of pseudo-second-order (minminus1)
Values of 1198961and 119902
1st were calculated from the slope andintercept values of plotting log(119902
119890minus 119902119905) versus (119905) as shown in
Figure 4 The plot of 119905119902119905versus (119905) (Figure 5) gives a straight
line with slope and intercept equal to 1119902119890and 1119896
2119902119890
2
05
1
15
2
0 10 20 30 40Time (min)
R-1R-2
log(qeminusqt)
Figure 4 The pseudo-first-order kinetics model
0
02
04
06
0 20 40 60Time (min)
tqt
R-1R-2
Figure 5 The pseudo-second-order kinetics model
respectivelyThe calculated values of 1198961 1199021st 1198962 and 1199022nd were
reported in Table 2The obtained data (119902 and 1198772) proved that the adsorption
rate is likely to be controlled by pseudo-second-order kineticmodel rather than the pseudo-first-order kinetic modelThe rate of adsorption is less controlled by intraparticlediffusion due to the bulky size of U(VI) ions that implies thatadsorption of U(VI) is dependent on concentration of boththe metal ions and active sites concentrations
33 Effect of Adsorption Temperature The temperature effecton U(VI) adsorption was tested as function of 4 temperaturedegrees (298 303 313 and 323) (Figure 6) An increase intemperature resulting in an increase in the amount of U(VI)adsorbed per unit mass of all resins might be attributed tothe change in surface properties of the sorbent and solubilityof the solute species with endothermic nature of the sorptionprocess
34 Adsorption Isotherms A relation between the amount ofadsorbate adsorbed on a given surface at constant temper-ature and the equilibrium concentration of the substrate in
6 Journal of Engineering
Table 2 Kinetic data for adsorption of U(VI) on R-1 and R-2 resins
Resin Experimental Pseudo-first-order kinetics Pseudo-second-order kinetics119902119890(mgg) 119902
1st (mgg) 1198961(minminus1) 119877
21199022nd (mgg) 119896
2(minminus1) 119877
2
R-1 92 5117 006 0942 100 0003 0997R-2 158 7413 007 0935 200 0002 0993
0
40
80
120
0 30 60 90
R-1
0
60
120
180
0 15 30 45
R-2
Ce (mgL)
qe
(mg
g)
Ce (mgL)
qe
(mg
g)298K303K
313K323K
298K303K
313K323K
Figure 6 Effect of adsorption temperature on adsorption process
0
03
06
09
0 20 40 60
R-1
0
005
01
015
0 10 20 30
R-2
Ce (mgL) Ce (mgL)
Ceq
e(g
L)
Ceq
e(g
L)
298K303K
313K323K
298K303K
313K323K
Figure 7 Langmuir adsorption isotherm
contact with the adsorbent is known as adsorption isothermAdsorption isotherms depend on certain parameters whosevalues express the surface properties and the affinity of thesorbent We can compute experimental results from equilib-rium experiences by several adsorption isotherm models
(1) Langmuir Model The most widely used isotherm equa-tion for modeling equilibrium data is the Langmuir modelLangmuir derived a relation between adsorbed material andits equilibrium concentration [10 13 14] The linear form ofLangmuir equation is given by
119862119890
119902119890
=119862119890
119902max+
1
119870119871119876max
(2)
where 119862119890is the equilibrium concentration of ions in solution
(mg Lminus1) 119902119890is the amount adsorbed at 119862
119890(mg gminus1) 119876max
is the maximum adsorption capacity (mg gminus1) and 119870119871is
the binding constant which is related to the energy ofadsorption (Lmgminus1) Plotting 119862
119890119902119890against 119862
119890(Figure 7)
gives a straight line with slope and intercept equal to 1119876maxand 1119870
119871119876max respectively The values of 119870
119871and 119876max at
different temperatures are reported in Table 3 The values of119870119871and119876max increase as the temperature increases Increasing
of119870119871value with increasing of temperature implies the strong
binding between U(VI) ions and the active sites at elevatedtemperatures
The thermodynamic parameters such as enthalpy change(Δ119867∘) and entropy change (Δ119878∘) corresponding to U(IV)sorption on the studied resins were calculated using VanrsquotHoff equation [10]
ln119870119871=Δ119878∘
119877minusΔ119867∘
119877119879 (3)
where 119877 is the universal gas constant (8314 Jmolminus1sdotKminus1)and 119879 is the absolute temperature (Kelvin) Plotting ln 119870
119871
against 1119879 (Figure 8) gives a straight line with interceptand slope equal to Δ119878∘119877 and minusΔ119867∘119877 respectively Thevalues of Δ119878∘ and Δ119867∘ were calculated and reported in
Journal of Engineering 7
Table 3 Isotherms parameters for the sorption of U(VI) ions
Resin Experimental 119902119890(mgg) Langmuir parameters Freundlich parameters
119870119871(Lmol) 119876Max (mgg) 119877
2119899 119870
119891(mgg) 119877
2
R-1 92 0026 100 0981 1247 3083 09907R-2 158 0133 16667 0977 1887 26485 08233
Resin Temkin parameters D-R parameters119861 (Jmol) 119860
119879(Lg) 119877
2119902119904(mgg) 119870ad (mol2kJ2) 119864 (kJmol2) 119877
2
R-1 5414 0080 0871 9454 9 times 10minus5 7454 085R-2 5127 0681 0934 1697 5 times 10minus5 100 0923
Table 4 Thermodynamic parameters for adsorption of U(VI) by R-1 and R-2 at different temperatures
Resin Temp (Kelvin) Thermodynamic parametersΔ119867∘ (kJmol) Δ119878
∘ (KJmolsdotK) 119879Δ119878∘ (kJmol) Δ119866
∘ (kJmol)
R-1
298
27328 016445
4901 minus2168303 4983 minus225313 5147 minus2414323 5312 minus2579
R-2
298
26064 01741
5188 minus2582303 5275 minus2669313 5449 minus2843323 5623 minus3017
Table 4 The positive Δ119867∘ value indicates that the adsorptionprocess is endothermic The positive value of Δ119878∘ maybe explained by the increased degree of randomness atthe resinsolution interface during the progress of sorptionprocess This phenomenon could be ascribed to liberation offree water molecules as a result of the substitution reactionbetween chelating amine active sites and hydrated U(VI)ion The Gibbs free energy of adsorption reaction (Δ119866∘) wascalculated using the following relation [10]
Δ119866∘= Δ119867
∘minus 119879Δ119878
∘ (4)
The values of Δ119866∘ values (Table 4) confirm the spon-taneous nature and feasibility of the sorption process andthe favorable U(VI) sorption takes place with increasing oftemperature
The suitability of the resins towards metal ions is throughthe values of separation factor constant (119877
119871) where 119877
119871gt 1
(unsuitable) 119877119871= 1 (linear) 0 lt 119877
119871lt 1 (suitable) 119877
119871= 0
(irreversible) [10] The value of 119877119871could be calculated from
(4)
119877119871=
1
1 + 119870119871119862119900
(5)
where 119862119900is the initial concentration of U(VI) ions (mM)
The values of 119877119871for sorption of U(VI) on R-1 and R-2
resins at different temperature were calculated and foundto lie between 0041 and 0281 indicating their suitability asadsorbents for U(VI)
(2) Freundlich Model The Freundlich isotherm model [1516] is an empirical relationship that describes the sorptionof solutes on a solid surface assuming that different sites
8
9
10
11
12
00031 00033 00035
1T (Kminus1)
ln K
L
R-1R-2
Figure 8 Vanrsquot Hoff plots for the adsorption process
with several sorption energies are involved (the surface ofadsorbent is heterogeneous)This isothermmodel is given by(3)
log 119902119890= log119870
119865+log119862119890
119899 (6)
where 119902119890(mg gminus1) and 119862
119890(mg Lminus1) are the equilibrium
concentrations of U(VI) in the solid and liquid phaserespectively 119870
119865(mg gminus1) and n are characteristic constants
related to the relative sorption capacity of the sorbent and theintensity of sorption respectively The higher the 1119899 valueis the more favorable the adsorption is generally 119899 lt 1 1119899and log119870
119865are the slope and intercept respectively given by
8 Journal of Engineering
0
05
1
15
2
25
0 05 1 15 2
log q
e
log Ce
R-1R-2
Figure 9 Freundlich adsorption isotherms
plotting log 119902119890against log119862
119890 The Freundlich plot (Figure 9)
gave a slope less than unity indicating the nonlinear sorptionbehavior with U(VI) in the concentration range studiedThe observed values of 119870
119865of R-1 and R-2 were found
to be 305 and 2649 (mg gminus1) The values of equilibriumsorption capacity and correlation coefficients of Langmuirequation (119876max) are more consistent with the experimentaldata than Freundlich isothermmodelTherefore the sorptionreaction is more favorable by Langmuir model confirmingthe monolayer coverage of uranium onto the amine resins
(3) Temkinrsquos Model The derivation of the Temkin isothermassumes that the fall in the heat of sorption is linear ratherthan logarithmic as implied in the Freundlich equation [1516] The linear form of Temkin isotherm is given by thefollowing equation
119902119890=119877119879
119887ln119860119879+119877119879
119887ln119862119890
119861 =119877119879
119887
119902119890= 119861 ln119860
119879+ 119861 ln119862
119890
(7)
where 119860119879is Temkin isotherm equilibrium binding constant
(Lg) 119887 is Temkin isotherm constant 119877 is universal gasconstant (8314 JmolK) 119879 is temperature at 298K and 119861is constant related to heat of sorption (Jmol) where 119902
119890
(mg gminus1) and 119862119890(mg Lminus1) are the equilibrium concentrations
of U(VI) in the solid and liquid phase respectively Plotting119902119890versus ln119862
119890(Figure 10) should give a straight line if the
adsorption energy decreases linearly with increasing surfacecoverage According to the given relation of 119902
119890versus ln119862
119890
the estimated 119861 values of R-1 and R-2 were 5127ndash5414 Jmolthat indicate the favorability of the chemical adsorptionprocess
341 Dubinin-Radushkevich Isotherm Model The Dubinin-Radushkevich (D-R) isotherm model is more general thanthe Langmuir isotherm as its deviation is not based on ideal
0
60
120
180
0 1 2 3 4 5
qe
ln Ce
R-1R-2
Figure 10 Temkin adsorption isotherms
assumptions such as equipotential of sorption sites absenceof steric hindrances between sorbed and incoming particlesand surface homogeneity onmicroscopic levelThis isothermmodel is a temperature-dependentmodel used to estimate thecharacteristic porosity in addition to the apparent energy ofadsorption as well as expressing the adsorption mechanism[15 17] The model is represented by the following equations
119902119890= (119902119904) exp(minus119870ad (119877119879 ln [1 +
1
119862119890
])
2
)
120576 = 119877119879 ln [1 + 1
119862119890
]
119902119890= (119902119904) exp (minus119870ad120576
2)
(8)
where 119902119890is the amount of adsorbate in the adsorbent at
equilibrium (mgg) 119902119904is the theoretical isotherm saturation
capacity (mgg)119870ad is the D-R isotherm constant (mol2kJ2)related to free energy of sorption 120576 is the D-R isothermconstant 119877 represents the gas constant (8314 Jmol K) 119879 isabsolute temperature (K) and 119862
119890is adsorbate equilibrium
concentration (mgL) The linearity of D-R isotherm modelis represented by the following equation
ln 119902119890= ln 119902
119904minus 119870ad120576
2 (9)
A plot of ln 119902119890versus 1205762 yielded straight lines indicating a
good fit of the isotherm to the experimental data (Figure 11)and the values of 119902
119904and119870ad for D-R isothermwere calculated
(Table 3) 119902119904and 1198772 values were observed that this isotherm
also gave very good description of the sorption process Thehigh values of 119902
119904show high sorption capacity The approach
was usually applied to distinguish the physical and chemicaladsorption of metal ions with its mean free energy permolecule of adsorbate The apparent energy (119864 = KJmol2) ofadsorption can be computed calculated using the followingrelation
119864 = [1
radic2119870ad] (10)
Journal of Engineering 9
3
4
5
6
0 20000 40000 60000
R-1R-2
ln q e
1205762
Figure 11 Dubinin-Radushkevich isotherm model
0
25
50
75
100
0
50
100
150
200
250
0 05 1 15
Adso
rptio
n ca
paci
ty (m
gg)
Solidliquid (mgmL)
Adso
rptio
n effi
cien
cy (
)
R-1 (mgg)R-2 (mgg)R-1 ()R-2 ()
Figure 12 The effect of the solidliquid ratio on the adsorptionefficiency
The values of the apparent energy of adsorption alsodepict chemisorption process
35 SolidLiquid Ratio The effect of the solidliquid ratio onthe adsorption efficiency of the studied resins was achievedusing variable amounts of R-1 and R-2 resins (0025 to 0125 g)in 100mL of the adsorption medium and the results wereshowed in Figure 12 The adsorption efficiency of the resinsincreased with increasing their dose while the adsorptioncapacities decreased This result is reasonable if we considerthat as the higher resin dose in the solution as the higheravailability of active sites for metal ion adsorption
36 Resin Regeneration For desorption studies 05 g of theuranium loaded dry resin with uranium was gently washedwith distilled water to remove any unabsorbed metal ionsand then shaken with 100mL of 01M HNO
3for 30min
and finally the uranium concentration was determined in thefiltrate All the experiments were performed in duplicate withexperimental error plusmn05ndash2 After the uranium elution theresins were regenerated by washing with 1M NaOH solutionfollowed by washing with distilled water hence the resinbecame regenerated and ready for the next use Regenerationefficiency was found to be about 90ndash96 for two resins over3 cycles
It is worth mentioning that using of the eluted resinswithout alkalinewashing failed to adsorbmore uranium ionswhich can be ascribed to the protonation of the amino activegroups that prevent the U(VI) ions adsorption Accordinglytreatment with the alkaline solution converted these proto-nated groups into free ones which have the affinity towardsthe U(VI) ions
37 Application of the Studied Resins for Granite SamplesThree granite rock samples were collected from Gabal Gattarpluton located inNorth EasternDesert of EgyptThe sampleswere crushed and ground to minus200 mesh size and analyzed byconventional wet chemical techniques for their major oxidecompositions as well as by XRF for some trace elements Thechemical analysis of the studied granitic samples is given inTable 5 The granitic samples contain high concentration ofFe2O3(t) Rb Y Nb U and Th and low concentration of Sr
and Ba compared with similar Egyptian granitesFor thework purpose the uranium content in the granitic
samples was selectively leached using nitric acid solution(2M) for 6 hours at 60∘C The reacted slurry was filteredand washed with hot water The obtained filtrate was treatedwith R-1 and R-2 for the uranium separation The uptakeresults of U(VI) ions (Table 6) showed that both the resinsdisplayed higher removal efficiency towards U(VI) relative toother metal ions present in sample solution
4 Conclusion
Magnetic glycidyl methacrylate resin particles with nano-magnetite core and glycidyl methacrylateNN1015840-methylene-bis-acrylamide resin shell were prepared and modified withDA and TA The studied resins showed high adsorptioncapacities towards uranium ions reached 92 and 158mggfor R-1 and R-2 respectively The results revealed that thepseudo-second-order sorption is the predominant mech-anism The amount of U(VI) adsorbed per unit mass ofall resins increased as temperature increased showing theendothermic nature of the sorption process The experimen-tal results from equilibrium experiences were computed byseveral adsorption isotherm models Langmuir FreundlichTemkin and Dubinin-Radushkevich isotherm model Theresults showed that the sorption reaction is more favorableby Langmuir model confirming the monolayer coverage ofuraniumonto the amine resins and indicate the favorability ofthe chemical adsorption processThe positive heat of adsorp-tion indicates that the adsorption process is endothermicThe
10 Journal of Engineering
Table 5 Chemical analysis of granitic samples
Sample Majorconstituent Trace
constituentConcentration
ppm
1
SiO2
735 U 4000AL2O3
128 Th 300Fe2O3
25 Rare earth 270CaO 13 Rb 225Na2O 26 Zr 197
MgO 05 Y 126K2O 24
2
SiO2
735 U 3200AL2O3
138 Th 190Fe2O3
36 Rare earth 270CaO 14 Rb mdashNa2O 06 Zr 400
MgO 05 Y 197K2O 24
3
SiO2
725 U 2700AL2O3
128 Th 260Fe2O3
25 Rare earth 250CaO 13 Rb 437Na2O 39 Zr 284
MgO 05 Y 135K2O 34
Table 6 Results of treatment of the granite samples with the studiedresins
Resin Metal ion Removal efficiency ()Sample 1 Sample 2 Sample 3
R-1U(VI) 93 93 928Fe(III) 26 25 26RE2O3
15 15 15
R-2U(VI) 995 992 99Fe(III) 31 31 31RE2O3
55 80 85
positive value of Δ119878∘ points to increasing of the randomnessdegree at the resinsolution interface during the progress ofsorption process The negative values of Δ119866∘ values confirmthe spontaneous nature of the sorption process
Finally it can be concluded that
(1) the prepared magnetite-cored resins have advantagetoward the filtration process where the magnetiteparticles impart the magnetic properties to the beadsthat allow rapid and easy separation of beads by theapplication of an external magnetic field avoidingsome technical problems arising due to using thetraditional filter papers
(2) the magnetite core allows more spreading of theactive group on the surface of resin particles thatenhance the adsorption efficiency comparing to othernonmagnetite core resins [10]
(3) the prepared resins are recommended as effectiveadsorbate materials regarding separation of uraniumions from their bearing solutions particularly in thepresence of other competitive metal ions
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] O Philippova A Barabanova V Molchanov and A KhokhlovldquoMagnetic polymer beads recent trends and developments insynthetic design and applicationsrdquo European Polymer Journalvol 47 no 4 pp 542ndash559 2011
[2] Q Yuan and R A Williams ldquoLarge scale manufacture ofmagnetic polymer particles using membranes and microfluidicdevicesrdquo China Particuology vol 5 no 1-2 pp 26ndash42 2007
[3] C-Y Chen C-L Chiang and P-C Huang ldquoAdsorptions ofheavy metal ions by a magnetic chelating resin containinghydroxy and iminodiacetate groupsrdquo Separation and Purifica-tion Technology vol 50 no 1 pp 15ndash21 2006
[4] D Horak B Rittich and A Spanova ldquoCarboxyl-functionalizedmagnetic microparticle carrier for isolation and identificationof DNA in dairy productsrdquo Journal of Magnetism and MagneticMaterials vol 311 no 1 pp 249ndash254 2007
[5] AAAtia AMDonia andA E Shahin ldquoStudies on the uptakebehavior of a magnetic Co
3O4-containing resin for Ni(II)
Cu(II) andHg(II) from their aqueous solutionsrdquo Separation andPurification Technology vol 46 no 3 pp 208ndash213 2005
[6] A M Donia A A Atia H A El-Boraey and D H MabroukldquoAdsorption of Ag(I) on glycidyl methacrylateNN1015840-methylenebis-acrylamide chelating resins with embedded iron oxiderdquoSeparation and Purification Technology vol 48 no 3 pp 281ndash287 2006
[7] A M Donia A A Atia H A El-Boraey and D H MabroukldquoUptake studies of copper(II) on glycidyl methacrylate chelat-ing resin containing Fe
2O3particlesrdquo Separation and Purifica-
tion Technology vol 49 no 1 pp 64ndash70 2006[8] A M Donia A A Atia and K Z Elwakeel ldquoSelective sepa-
ration of mercury(II) using magnetic chitosan resin modifiedwith Schiff rsquos base derived from thiourea and glutaraldehyderdquoJournal of Hazardous Materials vol 151 no 2-3 pp 372ndash3792008
[9] K Z Elwakeel and A A Atia ldquoUptake of U(VI) from aqueousmedia by magnetic Schiff rsquos base chitosan compositerdquo Journal ofCleaner Production vol 70 pp 292ndash302 2014
[10] A M Donia A A Atia E M M Moussa A M El-Sherifand M O Abd El-Magied ldquoRemoval of uranium(VI) fromaqueous solutions using glycidyl methacrylate chelating resinsrdquoHydrometallurgy vol 95 no 3-4 pp 183ndash189 2009
[11] Z Marczenko Separation and Spectrophotometric Determina-tion of Elements Ellis Harwood Chichester UK 1986
[12] S A Sadeek M A El-Sayed M M Amine and M O Abd El-Magied ldquoA chelating resin containing trihydroxybenzoic acidas the functional group synthesis and adsorption behavior forTh(IV) and U(VI) ionsrdquo Journal of Radioanalytical and NuclearChemistry vol 299 no 3 pp 1299ndash1306 2014
[13] W Dong and S C Brooks ldquoDetermination of the formationconstants of ternary complexes of uranyl and carbonate with
Journal of Engineering 11
alkaline earth metals (Mg2+ Ca2+ Sr2+ and Ba2+) using anionexchangemethodrdquoEnvironmental ScienceampTechnology vol 40no 15 pp 4689ndash4695 2006
[14] C Xiong X Liu and C Yao ldquoEffect of pH on sorptionfor RE(III) and sorption behaviors of Sm(III) by D152 resinrdquoJournal of Rare Earths vol 26 no 6 pp 851ndash856 2008
[15] A O Dada A P Olalekan A M Olatunya and O DadaldquoLangmuir Freundlich Temkin and Dubinin-Radushkevichisotherms studies of equilibrium sorption of Zn2+ unto phos-phoric acid modified rice huskrdquo Journal of Applied Chemistryvol 3 no 1 pp 38ndash45 2012
[16] V P Mpofu J Addai-Mensah and J Ralston ldquoTemperatureinfluence of nonionic polyethylene oxide and anionic polyacry-lamide on flocculation and dewatering behavior of kaolinitedispersionsrdquo Journal of Colloid and Interface Science vol 271no 1 pp 145ndash156 2004
[17] A U Itodo andHU Itodo ldquoSorption energies estimation usingDubinin-Radushkevich andTemkin adsorption isothermsrdquo LifeScience Journal vol 7 no 4 pp 31ndash39 2010
[18] K Dev R Pathak and G N Rao ldquoSorption behaviour oflanthanum(III) neodymium(III) terbium(III) thorium(IV)and uranium(VI) on Amberlite XAD-4 resin functionalizedwith bicine ligandsrdquo Talanta vol 48 no 3 pp 579ndash584 1999
[19] V K Jain A Handa S S Sait P Shrivastav and Y K AgrawalldquoPre-concentration separation and trace determination of lan-thanum(III) cerium(III) thorium(IV) and uranium(VI) onpolymer supported o-vanillinsemicarbazonerdquo Analytica Chim-ica Acta vol 429 no 2 pp 237ndash246 2001
[20] M Nogami I M Ismail M Yamaguchi and K SuzukildquoSynthesis characterization and some adsorption properties ofTMMA chelating resinrdquo Journal of Solid State Chemistry vol171 no 1-2 pp 353ndash357 2003
[21] P Metilda K Sanghamitra J M Gladis G R K Naiduand T Prasada Rao ldquoAmberlite XAD-4 functionalized withsuccinic acid for the solid phase extractive preconcentrationand separation of uranium(VI)rdquo Talanta vol 65 no 1 pp 192ndash200 2005
[22] DH Phillips B GuD BWatson andC S Parmele ldquoUraniumremoval from contaminated groundwater by synthetic resinsrdquoWater Research vol 42 no 1-2 pp 260ndash268 2008
[23] Y Jung S Kim S-J Park and J M Kim ldquoApplication ofpolymer-modified nanoporous silica to adsorbents of uranylionsrdquo Colloids and Surfaces A vol 313-314 pp 162ndash166 2008
[24] G Tian J Geng Y Jin et al ldquoSorption of uranium(VI) usingoxime-grafted ordered mesoporous carbon CMK-5rdquo Journal ofHazardous Materials vol 190 no 1ndash3 pp 442ndash450 2011
[25] T S Anirudhan J Nima and P L Divya ldquoAdsorption and sep-aration behavior of uranium(VI) by 4-vinylpyridine-grafted-vinyltriethoxysilane-cellulose ion imprinted polymerrdquo Journalof Environmental Chemical Engineering vol 3 no 2 pp 1267ndash1276 2015
[26] N T Tavengwa E Cukrowska and L Chimuka ldquoSynthesis ofbulk ion-imprinted polymers (IIPs) embedded with oleic acidcoated Fe
3O4for selective extraction of hexavalent uraniumrdquo
Water SA vol 40 no 4 pp 623ndash630 2014[27] M Solgy M Taghizadeh and D Ghoddocynejad ldquoAdsorption
of uranium(VI) from sulphate solutions using Amberlite IRA-402 resin equilibrium kinetics and thermodynamics studyrdquoAnnals of Nuclear Energy vol 75 pp 132ndash138 2015
[28] J Li X Yang C Bai et al ldquoA novel benzimidazole-functionalized 2-D COF material synthesis and application as
a selective solid-phase extractant for separation of uraniumrdquoJournal of Colloid and Interface Science vol 437 pp 211ndash2182015
[29] N T Tavengwa E Cukrowska and L Chimuka ldquoSelectiveadsorption of uranium (VI) on NaHCO
3leached composite
120574-methacryloxypropyltrimethoxysilane coated magnetic ion-imprinted polymers prepared by precipitation polymerizationrdquoSouth African Journal of Chemistry vol 68 pp 61ndash68 2015
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
6 Journal of Engineering
Table 2 Kinetic data for adsorption of U(VI) on R-1 and R-2 resins
Resin Experimental Pseudo-first-order kinetics Pseudo-second-order kinetics119902119890(mgg) 119902
1st (mgg) 1198961(minminus1) 119877
21199022nd (mgg) 119896
2(minminus1) 119877
2
R-1 92 5117 006 0942 100 0003 0997R-2 158 7413 007 0935 200 0002 0993
0
40
80
120
0 30 60 90
R-1
0
60
120
180
0 15 30 45
R-2
Ce (mgL)
qe
(mg
g)
Ce (mgL)
qe
(mg
g)298K303K
313K323K
298K303K
313K323K
Figure 6 Effect of adsorption temperature on adsorption process
0
03
06
09
0 20 40 60
R-1
0
005
01
015
0 10 20 30
R-2
Ce (mgL) Ce (mgL)
Ceq
e(g
L)
Ceq
e(g
L)
298K303K
313K323K
298K303K
313K323K
Figure 7 Langmuir adsorption isotherm
contact with the adsorbent is known as adsorption isothermAdsorption isotherms depend on certain parameters whosevalues express the surface properties and the affinity of thesorbent We can compute experimental results from equilib-rium experiences by several adsorption isotherm models
(1) Langmuir Model The most widely used isotherm equa-tion for modeling equilibrium data is the Langmuir modelLangmuir derived a relation between adsorbed material andits equilibrium concentration [10 13 14] The linear form ofLangmuir equation is given by
119862119890
119902119890
=119862119890
119902max+
1
119870119871119876max
(2)
where 119862119890is the equilibrium concentration of ions in solution
(mg Lminus1) 119902119890is the amount adsorbed at 119862
119890(mg gminus1) 119876max
is the maximum adsorption capacity (mg gminus1) and 119870119871is
the binding constant which is related to the energy ofadsorption (Lmgminus1) Plotting 119862
119890119902119890against 119862
119890(Figure 7)
gives a straight line with slope and intercept equal to 1119876maxand 1119870
119871119876max respectively The values of 119870
119871and 119876max at
different temperatures are reported in Table 3 The values of119870119871and119876max increase as the temperature increases Increasing
of119870119871value with increasing of temperature implies the strong
binding between U(VI) ions and the active sites at elevatedtemperatures
The thermodynamic parameters such as enthalpy change(Δ119867∘) and entropy change (Δ119878∘) corresponding to U(IV)sorption on the studied resins were calculated using VanrsquotHoff equation [10]
ln119870119871=Δ119878∘
119877minusΔ119867∘
119877119879 (3)
where 119877 is the universal gas constant (8314 Jmolminus1sdotKminus1)and 119879 is the absolute temperature (Kelvin) Plotting ln 119870
119871
against 1119879 (Figure 8) gives a straight line with interceptand slope equal to Δ119878∘119877 and minusΔ119867∘119877 respectively Thevalues of Δ119878∘ and Δ119867∘ were calculated and reported in
Journal of Engineering 7
Table 3 Isotherms parameters for the sorption of U(VI) ions
Resin Experimental 119902119890(mgg) Langmuir parameters Freundlich parameters
119870119871(Lmol) 119876Max (mgg) 119877
2119899 119870
119891(mgg) 119877
2
R-1 92 0026 100 0981 1247 3083 09907R-2 158 0133 16667 0977 1887 26485 08233
Resin Temkin parameters D-R parameters119861 (Jmol) 119860
119879(Lg) 119877
2119902119904(mgg) 119870ad (mol2kJ2) 119864 (kJmol2) 119877
2
R-1 5414 0080 0871 9454 9 times 10minus5 7454 085R-2 5127 0681 0934 1697 5 times 10minus5 100 0923
Table 4 Thermodynamic parameters for adsorption of U(VI) by R-1 and R-2 at different temperatures
Resin Temp (Kelvin) Thermodynamic parametersΔ119867∘ (kJmol) Δ119878
∘ (KJmolsdotK) 119879Δ119878∘ (kJmol) Δ119866
∘ (kJmol)
R-1
298
27328 016445
4901 minus2168303 4983 minus225313 5147 minus2414323 5312 minus2579
R-2
298
26064 01741
5188 minus2582303 5275 minus2669313 5449 minus2843323 5623 minus3017
Table 4 The positive Δ119867∘ value indicates that the adsorptionprocess is endothermic The positive value of Δ119878∘ maybe explained by the increased degree of randomness atthe resinsolution interface during the progress of sorptionprocess This phenomenon could be ascribed to liberation offree water molecules as a result of the substitution reactionbetween chelating amine active sites and hydrated U(VI)ion The Gibbs free energy of adsorption reaction (Δ119866∘) wascalculated using the following relation [10]
Δ119866∘= Δ119867
∘minus 119879Δ119878
∘ (4)
The values of Δ119866∘ values (Table 4) confirm the spon-taneous nature and feasibility of the sorption process andthe favorable U(VI) sorption takes place with increasing oftemperature
The suitability of the resins towards metal ions is throughthe values of separation factor constant (119877
119871) where 119877
119871gt 1
(unsuitable) 119877119871= 1 (linear) 0 lt 119877
119871lt 1 (suitable) 119877
119871= 0
(irreversible) [10] The value of 119877119871could be calculated from
(4)
119877119871=
1
1 + 119870119871119862119900
(5)
where 119862119900is the initial concentration of U(VI) ions (mM)
The values of 119877119871for sorption of U(VI) on R-1 and R-2
resins at different temperature were calculated and foundto lie between 0041 and 0281 indicating their suitability asadsorbents for U(VI)
(2) Freundlich Model The Freundlich isotherm model [1516] is an empirical relationship that describes the sorptionof solutes on a solid surface assuming that different sites
8
9
10
11
12
00031 00033 00035
1T (Kminus1)
ln K
L
R-1R-2
Figure 8 Vanrsquot Hoff plots for the adsorption process
with several sorption energies are involved (the surface ofadsorbent is heterogeneous)This isothermmodel is given by(3)
log 119902119890= log119870
119865+log119862119890
119899 (6)
where 119902119890(mg gminus1) and 119862
119890(mg Lminus1) are the equilibrium
concentrations of U(VI) in the solid and liquid phaserespectively 119870
119865(mg gminus1) and n are characteristic constants
related to the relative sorption capacity of the sorbent and theintensity of sorption respectively The higher the 1119899 valueis the more favorable the adsorption is generally 119899 lt 1 1119899and log119870
119865are the slope and intercept respectively given by
8 Journal of Engineering
0
05
1
15
2
25
0 05 1 15 2
log q
e
log Ce
R-1R-2
Figure 9 Freundlich adsorption isotherms
plotting log 119902119890against log119862
119890 The Freundlich plot (Figure 9)
gave a slope less than unity indicating the nonlinear sorptionbehavior with U(VI) in the concentration range studiedThe observed values of 119870
119865of R-1 and R-2 were found
to be 305 and 2649 (mg gminus1) The values of equilibriumsorption capacity and correlation coefficients of Langmuirequation (119876max) are more consistent with the experimentaldata than Freundlich isothermmodelTherefore the sorptionreaction is more favorable by Langmuir model confirmingthe monolayer coverage of uranium onto the amine resins
(3) Temkinrsquos Model The derivation of the Temkin isothermassumes that the fall in the heat of sorption is linear ratherthan logarithmic as implied in the Freundlich equation [1516] The linear form of Temkin isotherm is given by thefollowing equation
119902119890=119877119879
119887ln119860119879+119877119879
119887ln119862119890
119861 =119877119879
119887
119902119890= 119861 ln119860
119879+ 119861 ln119862
119890
(7)
where 119860119879is Temkin isotherm equilibrium binding constant
(Lg) 119887 is Temkin isotherm constant 119877 is universal gasconstant (8314 JmolK) 119879 is temperature at 298K and 119861is constant related to heat of sorption (Jmol) where 119902
119890
(mg gminus1) and 119862119890(mg Lminus1) are the equilibrium concentrations
of U(VI) in the solid and liquid phase respectively Plotting119902119890versus ln119862
119890(Figure 10) should give a straight line if the
adsorption energy decreases linearly with increasing surfacecoverage According to the given relation of 119902
119890versus ln119862
119890
the estimated 119861 values of R-1 and R-2 were 5127ndash5414 Jmolthat indicate the favorability of the chemical adsorptionprocess
341 Dubinin-Radushkevich Isotherm Model The Dubinin-Radushkevich (D-R) isotherm model is more general thanthe Langmuir isotherm as its deviation is not based on ideal
0
60
120
180
0 1 2 3 4 5
qe
ln Ce
R-1R-2
Figure 10 Temkin adsorption isotherms
assumptions such as equipotential of sorption sites absenceof steric hindrances between sorbed and incoming particlesand surface homogeneity onmicroscopic levelThis isothermmodel is a temperature-dependentmodel used to estimate thecharacteristic porosity in addition to the apparent energy ofadsorption as well as expressing the adsorption mechanism[15 17] The model is represented by the following equations
119902119890= (119902119904) exp(minus119870ad (119877119879 ln [1 +
1
119862119890
])
2
)
120576 = 119877119879 ln [1 + 1
119862119890
]
119902119890= (119902119904) exp (minus119870ad120576
2)
(8)
where 119902119890is the amount of adsorbate in the adsorbent at
equilibrium (mgg) 119902119904is the theoretical isotherm saturation
capacity (mgg)119870ad is the D-R isotherm constant (mol2kJ2)related to free energy of sorption 120576 is the D-R isothermconstant 119877 represents the gas constant (8314 Jmol K) 119879 isabsolute temperature (K) and 119862
119890is adsorbate equilibrium
concentration (mgL) The linearity of D-R isotherm modelis represented by the following equation
ln 119902119890= ln 119902
119904minus 119870ad120576
2 (9)
A plot of ln 119902119890versus 1205762 yielded straight lines indicating a
good fit of the isotherm to the experimental data (Figure 11)and the values of 119902
119904and119870ad for D-R isothermwere calculated
(Table 3) 119902119904and 1198772 values were observed that this isotherm
also gave very good description of the sorption process Thehigh values of 119902
119904show high sorption capacity The approach
was usually applied to distinguish the physical and chemicaladsorption of metal ions with its mean free energy permolecule of adsorbate The apparent energy (119864 = KJmol2) ofadsorption can be computed calculated using the followingrelation
119864 = [1
radic2119870ad] (10)
Journal of Engineering 9
3
4
5
6
0 20000 40000 60000
R-1R-2
ln q e
1205762
Figure 11 Dubinin-Radushkevich isotherm model
0
25
50
75
100
0
50
100
150
200
250
0 05 1 15
Adso
rptio
n ca
paci
ty (m
gg)
Solidliquid (mgmL)
Adso
rptio
n effi
cien
cy (
)
R-1 (mgg)R-2 (mgg)R-1 ()R-2 ()
Figure 12 The effect of the solidliquid ratio on the adsorptionefficiency
The values of the apparent energy of adsorption alsodepict chemisorption process
35 SolidLiquid Ratio The effect of the solidliquid ratio onthe adsorption efficiency of the studied resins was achievedusing variable amounts of R-1 and R-2 resins (0025 to 0125 g)in 100mL of the adsorption medium and the results wereshowed in Figure 12 The adsorption efficiency of the resinsincreased with increasing their dose while the adsorptioncapacities decreased This result is reasonable if we considerthat as the higher resin dose in the solution as the higheravailability of active sites for metal ion adsorption
36 Resin Regeneration For desorption studies 05 g of theuranium loaded dry resin with uranium was gently washedwith distilled water to remove any unabsorbed metal ionsand then shaken with 100mL of 01M HNO
3for 30min
and finally the uranium concentration was determined in thefiltrate All the experiments were performed in duplicate withexperimental error plusmn05ndash2 After the uranium elution theresins were regenerated by washing with 1M NaOH solutionfollowed by washing with distilled water hence the resinbecame regenerated and ready for the next use Regenerationefficiency was found to be about 90ndash96 for two resins over3 cycles
It is worth mentioning that using of the eluted resinswithout alkalinewashing failed to adsorbmore uranium ionswhich can be ascribed to the protonation of the amino activegroups that prevent the U(VI) ions adsorption Accordinglytreatment with the alkaline solution converted these proto-nated groups into free ones which have the affinity towardsthe U(VI) ions
37 Application of the Studied Resins for Granite SamplesThree granite rock samples were collected from Gabal Gattarpluton located inNorth EasternDesert of EgyptThe sampleswere crushed and ground to minus200 mesh size and analyzed byconventional wet chemical techniques for their major oxidecompositions as well as by XRF for some trace elements Thechemical analysis of the studied granitic samples is given inTable 5 The granitic samples contain high concentration ofFe2O3(t) Rb Y Nb U and Th and low concentration of Sr
and Ba compared with similar Egyptian granitesFor thework purpose the uranium content in the granitic
samples was selectively leached using nitric acid solution(2M) for 6 hours at 60∘C The reacted slurry was filteredand washed with hot water The obtained filtrate was treatedwith R-1 and R-2 for the uranium separation The uptakeresults of U(VI) ions (Table 6) showed that both the resinsdisplayed higher removal efficiency towards U(VI) relative toother metal ions present in sample solution
4 Conclusion
Magnetic glycidyl methacrylate resin particles with nano-magnetite core and glycidyl methacrylateNN1015840-methylene-bis-acrylamide resin shell were prepared and modified withDA and TA The studied resins showed high adsorptioncapacities towards uranium ions reached 92 and 158mggfor R-1 and R-2 respectively The results revealed that thepseudo-second-order sorption is the predominant mech-anism The amount of U(VI) adsorbed per unit mass ofall resins increased as temperature increased showing theendothermic nature of the sorption process The experimen-tal results from equilibrium experiences were computed byseveral adsorption isotherm models Langmuir FreundlichTemkin and Dubinin-Radushkevich isotherm model Theresults showed that the sorption reaction is more favorableby Langmuir model confirming the monolayer coverage ofuraniumonto the amine resins and indicate the favorability ofthe chemical adsorption processThe positive heat of adsorp-tion indicates that the adsorption process is endothermicThe
10 Journal of Engineering
Table 5 Chemical analysis of granitic samples
Sample Majorconstituent Trace
constituentConcentration
ppm
1
SiO2
735 U 4000AL2O3
128 Th 300Fe2O3
25 Rare earth 270CaO 13 Rb 225Na2O 26 Zr 197
MgO 05 Y 126K2O 24
2
SiO2
735 U 3200AL2O3
138 Th 190Fe2O3
36 Rare earth 270CaO 14 Rb mdashNa2O 06 Zr 400
MgO 05 Y 197K2O 24
3
SiO2
725 U 2700AL2O3
128 Th 260Fe2O3
25 Rare earth 250CaO 13 Rb 437Na2O 39 Zr 284
MgO 05 Y 135K2O 34
Table 6 Results of treatment of the granite samples with the studiedresins
Resin Metal ion Removal efficiency ()Sample 1 Sample 2 Sample 3
R-1U(VI) 93 93 928Fe(III) 26 25 26RE2O3
15 15 15
R-2U(VI) 995 992 99Fe(III) 31 31 31RE2O3
55 80 85
positive value of Δ119878∘ points to increasing of the randomnessdegree at the resinsolution interface during the progress ofsorption process The negative values of Δ119866∘ values confirmthe spontaneous nature of the sorption process
Finally it can be concluded that
(1) the prepared magnetite-cored resins have advantagetoward the filtration process where the magnetiteparticles impart the magnetic properties to the beadsthat allow rapid and easy separation of beads by theapplication of an external magnetic field avoidingsome technical problems arising due to using thetraditional filter papers
(2) the magnetite core allows more spreading of theactive group on the surface of resin particles thatenhance the adsorption efficiency comparing to othernonmagnetite core resins [10]
(3) the prepared resins are recommended as effectiveadsorbate materials regarding separation of uraniumions from their bearing solutions particularly in thepresence of other competitive metal ions
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] O Philippova A Barabanova V Molchanov and A KhokhlovldquoMagnetic polymer beads recent trends and developments insynthetic design and applicationsrdquo European Polymer Journalvol 47 no 4 pp 542ndash559 2011
[2] Q Yuan and R A Williams ldquoLarge scale manufacture ofmagnetic polymer particles using membranes and microfluidicdevicesrdquo China Particuology vol 5 no 1-2 pp 26ndash42 2007
[3] C-Y Chen C-L Chiang and P-C Huang ldquoAdsorptions ofheavy metal ions by a magnetic chelating resin containinghydroxy and iminodiacetate groupsrdquo Separation and Purifica-tion Technology vol 50 no 1 pp 15ndash21 2006
[4] D Horak B Rittich and A Spanova ldquoCarboxyl-functionalizedmagnetic microparticle carrier for isolation and identificationof DNA in dairy productsrdquo Journal of Magnetism and MagneticMaterials vol 311 no 1 pp 249ndash254 2007
[5] AAAtia AMDonia andA E Shahin ldquoStudies on the uptakebehavior of a magnetic Co
3O4-containing resin for Ni(II)
Cu(II) andHg(II) from their aqueous solutionsrdquo Separation andPurification Technology vol 46 no 3 pp 208ndash213 2005
[6] A M Donia A A Atia H A El-Boraey and D H MabroukldquoAdsorption of Ag(I) on glycidyl methacrylateNN1015840-methylenebis-acrylamide chelating resins with embedded iron oxiderdquoSeparation and Purification Technology vol 48 no 3 pp 281ndash287 2006
[7] A M Donia A A Atia H A El-Boraey and D H MabroukldquoUptake studies of copper(II) on glycidyl methacrylate chelat-ing resin containing Fe
2O3particlesrdquo Separation and Purifica-
tion Technology vol 49 no 1 pp 64ndash70 2006[8] A M Donia A A Atia and K Z Elwakeel ldquoSelective sepa-
ration of mercury(II) using magnetic chitosan resin modifiedwith Schiff rsquos base derived from thiourea and glutaraldehyderdquoJournal of Hazardous Materials vol 151 no 2-3 pp 372ndash3792008
[9] K Z Elwakeel and A A Atia ldquoUptake of U(VI) from aqueousmedia by magnetic Schiff rsquos base chitosan compositerdquo Journal ofCleaner Production vol 70 pp 292ndash302 2014
[10] A M Donia A A Atia E M M Moussa A M El-Sherifand M O Abd El-Magied ldquoRemoval of uranium(VI) fromaqueous solutions using glycidyl methacrylate chelating resinsrdquoHydrometallurgy vol 95 no 3-4 pp 183ndash189 2009
[11] Z Marczenko Separation and Spectrophotometric Determina-tion of Elements Ellis Harwood Chichester UK 1986
[12] S A Sadeek M A El-Sayed M M Amine and M O Abd El-Magied ldquoA chelating resin containing trihydroxybenzoic acidas the functional group synthesis and adsorption behavior forTh(IV) and U(VI) ionsrdquo Journal of Radioanalytical and NuclearChemistry vol 299 no 3 pp 1299ndash1306 2014
[13] W Dong and S C Brooks ldquoDetermination of the formationconstants of ternary complexes of uranyl and carbonate with
Journal of Engineering 11
alkaline earth metals (Mg2+ Ca2+ Sr2+ and Ba2+) using anionexchangemethodrdquoEnvironmental ScienceampTechnology vol 40no 15 pp 4689ndash4695 2006
[14] C Xiong X Liu and C Yao ldquoEffect of pH on sorptionfor RE(III) and sorption behaviors of Sm(III) by D152 resinrdquoJournal of Rare Earths vol 26 no 6 pp 851ndash856 2008
[15] A O Dada A P Olalekan A M Olatunya and O DadaldquoLangmuir Freundlich Temkin and Dubinin-Radushkevichisotherms studies of equilibrium sorption of Zn2+ unto phos-phoric acid modified rice huskrdquo Journal of Applied Chemistryvol 3 no 1 pp 38ndash45 2012
[16] V P Mpofu J Addai-Mensah and J Ralston ldquoTemperatureinfluence of nonionic polyethylene oxide and anionic polyacry-lamide on flocculation and dewatering behavior of kaolinitedispersionsrdquo Journal of Colloid and Interface Science vol 271no 1 pp 145ndash156 2004
[17] A U Itodo andHU Itodo ldquoSorption energies estimation usingDubinin-Radushkevich andTemkin adsorption isothermsrdquo LifeScience Journal vol 7 no 4 pp 31ndash39 2010
[18] K Dev R Pathak and G N Rao ldquoSorption behaviour oflanthanum(III) neodymium(III) terbium(III) thorium(IV)and uranium(VI) on Amberlite XAD-4 resin functionalizedwith bicine ligandsrdquo Talanta vol 48 no 3 pp 579ndash584 1999
[19] V K Jain A Handa S S Sait P Shrivastav and Y K AgrawalldquoPre-concentration separation and trace determination of lan-thanum(III) cerium(III) thorium(IV) and uranium(VI) onpolymer supported o-vanillinsemicarbazonerdquo Analytica Chim-ica Acta vol 429 no 2 pp 237ndash246 2001
[20] M Nogami I M Ismail M Yamaguchi and K SuzukildquoSynthesis characterization and some adsorption properties ofTMMA chelating resinrdquo Journal of Solid State Chemistry vol171 no 1-2 pp 353ndash357 2003
[21] P Metilda K Sanghamitra J M Gladis G R K Naiduand T Prasada Rao ldquoAmberlite XAD-4 functionalized withsuccinic acid for the solid phase extractive preconcentrationand separation of uranium(VI)rdquo Talanta vol 65 no 1 pp 192ndash200 2005
[22] DH Phillips B GuD BWatson andC S Parmele ldquoUraniumremoval from contaminated groundwater by synthetic resinsrdquoWater Research vol 42 no 1-2 pp 260ndash268 2008
[23] Y Jung S Kim S-J Park and J M Kim ldquoApplication ofpolymer-modified nanoporous silica to adsorbents of uranylionsrdquo Colloids and Surfaces A vol 313-314 pp 162ndash166 2008
[24] G Tian J Geng Y Jin et al ldquoSorption of uranium(VI) usingoxime-grafted ordered mesoporous carbon CMK-5rdquo Journal ofHazardous Materials vol 190 no 1ndash3 pp 442ndash450 2011
[25] T S Anirudhan J Nima and P L Divya ldquoAdsorption and sep-aration behavior of uranium(VI) by 4-vinylpyridine-grafted-vinyltriethoxysilane-cellulose ion imprinted polymerrdquo Journalof Environmental Chemical Engineering vol 3 no 2 pp 1267ndash1276 2015
[26] N T Tavengwa E Cukrowska and L Chimuka ldquoSynthesis ofbulk ion-imprinted polymers (IIPs) embedded with oleic acidcoated Fe
3O4for selective extraction of hexavalent uraniumrdquo
Water SA vol 40 no 4 pp 623ndash630 2014[27] M Solgy M Taghizadeh and D Ghoddocynejad ldquoAdsorption
of uranium(VI) from sulphate solutions using Amberlite IRA-402 resin equilibrium kinetics and thermodynamics studyrdquoAnnals of Nuclear Energy vol 75 pp 132ndash138 2015
[28] J Li X Yang C Bai et al ldquoA novel benzimidazole-functionalized 2-D COF material synthesis and application as
a selective solid-phase extractant for separation of uraniumrdquoJournal of Colloid and Interface Science vol 437 pp 211ndash2182015
[29] N T Tavengwa E Cukrowska and L Chimuka ldquoSelectiveadsorption of uranium (VI) on NaHCO
3leached composite
120574-methacryloxypropyltrimethoxysilane coated magnetic ion-imprinted polymers prepared by precipitation polymerizationrdquoSouth African Journal of Chemistry vol 68 pp 61ndash68 2015
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
Journal of Engineering 7
Table 3 Isotherms parameters for the sorption of U(VI) ions
Resin Experimental 119902119890(mgg) Langmuir parameters Freundlich parameters
119870119871(Lmol) 119876Max (mgg) 119877
2119899 119870
119891(mgg) 119877
2
R-1 92 0026 100 0981 1247 3083 09907R-2 158 0133 16667 0977 1887 26485 08233
Resin Temkin parameters D-R parameters119861 (Jmol) 119860
119879(Lg) 119877
2119902119904(mgg) 119870ad (mol2kJ2) 119864 (kJmol2) 119877
2
R-1 5414 0080 0871 9454 9 times 10minus5 7454 085R-2 5127 0681 0934 1697 5 times 10minus5 100 0923
Table 4 Thermodynamic parameters for adsorption of U(VI) by R-1 and R-2 at different temperatures
Resin Temp (Kelvin) Thermodynamic parametersΔ119867∘ (kJmol) Δ119878
∘ (KJmolsdotK) 119879Δ119878∘ (kJmol) Δ119866
∘ (kJmol)
R-1
298
27328 016445
4901 minus2168303 4983 minus225313 5147 minus2414323 5312 minus2579
R-2
298
26064 01741
5188 minus2582303 5275 minus2669313 5449 minus2843323 5623 minus3017
Table 4 The positive Δ119867∘ value indicates that the adsorptionprocess is endothermic The positive value of Δ119878∘ maybe explained by the increased degree of randomness atthe resinsolution interface during the progress of sorptionprocess This phenomenon could be ascribed to liberation offree water molecules as a result of the substitution reactionbetween chelating amine active sites and hydrated U(VI)ion The Gibbs free energy of adsorption reaction (Δ119866∘) wascalculated using the following relation [10]
Δ119866∘= Δ119867
∘minus 119879Δ119878
∘ (4)
The values of Δ119866∘ values (Table 4) confirm the spon-taneous nature and feasibility of the sorption process andthe favorable U(VI) sorption takes place with increasing oftemperature
The suitability of the resins towards metal ions is throughthe values of separation factor constant (119877
119871) where 119877
119871gt 1
(unsuitable) 119877119871= 1 (linear) 0 lt 119877
119871lt 1 (suitable) 119877
119871= 0
(irreversible) [10] The value of 119877119871could be calculated from
(4)
119877119871=
1
1 + 119870119871119862119900
(5)
where 119862119900is the initial concentration of U(VI) ions (mM)
The values of 119877119871for sorption of U(VI) on R-1 and R-2
resins at different temperature were calculated and foundto lie between 0041 and 0281 indicating their suitability asadsorbents for U(VI)
(2) Freundlich Model The Freundlich isotherm model [1516] is an empirical relationship that describes the sorptionof solutes on a solid surface assuming that different sites
8
9
10
11
12
00031 00033 00035
1T (Kminus1)
ln K
L
R-1R-2
Figure 8 Vanrsquot Hoff plots for the adsorption process
with several sorption energies are involved (the surface ofadsorbent is heterogeneous)This isothermmodel is given by(3)
log 119902119890= log119870
119865+log119862119890
119899 (6)
where 119902119890(mg gminus1) and 119862
119890(mg Lminus1) are the equilibrium
concentrations of U(VI) in the solid and liquid phaserespectively 119870
119865(mg gminus1) and n are characteristic constants
related to the relative sorption capacity of the sorbent and theintensity of sorption respectively The higher the 1119899 valueis the more favorable the adsorption is generally 119899 lt 1 1119899and log119870
119865are the slope and intercept respectively given by
8 Journal of Engineering
0
05
1
15
2
25
0 05 1 15 2
log q
e
log Ce
R-1R-2
Figure 9 Freundlich adsorption isotherms
plotting log 119902119890against log119862
119890 The Freundlich plot (Figure 9)
gave a slope less than unity indicating the nonlinear sorptionbehavior with U(VI) in the concentration range studiedThe observed values of 119870
119865of R-1 and R-2 were found
to be 305 and 2649 (mg gminus1) The values of equilibriumsorption capacity and correlation coefficients of Langmuirequation (119876max) are more consistent with the experimentaldata than Freundlich isothermmodelTherefore the sorptionreaction is more favorable by Langmuir model confirmingthe monolayer coverage of uranium onto the amine resins
(3) Temkinrsquos Model The derivation of the Temkin isothermassumes that the fall in the heat of sorption is linear ratherthan logarithmic as implied in the Freundlich equation [1516] The linear form of Temkin isotherm is given by thefollowing equation
119902119890=119877119879
119887ln119860119879+119877119879
119887ln119862119890
119861 =119877119879
119887
119902119890= 119861 ln119860
119879+ 119861 ln119862
119890
(7)
where 119860119879is Temkin isotherm equilibrium binding constant
(Lg) 119887 is Temkin isotherm constant 119877 is universal gasconstant (8314 JmolK) 119879 is temperature at 298K and 119861is constant related to heat of sorption (Jmol) where 119902
119890
(mg gminus1) and 119862119890(mg Lminus1) are the equilibrium concentrations
of U(VI) in the solid and liquid phase respectively Plotting119902119890versus ln119862
119890(Figure 10) should give a straight line if the
adsorption energy decreases linearly with increasing surfacecoverage According to the given relation of 119902
119890versus ln119862
119890
the estimated 119861 values of R-1 and R-2 were 5127ndash5414 Jmolthat indicate the favorability of the chemical adsorptionprocess
341 Dubinin-Radushkevich Isotherm Model The Dubinin-Radushkevich (D-R) isotherm model is more general thanthe Langmuir isotherm as its deviation is not based on ideal
0
60
120
180
0 1 2 3 4 5
qe
ln Ce
R-1R-2
Figure 10 Temkin adsorption isotherms
assumptions such as equipotential of sorption sites absenceof steric hindrances between sorbed and incoming particlesand surface homogeneity onmicroscopic levelThis isothermmodel is a temperature-dependentmodel used to estimate thecharacteristic porosity in addition to the apparent energy ofadsorption as well as expressing the adsorption mechanism[15 17] The model is represented by the following equations
119902119890= (119902119904) exp(minus119870ad (119877119879 ln [1 +
1
119862119890
])
2
)
120576 = 119877119879 ln [1 + 1
119862119890
]
119902119890= (119902119904) exp (minus119870ad120576
2)
(8)
where 119902119890is the amount of adsorbate in the adsorbent at
equilibrium (mgg) 119902119904is the theoretical isotherm saturation
capacity (mgg)119870ad is the D-R isotherm constant (mol2kJ2)related to free energy of sorption 120576 is the D-R isothermconstant 119877 represents the gas constant (8314 Jmol K) 119879 isabsolute temperature (K) and 119862
119890is adsorbate equilibrium
concentration (mgL) The linearity of D-R isotherm modelis represented by the following equation
ln 119902119890= ln 119902
119904minus 119870ad120576
2 (9)
A plot of ln 119902119890versus 1205762 yielded straight lines indicating a
good fit of the isotherm to the experimental data (Figure 11)and the values of 119902
119904and119870ad for D-R isothermwere calculated
(Table 3) 119902119904and 1198772 values were observed that this isotherm
also gave very good description of the sorption process Thehigh values of 119902
119904show high sorption capacity The approach
was usually applied to distinguish the physical and chemicaladsorption of metal ions with its mean free energy permolecule of adsorbate The apparent energy (119864 = KJmol2) ofadsorption can be computed calculated using the followingrelation
119864 = [1
radic2119870ad] (10)
Journal of Engineering 9
3
4
5
6
0 20000 40000 60000
R-1R-2
ln q e
1205762
Figure 11 Dubinin-Radushkevich isotherm model
0
25
50
75
100
0
50
100
150
200
250
0 05 1 15
Adso
rptio
n ca
paci
ty (m
gg)
Solidliquid (mgmL)
Adso
rptio
n effi
cien
cy (
)
R-1 (mgg)R-2 (mgg)R-1 ()R-2 ()
Figure 12 The effect of the solidliquid ratio on the adsorptionefficiency
The values of the apparent energy of adsorption alsodepict chemisorption process
35 SolidLiquid Ratio The effect of the solidliquid ratio onthe adsorption efficiency of the studied resins was achievedusing variable amounts of R-1 and R-2 resins (0025 to 0125 g)in 100mL of the adsorption medium and the results wereshowed in Figure 12 The adsorption efficiency of the resinsincreased with increasing their dose while the adsorptioncapacities decreased This result is reasonable if we considerthat as the higher resin dose in the solution as the higheravailability of active sites for metal ion adsorption
36 Resin Regeneration For desorption studies 05 g of theuranium loaded dry resin with uranium was gently washedwith distilled water to remove any unabsorbed metal ionsand then shaken with 100mL of 01M HNO
3for 30min
and finally the uranium concentration was determined in thefiltrate All the experiments were performed in duplicate withexperimental error plusmn05ndash2 After the uranium elution theresins were regenerated by washing with 1M NaOH solutionfollowed by washing with distilled water hence the resinbecame regenerated and ready for the next use Regenerationefficiency was found to be about 90ndash96 for two resins over3 cycles
It is worth mentioning that using of the eluted resinswithout alkalinewashing failed to adsorbmore uranium ionswhich can be ascribed to the protonation of the amino activegroups that prevent the U(VI) ions adsorption Accordinglytreatment with the alkaline solution converted these proto-nated groups into free ones which have the affinity towardsthe U(VI) ions
37 Application of the Studied Resins for Granite SamplesThree granite rock samples were collected from Gabal Gattarpluton located inNorth EasternDesert of EgyptThe sampleswere crushed and ground to minus200 mesh size and analyzed byconventional wet chemical techniques for their major oxidecompositions as well as by XRF for some trace elements Thechemical analysis of the studied granitic samples is given inTable 5 The granitic samples contain high concentration ofFe2O3(t) Rb Y Nb U and Th and low concentration of Sr
and Ba compared with similar Egyptian granitesFor thework purpose the uranium content in the granitic
samples was selectively leached using nitric acid solution(2M) for 6 hours at 60∘C The reacted slurry was filteredand washed with hot water The obtained filtrate was treatedwith R-1 and R-2 for the uranium separation The uptakeresults of U(VI) ions (Table 6) showed that both the resinsdisplayed higher removal efficiency towards U(VI) relative toother metal ions present in sample solution
4 Conclusion
Magnetic glycidyl methacrylate resin particles with nano-magnetite core and glycidyl methacrylateNN1015840-methylene-bis-acrylamide resin shell were prepared and modified withDA and TA The studied resins showed high adsorptioncapacities towards uranium ions reached 92 and 158mggfor R-1 and R-2 respectively The results revealed that thepseudo-second-order sorption is the predominant mech-anism The amount of U(VI) adsorbed per unit mass ofall resins increased as temperature increased showing theendothermic nature of the sorption process The experimen-tal results from equilibrium experiences were computed byseveral adsorption isotherm models Langmuir FreundlichTemkin and Dubinin-Radushkevich isotherm model Theresults showed that the sorption reaction is more favorableby Langmuir model confirming the monolayer coverage ofuraniumonto the amine resins and indicate the favorability ofthe chemical adsorption processThe positive heat of adsorp-tion indicates that the adsorption process is endothermicThe
10 Journal of Engineering
Table 5 Chemical analysis of granitic samples
Sample Majorconstituent Trace
constituentConcentration
ppm
1
SiO2
735 U 4000AL2O3
128 Th 300Fe2O3
25 Rare earth 270CaO 13 Rb 225Na2O 26 Zr 197
MgO 05 Y 126K2O 24
2
SiO2
735 U 3200AL2O3
138 Th 190Fe2O3
36 Rare earth 270CaO 14 Rb mdashNa2O 06 Zr 400
MgO 05 Y 197K2O 24
3
SiO2
725 U 2700AL2O3
128 Th 260Fe2O3
25 Rare earth 250CaO 13 Rb 437Na2O 39 Zr 284
MgO 05 Y 135K2O 34
Table 6 Results of treatment of the granite samples with the studiedresins
Resin Metal ion Removal efficiency ()Sample 1 Sample 2 Sample 3
R-1U(VI) 93 93 928Fe(III) 26 25 26RE2O3
15 15 15
R-2U(VI) 995 992 99Fe(III) 31 31 31RE2O3
55 80 85
positive value of Δ119878∘ points to increasing of the randomnessdegree at the resinsolution interface during the progress ofsorption process The negative values of Δ119866∘ values confirmthe spontaneous nature of the sorption process
Finally it can be concluded that
(1) the prepared magnetite-cored resins have advantagetoward the filtration process where the magnetiteparticles impart the magnetic properties to the beadsthat allow rapid and easy separation of beads by theapplication of an external magnetic field avoidingsome technical problems arising due to using thetraditional filter papers
(2) the magnetite core allows more spreading of theactive group on the surface of resin particles thatenhance the adsorption efficiency comparing to othernonmagnetite core resins [10]
(3) the prepared resins are recommended as effectiveadsorbate materials regarding separation of uraniumions from their bearing solutions particularly in thepresence of other competitive metal ions
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] O Philippova A Barabanova V Molchanov and A KhokhlovldquoMagnetic polymer beads recent trends and developments insynthetic design and applicationsrdquo European Polymer Journalvol 47 no 4 pp 542ndash559 2011
[2] Q Yuan and R A Williams ldquoLarge scale manufacture ofmagnetic polymer particles using membranes and microfluidicdevicesrdquo China Particuology vol 5 no 1-2 pp 26ndash42 2007
[3] C-Y Chen C-L Chiang and P-C Huang ldquoAdsorptions ofheavy metal ions by a magnetic chelating resin containinghydroxy and iminodiacetate groupsrdquo Separation and Purifica-tion Technology vol 50 no 1 pp 15ndash21 2006
[4] D Horak B Rittich and A Spanova ldquoCarboxyl-functionalizedmagnetic microparticle carrier for isolation and identificationof DNA in dairy productsrdquo Journal of Magnetism and MagneticMaterials vol 311 no 1 pp 249ndash254 2007
[5] AAAtia AMDonia andA E Shahin ldquoStudies on the uptakebehavior of a magnetic Co
3O4-containing resin for Ni(II)
Cu(II) andHg(II) from their aqueous solutionsrdquo Separation andPurification Technology vol 46 no 3 pp 208ndash213 2005
[6] A M Donia A A Atia H A El-Boraey and D H MabroukldquoAdsorption of Ag(I) on glycidyl methacrylateNN1015840-methylenebis-acrylamide chelating resins with embedded iron oxiderdquoSeparation and Purification Technology vol 48 no 3 pp 281ndash287 2006
[7] A M Donia A A Atia H A El-Boraey and D H MabroukldquoUptake studies of copper(II) on glycidyl methacrylate chelat-ing resin containing Fe
2O3particlesrdquo Separation and Purifica-
tion Technology vol 49 no 1 pp 64ndash70 2006[8] A M Donia A A Atia and K Z Elwakeel ldquoSelective sepa-
ration of mercury(II) using magnetic chitosan resin modifiedwith Schiff rsquos base derived from thiourea and glutaraldehyderdquoJournal of Hazardous Materials vol 151 no 2-3 pp 372ndash3792008
[9] K Z Elwakeel and A A Atia ldquoUptake of U(VI) from aqueousmedia by magnetic Schiff rsquos base chitosan compositerdquo Journal ofCleaner Production vol 70 pp 292ndash302 2014
[10] A M Donia A A Atia E M M Moussa A M El-Sherifand M O Abd El-Magied ldquoRemoval of uranium(VI) fromaqueous solutions using glycidyl methacrylate chelating resinsrdquoHydrometallurgy vol 95 no 3-4 pp 183ndash189 2009
[11] Z Marczenko Separation and Spectrophotometric Determina-tion of Elements Ellis Harwood Chichester UK 1986
[12] S A Sadeek M A El-Sayed M M Amine and M O Abd El-Magied ldquoA chelating resin containing trihydroxybenzoic acidas the functional group synthesis and adsorption behavior forTh(IV) and U(VI) ionsrdquo Journal of Radioanalytical and NuclearChemistry vol 299 no 3 pp 1299ndash1306 2014
[13] W Dong and S C Brooks ldquoDetermination of the formationconstants of ternary complexes of uranyl and carbonate with
Journal of Engineering 11
alkaline earth metals (Mg2+ Ca2+ Sr2+ and Ba2+) using anionexchangemethodrdquoEnvironmental ScienceampTechnology vol 40no 15 pp 4689ndash4695 2006
[14] C Xiong X Liu and C Yao ldquoEffect of pH on sorptionfor RE(III) and sorption behaviors of Sm(III) by D152 resinrdquoJournal of Rare Earths vol 26 no 6 pp 851ndash856 2008
[15] A O Dada A P Olalekan A M Olatunya and O DadaldquoLangmuir Freundlich Temkin and Dubinin-Radushkevichisotherms studies of equilibrium sorption of Zn2+ unto phos-phoric acid modified rice huskrdquo Journal of Applied Chemistryvol 3 no 1 pp 38ndash45 2012
[16] V P Mpofu J Addai-Mensah and J Ralston ldquoTemperatureinfluence of nonionic polyethylene oxide and anionic polyacry-lamide on flocculation and dewatering behavior of kaolinitedispersionsrdquo Journal of Colloid and Interface Science vol 271no 1 pp 145ndash156 2004
[17] A U Itodo andHU Itodo ldquoSorption energies estimation usingDubinin-Radushkevich andTemkin adsorption isothermsrdquo LifeScience Journal vol 7 no 4 pp 31ndash39 2010
[18] K Dev R Pathak and G N Rao ldquoSorption behaviour oflanthanum(III) neodymium(III) terbium(III) thorium(IV)and uranium(VI) on Amberlite XAD-4 resin functionalizedwith bicine ligandsrdquo Talanta vol 48 no 3 pp 579ndash584 1999
[19] V K Jain A Handa S S Sait P Shrivastav and Y K AgrawalldquoPre-concentration separation and trace determination of lan-thanum(III) cerium(III) thorium(IV) and uranium(VI) onpolymer supported o-vanillinsemicarbazonerdquo Analytica Chim-ica Acta vol 429 no 2 pp 237ndash246 2001
[20] M Nogami I M Ismail M Yamaguchi and K SuzukildquoSynthesis characterization and some adsorption properties ofTMMA chelating resinrdquo Journal of Solid State Chemistry vol171 no 1-2 pp 353ndash357 2003
[21] P Metilda K Sanghamitra J M Gladis G R K Naiduand T Prasada Rao ldquoAmberlite XAD-4 functionalized withsuccinic acid for the solid phase extractive preconcentrationand separation of uranium(VI)rdquo Talanta vol 65 no 1 pp 192ndash200 2005
[22] DH Phillips B GuD BWatson andC S Parmele ldquoUraniumremoval from contaminated groundwater by synthetic resinsrdquoWater Research vol 42 no 1-2 pp 260ndash268 2008
[23] Y Jung S Kim S-J Park and J M Kim ldquoApplication ofpolymer-modified nanoporous silica to adsorbents of uranylionsrdquo Colloids and Surfaces A vol 313-314 pp 162ndash166 2008
[24] G Tian J Geng Y Jin et al ldquoSorption of uranium(VI) usingoxime-grafted ordered mesoporous carbon CMK-5rdquo Journal ofHazardous Materials vol 190 no 1ndash3 pp 442ndash450 2011
[25] T S Anirudhan J Nima and P L Divya ldquoAdsorption and sep-aration behavior of uranium(VI) by 4-vinylpyridine-grafted-vinyltriethoxysilane-cellulose ion imprinted polymerrdquo Journalof Environmental Chemical Engineering vol 3 no 2 pp 1267ndash1276 2015
[26] N T Tavengwa E Cukrowska and L Chimuka ldquoSynthesis ofbulk ion-imprinted polymers (IIPs) embedded with oleic acidcoated Fe
3O4for selective extraction of hexavalent uraniumrdquo
Water SA vol 40 no 4 pp 623ndash630 2014[27] M Solgy M Taghizadeh and D Ghoddocynejad ldquoAdsorption
of uranium(VI) from sulphate solutions using Amberlite IRA-402 resin equilibrium kinetics and thermodynamics studyrdquoAnnals of Nuclear Energy vol 75 pp 132ndash138 2015
[28] J Li X Yang C Bai et al ldquoA novel benzimidazole-functionalized 2-D COF material synthesis and application as
a selective solid-phase extractant for separation of uraniumrdquoJournal of Colloid and Interface Science vol 437 pp 211ndash2182015
[29] N T Tavengwa E Cukrowska and L Chimuka ldquoSelectiveadsorption of uranium (VI) on NaHCO
3leached composite
120574-methacryloxypropyltrimethoxysilane coated magnetic ion-imprinted polymers prepared by precipitation polymerizationrdquoSouth African Journal of Chemistry vol 68 pp 61ndash68 2015
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Navigation and Observation
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DistributedSensor Networks
International Journal of
8 Journal of Engineering
0
05
1
15
2
25
0 05 1 15 2
log q
e
log Ce
R-1R-2
Figure 9 Freundlich adsorption isotherms
plotting log 119902119890against log119862
119890 The Freundlich plot (Figure 9)
gave a slope less than unity indicating the nonlinear sorptionbehavior with U(VI) in the concentration range studiedThe observed values of 119870
119865of R-1 and R-2 were found
to be 305 and 2649 (mg gminus1) The values of equilibriumsorption capacity and correlation coefficients of Langmuirequation (119876max) are more consistent with the experimentaldata than Freundlich isothermmodelTherefore the sorptionreaction is more favorable by Langmuir model confirmingthe monolayer coverage of uranium onto the amine resins
(3) Temkinrsquos Model The derivation of the Temkin isothermassumes that the fall in the heat of sorption is linear ratherthan logarithmic as implied in the Freundlich equation [1516] The linear form of Temkin isotherm is given by thefollowing equation
119902119890=119877119879
119887ln119860119879+119877119879
119887ln119862119890
119861 =119877119879
119887
119902119890= 119861 ln119860
119879+ 119861 ln119862
119890
(7)
where 119860119879is Temkin isotherm equilibrium binding constant
(Lg) 119887 is Temkin isotherm constant 119877 is universal gasconstant (8314 JmolK) 119879 is temperature at 298K and 119861is constant related to heat of sorption (Jmol) where 119902
119890
(mg gminus1) and 119862119890(mg Lminus1) are the equilibrium concentrations
of U(VI) in the solid and liquid phase respectively Plotting119902119890versus ln119862
119890(Figure 10) should give a straight line if the
adsorption energy decreases linearly with increasing surfacecoverage According to the given relation of 119902
119890versus ln119862
119890
the estimated 119861 values of R-1 and R-2 were 5127ndash5414 Jmolthat indicate the favorability of the chemical adsorptionprocess
341 Dubinin-Radushkevich Isotherm Model The Dubinin-Radushkevich (D-R) isotherm model is more general thanthe Langmuir isotherm as its deviation is not based on ideal
0
60
120
180
0 1 2 3 4 5
qe
ln Ce
R-1R-2
Figure 10 Temkin adsorption isotherms
assumptions such as equipotential of sorption sites absenceof steric hindrances between sorbed and incoming particlesand surface homogeneity onmicroscopic levelThis isothermmodel is a temperature-dependentmodel used to estimate thecharacteristic porosity in addition to the apparent energy ofadsorption as well as expressing the adsorption mechanism[15 17] The model is represented by the following equations
119902119890= (119902119904) exp(minus119870ad (119877119879 ln [1 +
1
119862119890
])
2
)
120576 = 119877119879 ln [1 + 1
119862119890
]
119902119890= (119902119904) exp (minus119870ad120576
2)
(8)
where 119902119890is the amount of adsorbate in the adsorbent at
equilibrium (mgg) 119902119904is the theoretical isotherm saturation
capacity (mgg)119870ad is the D-R isotherm constant (mol2kJ2)related to free energy of sorption 120576 is the D-R isothermconstant 119877 represents the gas constant (8314 Jmol K) 119879 isabsolute temperature (K) and 119862
119890is adsorbate equilibrium
concentration (mgL) The linearity of D-R isotherm modelis represented by the following equation
ln 119902119890= ln 119902
119904minus 119870ad120576
2 (9)
A plot of ln 119902119890versus 1205762 yielded straight lines indicating a
good fit of the isotherm to the experimental data (Figure 11)and the values of 119902
119904and119870ad for D-R isothermwere calculated
(Table 3) 119902119904and 1198772 values were observed that this isotherm
also gave very good description of the sorption process Thehigh values of 119902
119904show high sorption capacity The approach
was usually applied to distinguish the physical and chemicaladsorption of metal ions with its mean free energy permolecule of adsorbate The apparent energy (119864 = KJmol2) ofadsorption can be computed calculated using the followingrelation
119864 = [1
radic2119870ad] (10)
Journal of Engineering 9
3
4
5
6
0 20000 40000 60000
R-1R-2
ln q e
1205762
Figure 11 Dubinin-Radushkevich isotherm model
0
25
50
75
100
0
50
100
150
200
250
0 05 1 15
Adso
rptio
n ca
paci
ty (m
gg)
Solidliquid (mgmL)
Adso
rptio
n effi
cien
cy (
)
R-1 (mgg)R-2 (mgg)R-1 ()R-2 ()
Figure 12 The effect of the solidliquid ratio on the adsorptionefficiency
The values of the apparent energy of adsorption alsodepict chemisorption process
35 SolidLiquid Ratio The effect of the solidliquid ratio onthe adsorption efficiency of the studied resins was achievedusing variable amounts of R-1 and R-2 resins (0025 to 0125 g)in 100mL of the adsorption medium and the results wereshowed in Figure 12 The adsorption efficiency of the resinsincreased with increasing their dose while the adsorptioncapacities decreased This result is reasonable if we considerthat as the higher resin dose in the solution as the higheravailability of active sites for metal ion adsorption
36 Resin Regeneration For desorption studies 05 g of theuranium loaded dry resin with uranium was gently washedwith distilled water to remove any unabsorbed metal ionsand then shaken with 100mL of 01M HNO
3for 30min
and finally the uranium concentration was determined in thefiltrate All the experiments were performed in duplicate withexperimental error plusmn05ndash2 After the uranium elution theresins were regenerated by washing with 1M NaOH solutionfollowed by washing with distilled water hence the resinbecame regenerated and ready for the next use Regenerationefficiency was found to be about 90ndash96 for two resins over3 cycles
It is worth mentioning that using of the eluted resinswithout alkalinewashing failed to adsorbmore uranium ionswhich can be ascribed to the protonation of the amino activegroups that prevent the U(VI) ions adsorption Accordinglytreatment with the alkaline solution converted these proto-nated groups into free ones which have the affinity towardsthe U(VI) ions
37 Application of the Studied Resins for Granite SamplesThree granite rock samples were collected from Gabal Gattarpluton located inNorth EasternDesert of EgyptThe sampleswere crushed and ground to minus200 mesh size and analyzed byconventional wet chemical techniques for their major oxidecompositions as well as by XRF for some trace elements Thechemical analysis of the studied granitic samples is given inTable 5 The granitic samples contain high concentration ofFe2O3(t) Rb Y Nb U and Th and low concentration of Sr
and Ba compared with similar Egyptian granitesFor thework purpose the uranium content in the granitic
samples was selectively leached using nitric acid solution(2M) for 6 hours at 60∘C The reacted slurry was filteredand washed with hot water The obtained filtrate was treatedwith R-1 and R-2 for the uranium separation The uptakeresults of U(VI) ions (Table 6) showed that both the resinsdisplayed higher removal efficiency towards U(VI) relative toother metal ions present in sample solution
4 Conclusion
Magnetic glycidyl methacrylate resin particles with nano-magnetite core and glycidyl methacrylateNN1015840-methylene-bis-acrylamide resin shell were prepared and modified withDA and TA The studied resins showed high adsorptioncapacities towards uranium ions reached 92 and 158mggfor R-1 and R-2 respectively The results revealed that thepseudo-second-order sorption is the predominant mech-anism The amount of U(VI) adsorbed per unit mass ofall resins increased as temperature increased showing theendothermic nature of the sorption process The experimen-tal results from equilibrium experiences were computed byseveral adsorption isotherm models Langmuir FreundlichTemkin and Dubinin-Radushkevich isotherm model Theresults showed that the sorption reaction is more favorableby Langmuir model confirming the monolayer coverage ofuraniumonto the amine resins and indicate the favorability ofthe chemical adsorption processThe positive heat of adsorp-tion indicates that the adsorption process is endothermicThe
10 Journal of Engineering
Table 5 Chemical analysis of granitic samples
Sample Majorconstituent Trace
constituentConcentration
ppm
1
SiO2
735 U 4000AL2O3
128 Th 300Fe2O3
25 Rare earth 270CaO 13 Rb 225Na2O 26 Zr 197
MgO 05 Y 126K2O 24
2
SiO2
735 U 3200AL2O3
138 Th 190Fe2O3
36 Rare earth 270CaO 14 Rb mdashNa2O 06 Zr 400
MgO 05 Y 197K2O 24
3
SiO2
725 U 2700AL2O3
128 Th 260Fe2O3
25 Rare earth 250CaO 13 Rb 437Na2O 39 Zr 284
MgO 05 Y 135K2O 34
Table 6 Results of treatment of the granite samples with the studiedresins
Resin Metal ion Removal efficiency ()Sample 1 Sample 2 Sample 3
R-1U(VI) 93 93 928Fe(III) 26 25 26RE2O3
15 15 15
R-2U(VI) 995 992 99Fe(III) 31 31 31RE2O3
55 80 85
positive value of Δ119878∘ points to increasing of the randomnessdegree at the resinsolution interface during the progress ofsorption process The negative values of Δ119866∘ values confirmthe spontaneous nature of the sorption process
Finally it can be concluded that
(1) the prepared magnetite-cored resins have advantagetoward the filtration process where the magnetiteparticles impart the magnetic properties to the beadsthat allow rapid and easy separation of beads by theapplication of an external magnetic field avoidingsome technical problems arising due to using thetraditional filter papers
(2) the magnetite core allows more spreading of theactive group on the surface of resin particles thatenhance the adsorption efficiency comparing to othernonmagnetite core resins [10]
(3) the prepared resins are recommended as effectiveadsorbate materials regarding separation of uraniumions from their bearing solutions particularly in thepresence of other competitive metal ions
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] O Philippova A Barabanova V Molchanov and A KhokhlovldquoMagnetic polymer beads recent trends and developments insynthetic design and applicationsrdquo European Polymer Journalvol 47 no 4 pp 542ndash559 2011
[2] Q Yuan and R A Williams ldquoLarge scale manufacture ofmagnetic polymer particles using membranes and microfluidicdevicesrdquo China Particuology vol 5 no 1-2 pp 26ndash42 2007
[3] C-Y Chen C-L Chiang and P-C Huang ldquoAdsorptions ofheavy metal ions by a magnetic chelating resin containinghydroxy and iminodiacetate groupsrdquo Separation and Purifica-tion Technology vol 50 no 1 pp 15ndash21 2006
[4] D Horak B Rittich and A Spanova ldquoCarboxyl-functionalizedmagnetic microparticle carrier for isolation and identificationof DNA in dairy productsrdquo Journal of Magnetism and MagneticMaterials vol 311 no 1 pp 249ndash254 2007
[5] AAAtia AMDonia andA E Shahin ldquoStudies on the uptakebehavior of a magnetic Co
3O4-containing resin for Ni(II)
Cu(II) andHg(II) from their aqueous solutionsrdquo Separation andPurification Technology vol 46 no 3 pp 208ndash213 2005
[6] A M Donia A A Atia H A El-Boraey and D H MabroukldquoAdsorption of Ag(I) on glycidyl methacrylateNN1015840-methylenebis-acrylamide chelating resins with embedded iron oxiderdquoSeparation and Purification Technology vol 48 no 3 pp 281ndash287 2006
[7] A M Donia A A Atia H A El-Boraey and D H MabroukldquoUptake studies of copper(II) on glycidyl methacrylate chelat-ing resin containing Fe
2O3particlesrdquo Separation and Purifica-
tion Technology vol 49 no 1 pp 64ndash70 2006[8] A M Donia A A Atia and K Z Elwakeel ldquoSelective sepa-
ration of mercury(II) using magnetic chitosan resin modifiedwith Schiff rsquos base derived from thiourea and glutaraldehyderdquoJournal of Hazardous Materials vol 151 no 2-3 pp 372ndash3792008
[9] K Z Elwakeel and A A Atia ldquoUptake of U(VI) from aqueousmedia by magnetic Schiff rsquos base chitosan compositerdquo Journal ofCleaner Production vol 70 pp 292ndash302 2014
[10] A M Donia A A Atia E M M Moussa A M El-Sherifand M O Abd El-Magied ldquoRemoval of uranium(VI) fromaqueous solutions using glycidyl methacrylate chelating resinsrdquoHydrometallurgy vol 95 no 3-4 pp 183ndash189 2009
[11] Z Marczenko Separation and Spectrophotometric Determina-tion of Elements Ellis Harwood Chichester UK 1986
[12] S A Sadeek M A El-Sayed M M Amine and M O Abd El-Magied ldquoA chelating resin containing trihydroxybenzoic acidas the functional group synthesis and adsorption behavior forTh(IV) and U(VI) ionsrdquo Journal of Radioanalytical and NuclearChemistry vol 299 no 3 pp 1299ndash1306 2014
[13] W Dong and S C Brooks ldquoDetermination of the formationconstants of ternary complexes of uranyl and carbonate with
Journal of Engineering 11
alkaline earth metals (Mg2+ Ca2+ Sr2+ and Ba2+) using anionexchangemethodrdquoEnvironmental ScienceampTechnology vol 40no 15 pp 4689ndash4695 2006
[14] C Xiong X Liu and C Yao ldquoEffect of pH on sorptionfor RE(III) and sorption behaviors of Sm(III) by D152 resinrdquoJournal of Rare Earths vol 26 no 6 pp 851ndash856 2008
[15] A O Dada A P Olalekan A M Olatunya and O DadaldquoLangmuir Freundlich Temkin and Dubinin-Radushkevichisotherms studies of equilibrium sorption of Zn2+ unto phos-phoric acid modified rice huskrdquo Journal of Applied Chemistryvol 3 no 1 pp 38ndash45 2012
[16] V P Mpofu J Addai-Mensah and J Ralston ldquoTemperatureinfluence of nonionic polyethylene oxide and anionic polyacry-lamide on flocculation and dewatering behavior of kaolinitedispersionsrdquo Journal of Colloid and Interface Science vol 271no 1 pp 145ndash156 2004
[17] A U Itodo andHU Itodo ldquoSorption energies estimation usingDubinin-Radushkevich andTemkin adsorption isothermsrdquo LifeScience Journal vol 7 no 4 pp 31ndash39 2010
[18] K Dev R Pathak and G N Rao ldquoSorption behaviour oflanthanum(III) neodymium(III) terbium(III) thorium(IV)and uranium(VI) on Amberlite XAD-4 resin functionalizedwith bicine ligandsrdquo Talanta vol 48 no 3 pp 579ndash584 1999
[19] V K Jain A Handa S S Sait P Shrivastav and Y K AgrawalldquoPre-concentration separation and trace determination of lan-thanum(III) cerium(III) thorium(IV) and uranium(VI) onpolymer supported o-vanillinsemicarbazonerdquo Analytica Chim-ica Acta vol 429 no 2 pp 237ndash246 2001
[20] M Nogami I M Ismail M Yamaguchi and K SuzukildquoSynthesis characterization and some adsorption properties ofTMMA chelating resinrdquo Journal of Solid State Chemistry vol171 no 1-2 pp 353ndash357 2003
[21] P Metilda K Sanghamitra J M Gladis G R K Naiduand T Prasada Rao ldquoAmberlite XAD-4 functionalized withsuccinic acid for the solid phase extractive preconcentrationand separation of uranium(VI)rdquo Talanta vol 65 no 1 pp 192ndash200 2005
[22] DH Phillips B GuD BWatson andC S Parmele ldquoUraniumremoval from contaminated groundwater by synthetic resinsrdquoWater Research vol 42 no 1-2 pp 260ndash268 2008
[23] Y Jung S Kim S-J Park and J M Kim ldquoApplication ofpolymer-modified nanoporous silica to adsorbents of uranylionsrdquo Colloids and Surfaces A vol 313-314 pp 162ndash166 2008
[24] G Tian J Geng Y Jin et al ldquoSorption of uranium(VI) usingoxime-grafted ordered mesoporous carbon CMK-5rdquo Journal ofHazardous Materials vol 190 no 1ndash3 pp 442ndash450 2011
[25] T S Anirudhan J Nima and P L Divya ldquoAdsorption and sep-aration behavior of uranium(VI) by 4-vinylpyridine-grafted-vinyltriethoxysilane-cellulose ion imprinted polymerrdquo Journalof Environmental Chemical Engineering vol 3 no 2 pp 1267ndash1276 2015
[26] N T Tavengwa E Cukrowska and L Chimuka ldquoSynthesis ofbulk ion-imprinted polymers (IIPs) embedded with oleic acidcoated Fe
3O4for selective extraction of hexavalent uraniumrdquo
Water SA vol 40 no 4 pp 623ndash630 2014[27] M Solgy M Taghizadeh and D Ghoddocynejad ldquoAdsorption
of uranium(VI) from sulphate solutions using Amberlite IRA-402 resin equilibrium kinetics and thermodynamics studyrdquoAnnals of Nuclear Energy vol 75 pp 132ndash138 2015
[28] J Li X Yang C Bai et al ldquoA novel benzimidazole-functionalized 2-D COF material synthesis and application as
a selective solid-phase extractant for separation of uraniumrdquoJournal of Colloid and Interface Science vol 437 pp 211ndash2182015
[29] N T Tavengwa E Cukrowska and L Chimuka ldquoSelectiveadsorption of uranium (VI) on NaHCO
3leached composite
120574-methacryloxypropyltrimethoxysilane coated magnetic ion-imprinted polymers prepared by precipitation polymerizationrdquoSouth African Journal of Chemistry vol 68 pp 61ndash68 2015
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
Journal of Engineering 9
3
4
5
6
0 20000 40000 60000
R-1R-2
ln q e
1205762
Figure 11 Dubinin-Radushkevich isotherm model
0
25
50
75
100
0
50
100
150
200
250
0 05 1 15
Adso
rptio
n ca
paci
ty (m
gg)
Solidliquid (mgmL)
Adso
rptio
n effi
cien
cy (
)
R-1 (mgg)R-2 (mgg)R-1 ()R-2 ()
Figure 12 The effect of the solidliquid ratio on the adsorptionefficiency
The values of the apparent energy of adsorption alsodepict chemisorption process
35 SolidLiquid Ratio The effect of the solidliquid ratio onthe adsorption efficiency of the studied resins was achievedusing variable amounts of R-1 and R-2 resins (0025 to 0125 g)in 100mL of the adsorption medium and the results wereshowed in Figure 12 The adsorption efficiency of the resinsincreased with increasing their dose while the adsorptioncapacities decreased This result is reasonable if we considerthat as the higher resin dose in the solution as the higheravailability of active sites for metal ion adsorption
36 Resin Regeneration For desorption studies 05 g of theuranium loaded dry resin with uranium was gently washedwith distilled water to remove any unabsorbed metal ionsand then shaken with 100mL of 01M HNO
3for 30min
and finally the uranium concentration was determined in thefiltrate All the experiments were performed in duplicate withexperimental error plusmn05ndash2 After the uranium elution theresins were regenerated by washing with 1M NaOH solutionfollowed by washing with distilled water hence the resinbecame regenerated and ready for the next use Regenerationefficiency was found to be about 90ndash96 for two resins over3 cycles
It is worth mentioning that using of the eluted resinswithout alkalinewashing failed to adsorbmore uranium ionswhich can be ascribed to the protonation of the amino activegroups that prevent the U(VI) ions adsorption Accordinglytreatment with the alkaline solution converted these proto-nated groups into free ones which have the affinity towardsthe U(VI) ions
37 Application of the Studied Resins for Granite SamplesThree granite rock samples were collected from Gabal Gattarpluton located inNorth EasternDesert of EgyptThe sampleswere crushed and ground to minus200 mesh size and analyzed byconventional wet chemical techniques for their major oxidecompositions as well as by XRF for some trace elements Thechemical analysis of the studied granitic samples is given inTable 5 The granitic samples contain high concentration ofFe2O3(t) Rb Y Nb U and Th and low concentration of Sr
and Ba compared with similar Egyptian granitesFor thework purpose the uranium content in the granitic
samples was selectively leached using nitric acid solution(2M) for 6 hours at 60∘C The reacted slurry was filteredand washed with hot water The obtained filtrate was treatedwith R-1 and R-2 for the uranium separation The uptakeresults of U(VI) ions (Table 6) showed that both the resinsdisplayed higher removal efficiency towards U(VI) relative toother metal ions present in sample solution
4 Conclusion
Magnetic glycidyl methacrylate resin particles with nano-magnetite core and glycidyl methacrylateNN1015840-methylene-bis-acrylamide resin shell were prepared and modified withDA and TA The studied resins showed high adsorptioncapacities towards uranium ions reached 92 and 158mggfor R-1 and R-2 respectively The results revealed that thepseudo-second-order sorption is the predominant mech-anism The amount of U(VI) adsorbed per unit mass ofall resins increased as temperature increased showing theendothermic nature of the sorption process The experimen-tal results from equilibrium experiences were computed byseveral adsorption isotherm models Langmuir FreundlichTemkin and Dubinin-Radushkevich isotherm model Theresults showed that the sorption reaction is more favorableby Langmuir model confirming the monolayer coverage ofuraniumonto the amine resins and indicate the favorability ofthe chemical adsorption processThe positive heat of adsorp-tion indicates that the adsorption process is endothermicThe
10 Journal of Engineering
Table 5 Chemical analysis of granitic samples
Sample Majorconstituent Trace
constituentConcentration
ppm
1
SiO2
735 U 4000AL2O3
128 Th 300Fe2O3
25 Rare earth 270CaO 13 Rb 225Na2O 26 Zr 197
MgO 05 Y 126K2O 24
2
SiO2
735 U 3200AL2O3
138 Th 190Fe2O3
36 Rare earth 270CaO 14 Rb mdashNa2O 06 Zr 400
MgO 05 Y 197K2O 24
3
SiO2
725 U 2700AL2O3
128 Th 260Fe2O3
25 Rare earth 250CaO 13 Rb 437Na2O 39 Zr 284
MgO 05 Y 135K2O 34
Table 6 Results of treatment of the granite samples with the studiedresins
Resin Metal ion Removal efficiency ()Sample 1 Sample 2 Sample 3
R-1U(VI) 93 93 928Fe(III) 26 25 26RE2O3
15 15 15
R-2U(VI) 995 992 99Fe(III) 31 31 31RE2O3
55 80 85
positive value of Δ119878∘ points to increasing of the randomnessdegree at the resinsolution interface during the progress ofsorption process The negative values of Δ119866∘ values confirmthe spontaneous nature of the sorption process
Finally it can be concluded that
(1) the prepared magnetite-cored resins have advantagetoward the filtration process where the magnetiteparticles impart the magnetic properties to the beadsthat allow rapid and easy separation of beads by theapplication of an external magnetic field avoidingsome technical problems arising due to using thetraditional filter papers
(2) the magnetite core allows more spreading of theactive group on the surface of resin particles thatenhance the adsorption efficiency comparing to othernonmagnetite core resins [10]
(3) the prepared resins are recommended as effectiveadsorbate materials regarding separation of uraniumions from their bearing solutions particularly in thepresence of other competitive metal ions
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] O Philippova A Barabanova V Molchanov and A KhokhlovldquoMagnetic polymer beads recent trends and developments insynthetic design and applicationsrdquo European Polymer Journalvol 47 no 4 pp 542ndash559 2011
[2] Q Yuan and R A Williams ldquoLarge scale manufacture ofmagnetic polymer particles using membranes and microfluidicdevicesrdquo China Particuology vol 5 no 1-2 pp 26ndash42 2007
[3] C-Y Chen C-L Chiang and P-C Huang ldquoAdsorptions ofheavy metal ions by a magnetic chelating resin containinghydroxy and iminodiacetate groupsrdquo Separation and Purifica-tion Technology vol 50 no 1 pp 15ndash21 2006
[4] D Horak B Rittich and A Spanova ldquoCarboxyl-functionalizedmagnetic microparticle carrier for isolation and identificationof DNA in dairy productsrdquo Journal of Magnetism and MagneticMaterials vol 311 no 1 pp 249ndash254 2007
[5] AAAtia AMDonia andA E Shahin ldquoStudies on the uptakebehavior of a magnetic Co
3O4-containing resin for Ni(II)
Cu(II) andHg(II) from their aqueous solutionsrdquo Separation andPurification Technology vol 46 no 3 pp 208ndash213 2005
[6] A M Donia A A Atia H A El-Boraey and D H MabroukldquoAdsorption of Ag(I) on glycidyl methacrylateNN1015840-methylenebis-acrylamide chelating resins with embedded iron oxiderdquoSeparation and Purification Technology vol 48 no 3 pp 281ndash287 2006
[7] A M Donia A A Atia H A El-Boraey and D H MabroukldquoUptake studies of copper(II) on glycidyl methacrylate chelat-ing resin containing Fe
2O3particlesrdquo Separation and Purifica-
tion Technology vol 49 no 1 pp 64ndash70 2006[8] A M Donia A A Atia and K Z Elwakeel ldquoSelective sepa-
ration of mercury(II) using magnetic chitosan resin modifiedwith Schiff rsquos base derived from thiourea and glutaraldehyderdquoJournal of Hazardous Materials vol 151 no 2-3 pp 372ndash3792008
[9] K Z Elwakeel and A A Atia ldquoUptake of U(VI) from aqueousmedia by magnetic Schiff rsquos base chitosan compositerdquo Journal ofCleaner Production vol 70 pp 292ndash302 2014
[10] A M Donia A A Atia E M M Moussa A M El-Sherifand M O Abd El-Magied ldquoRemoval of uranium(VI) fromaqueous solutions using glycidyl methacrylate chelating resinsrdquoHydrometallurgy vol 95 no 3-4 pp 183ndash189 2009
[11] Z Marczenko Separation and Spectrophotometric Determina-tion of Elements Ellis Harwood Chichester UK 1986
[12] S A Sadeek M A El-Sayed M M Amine and M O Abd El-Magied ldquoA chelating resin containing trihydroxybenzoic acidas the functional group synthesis and adsorption behavior forTh(IV) and U(VI) ionsrdquo Journal of Radioanalytical and NuclearChemistry vol 299 no 3 pp 1299ndash1306 2014
[13] W Dong and S C Brooks ldquoDetermination of the formationconstants of ternary complexes of uranyl and carbonate with
Journal of Engineering 11
alkaline earth metals (Mg2+ Ca2+ Sr2+ and Ba2+) using anionexchangemethodrdquoEnvironmental ScienceampTechnology vol 40no 15 pp 4689ndash4695 2006
[14] C Xiong X Liu and C Yao ldquoEffect of pH on sorptionfor RE(III) and sorption behaviors of Sm(III) by D152 resinrdquoJournal of Rare Earths vol 26 no 6 pp 851ndash856 2008
[15] A O Dada A P Olalekan A M Olatunya and O DadaldquoLangmuir Freundlich Temkin and Dubinin-Radushkevichisotherms studies of equilibrium sorption of Zn2+ unto phos-phoric acid modified rice huskrdquo Journal of Applied Chemistryvol 3 no 1 pp 38ndash45 2012
[16] V P Mpofu J Addai-Mensah and J Ralston ldquoTemperatureinfluence of nonionic polyethylene oxide and anionic polyacry-lamide on flocculation and dewatering behavior of kaolinitedispersionsrdquo Journal of Colloid and Interface Science vol 271no 1 pp 145ndash156 2004
[17] A U Itodo andHU Itodo ldquoSorption energies estimation usingDubinin-Radushkevich andTemkin adsorption isothermsrdquo LifeScience Journal vol 7 no 4 pp 31ndash39 2010
[18] K Dev R Pathak and G N Rao ldquoSorption behaviour oflanthanum(III) neodymium(III) terbium(III) thorium(IV)and uranium(VI) on Amberlite XAD-4 resin functionalizedwith bicine ligandsrdquo Talanta vol 48 no 3 pp 579ndash584 1999
[19] V K Jain A Handa S S Sait P Shrivastav and Y K AgrawalldquoPre-concentration separation and trace determination of lan-thanum(III) cerium(III) thorium(IV) and uranium(VI) onpolymer supported o-vanillinsemicarbazonerdquo Analytica Chim-ica Acta vol 429 no 2 pp 237ndash246 2001
[20] M Nogami I M Ismail M Yamaguchi and K SuzukildquoSynthesis characterization and some adsorption properties ofTMMA chelating resinrdquo Journal of Solid State Chemistry vol171 no 1-2 pp 353ndash357 2003
[21] P Metilda K Sanghamitra J M Gladis G R K Naiduand T Prasada Rao ldquoAmberlite XAD-4 functionalized withsuccinic acid for the solid phase extractive preconcentrationand separation of uranium(VI)rdquo Talanta vol 65 no 1 pp 192ndash200 2005
[22] DH Phillips B GuD BWatson andC S Parmele ldquoUraniumremoval from contaminated groundwater by synthetic resinsrdquoWater Research vol 42 no 1-2 pp 260ndash268 2008
[23] Y Jung S Kim S-J Park and J M Kim ldquoApplication ofpolymer-modified nanoporous silica to adsorbents of uranylionsrdquo Colloids and Surfaces A vol 313-314 pp 162ndash166 2008
[24] G Tian J Geng Y Jin et al ldquoSorption of uranium(VI) usingoxime-grafted ordered mesoporous carbon CMK-5rdquo Journal ofHazardous Materials vol 190 no 1ndash3 pp 442ndash450 2011
[25] T S Anirudhan J Nima and P L Divya ldquoAdsorption and sep-aration behavior of uranium(VI) by 4-vinylpyridine-grafted-vinyltriethoxysilane-cellulose ion imprinted polymerrdquo Journalof Environmental Chemical Engineering vol 3 no 2 pp 1267ndash1276 2015
[26] N T Tavengwa E Cukrowska and L Chimuka ldquoSynthesis ofbulk ion-imprinted polymers (IIPs) embedded with oleic acidcoated Fe
3O4for selective extraction of hexavalent uraniumrdquo
Water SA vol 40 no 4 pp 623ndash630 2014[27] M Solgy M Taghizadeh and D Ghoddocynejad ldquoAdsorption
of uranium(VI) from sulphate solutions using Amberlite IRA-402 resin equilibrium kinetics and thermodynamics studyrdquoAnnals of Nuclear Energy vol 75 pp 132ndash138 2015
[28] J Li X Yang C Bai et al ldquoA novel benzimidazole-functionalized 2-D COF material synthesis and application as
a selective solid-phase extractant for separation of uraniumrdquoJournal of Colloid and Interface Science vol 437 pp 211ndash2182015
[29] N T Tavengwa E Cukrowska and L Chimuka ldquoSelectiveadsorption of uranium (VI) on NaHCO
3leached composite
120574-methacryloxypropyltrimethoxysilane coated magnetic ion-imprinted polymers prepared by precipitation polymerizationrdquoSouth African Journal of Chemistry vol 68 pp 61ndash68 2015
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
10 Journal of Engineering
Table 5 Chemical analysis of granitic samples
Sample Majorconstituent Trace
constituentConcentration
ppm
1
SiO2
735 U 4000AL2O3
128 Th 300Fe2O3
25 Rare earth 270CaO 13 Rb 225Na2O 26 Zr 197
MgO 05 Y 126K2O 24
2
SiO2
735 U 3200AL2O3
138 Th 190Fe2O3
36 Rare earth 270CaO 14 Rb mdashNa2O 06 Zr 400
MgO 05 Y 197K2O 24
3
SiO2
725 U 2700AL2O3
128 Th 260Fe2O3
25 Rare earth 250CaO 13 Rb 437Na2O 39 Zr 284
MgO 05 Y 135K2O 34
Table 6 Results of treatment of the granite samples with the studiedresins
Resin Metal ion Removal efficiency ()Sample 1 Sample 2 Sample 3
R-1U(VI) 93 93 928Fe(III) 26 25 26RE2O3
15 15 15
R-2U(VI) 995 992 99Fe(III) 31 31 31RE2O3
55 80 85
positive value of Δ119878∘ points to increasing of the randomnessdegree at the resinsolution interface during the progress ofsorption process The negative values of Δ119866∘ values confirmthe spontaneous nature of the sorption process
Finally it can be concluded that
(1) the prepared magnetite-cored resins have advantagetoward the filtration process where the magnetiteparticles impart the magnetic properties to the beadsthat allow rapid and easy separation of beads by theapplication of an external magnetic field avoidingsome technical problems arising due to using thetraditional filter papers
(2) the magnetite core allows more spreading of theactive group on the surface of resin particles thatenhance the adsorption efficiency comparing to othernonmagnetite core resins [10]
(3) the prepared resins are recommended as effectiveadsorbate materials regarding separation of uraniumions from their bearing solutions particularly in thepresence of other competitive metal ions
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] O Philippova A Barabanova V Molchanov and A KhokhlovldquoMagnetic polymer beads recent trends and developments insynthetic design and applicationsrdquo European Polymer Journalvol 47 no 4 pp 542ndash559 2011
[2] Q Yuan and R A Williams ldquoLarge scale manufacture ofmagnetic polymer particles using membranes and microfluidicdevicesrdquo China Particuology vol 5 no 1-2 pp 26ndash42 2007
[3] C-Y Chen C-L Chiang and P-C Huang ldquoAdsorptions ofheavy metal ions by a magnetic chelating resin containinghydroxy and iminodiacetate groupsrdquo Separation and Purifica-tion Technology vol 50 no 1 pp 15ndash21 2006
[4] D Horak B Rittich and A Spanova ldquoCarboxyl-functionalizedmagnetic microparticle carrier for isolation and identificationof DNA in dairy productsrdquo Journal of Magnetism and MagneticMaterials vol 311 no 1 pp 249ndash254 2007
[5] AAAtia AMDonia andA E Shahin ldquoStudies on the uptakebehavior of a magnetic Co
3O4-containing resin for Ni(II)
Cu(II) andHg(II) from their aqueous solutionsrdquo Separation andPurification Technology vol 46 no 3 pp 208ndash213 2005
[6] A M Donia A A Atia H A El-Boraey and D H MabroukldquoAdsorption of Ag(I) on glycidyl methacrylateNN1015840-methylenebis-acrylamide chelating resins with embedded iron oxiderdquoSeparation and Purification Technology vol 48 no 3 pp 281ndash287 2006
[7] A M Donia A A Atia H A El-Boraey and D H MabroukldquoUptake studies of copper(II) on glycidyl methacrylate chelat-ing resin containing Fe
2O3particlesrdquo Separation and Purifica-
tion Technology vol 49 no 1 pp 64ndash70 2006[8] A M Donia A A Atia and K Z Elwakeel ldquoSelective sepa-
ration of mercury(II) using magnetic chitosan resin modifiedwith Schiff rsquos base derived from thiourea and glutaraldehyderdquoJournal of Hazardous Materials vol 151 no 2-3 pp 372ndash3792008
[9] K Z Elwakeel and A A Atia ldquoUptake of U(VI) from aqueousmedia by magnetic Schiff rsquos base chitosan compositerdquo Journal ofCleaner Production vol 70 pp 292ndash302 2014
[10] A M Donia A A Atia E M M Moussa A M El-Sherifand M O Abd El-Magied ldquoRemoval of uranium(VI) fromaqueous solutions using glycidyl methacrylate chelating resinsrdquoHydrometallurgy vol 95 no 3-4 pp 183ndash189 2009
[11] Z Marczenko Separation and Spectrophotometric Determina-tion of Elements Ellis Harwood Chichester UK 1986
[12] S A Sadeek M A El-Sayed M M Amine and M O Abd El-Magied ldquoA chelating resin containing trihydroxybenzoic acidas the functional group synthesis and adsorption behavior forTh(IV) and U(VI) ionsrdquo Journal of Radioanalytical and NuclearChemistry vol 299 no 3 pp 1299ndash1306 2014
[13] W Dong and S C Brooks ldquoDetermination of the formationconstants of ternary complexes of uranyl and carbonate with
Journal of Engineering 11
alkaline earth metals (Mg2+ Ca2+ Sr2+ and Ba2+) using anionexchangemethodrdquoEnvironmental ScienceampTechnology vol 40no 15 pp 4689ndash4695 2006
[14] C Xiong X Liu and C Yao ldquoEffect of pH on sorptionfor RE(III) and sorption behaviors of Sm(III) by D152 resinrdquoJournal of Rare Earths vol 26 no 6 pp 851ndash856 2008
[15] A O Dada A P Olalekan A M Olatunya and O DadaldquoLangmuir Freundlich Temkin and Dubinin-Radushkevichisotherms studies of equilibrium sorption of Zn2+ unto phos-phoric acid modified rice huskrdquo Journal of Applied Chemistryvol 3 no 1 pp 38ndash45 2012
[16] V P Mpofu J Addai-Mensah and J Ralston ldquoTemperatureinfluence of nonionic polyethylene oxide and anionic polyacry-lamide on flocculation and dewatering behavior of kaolinitedispersionsrdquo Journal of Colloid and Interface Science vol 271no 1 pp 145ndash156 2004
[17] A U Itodo andHU Itodo ldquoSorption energies estimation usingDubinin-Radushkevich andTemkin adsorption isothermsrdquo LifeScience Journal vol 7 no 4 pp 31ndash39 2010
[18] K Dev R Pathak and G N Rao ldquoSorption behaviour oflanthanum(III) neodymium(III) terbium(III) thorium(IV)and uranium(VI) on Amberlite XAD-4 resin functionalizedwith bicine ligandsrdquo Talanta vol 48 no 3 pp 579ndash584 1999
[19] V K Jain A Handa S S Sait P Shrivastav and Y K AgrawalldquoPre-concentration separation and trace determination of lan-thanum(III) cerium(III) thorium(IV) and uranium(VI) onpolymer supported o-vanillinsemicarbazonerdquo Analytica Chim-ica Acta vol 429 no 2 pp 237ndash246 2001
[20] M Nogami I M Ismail M Yamaguchi and K SuzukildquoSynthesis characterization and some adsorption properties ofTMMA chelating resinrdquo Journal of Solid State Chemistry vol171 no 1-2 pp 353ndash357 2003
[21] P Metilda K Sanghamitra J M Gladis G R K Naiduand T Prasada Rao ldquoAmberlite XAD-4 functionalized withsuccinic acid for the solid phase extractive preconcentrationand separation of uranium(VI)rdquo Talanta vol 65 no 1 pp 192ndash200 2005
[22] DH Phillips B GuD BWatson andC S Parmele ldquoUraniumremoval from contaminated groundwater by synthetic resinsrdquoWater Research vol 42 no 1-2 pp 260ndash268 2008
[23] Y Jung S Kim S-J Park and J M Kim ldquoApplication ofpolymer-modified nanoporous silica to adsorbents of uranylionsrdquo Colloids and Surfaces A vol 313-314 pp 162ndash166 2008
[24] G Tian J Geng Y Jin et al ldquoSorption of uranium(VI) usingoxime-grafted ordered mesoporous carbon CMK-5rdquo Journal ofHazardous Materials vol 190 no 1ndash3 pp 442ndash450 2011
[25] T S Anirudhan J Nima and P L Divya ldquoAdsorption and sep-aration behavior of uranium(VI) by 4-vinylpyridine-grafted-vinyltriethoxysilane-cellulose ion imprinted polymerrdquo Journalof Environmental Chemical Engineering vol 3 no 2 pp 1267ndash1276 2015
[26] N T Tavengwa E Cukrowska and L Chimuka ldquoSynthesis ofbulk ion-imprinted polymers (IIPs) embedded with oleic acidcoated Fe
3O4for selective extraction of hexavalent uraniumrdquo
Water SA vol 40 no 4 pp 623ndash630 2014[27] M Solgy M Taghizadeh and D Ghoddocynejad ldquoAdsorption
of uranium(VI) from sulphate solutions using Amberlite IRA-402 resin equilibrium kinetics and thermodynamics studyrdquoAnnals of Nuclear Energy vol 75 pp 132ndash138 2015
[28] J Li X Yang C Bai et al ldquoA novel benzimidazole-functionalized 2-D COF material synthesis and application as
a selective solid-phase extractant for separation of uraniumrdquoJournal of Colloid and Interface Science vol 437 pp 211ndash2182015
[29] N T Tavengwa E Cukrowska and L Chimuka ldquoSelectiveadsorption of uranium (VI) on NaHCO
3leached composite
120574-methacryloxypropyltrimethoxysilane coated magnetic ion-imprinted polymers prepared by precipitation polymerizationrdquoSouth African Journal of Chemistry vol 68 pp 61ndash68 2015
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
Journal of Engineering 11
alkaline earth metals (Mg2+ Ca2+ Sr2+ and Ba2+) using anionexchangemethodrdquoEnvironmental ScienceampTechnology vol 40no 15 pp 4689ndash4695 2006
[14] C Xiong X Liu and C Yao ldquoEffect of pH on sorptionfor RE(III) and sorption behaviors of Sm(III) by D152 resinrdquoJournal of Rare Earths vol 26 no 6 pp 851ndash856 2008
[15] A O Dada A P Olalekan A M Olatunya and O DadaldquoLangmuir Freundlich Temkin and Dubinin-Radushkevichisotherms studies of equilibrium sorption of Zn2+ unto phos-phoric acid modified rice huskrdquo Journal of Applied Chemistryvol 3 no 1 pp 38ndash45 2012
[16] V P Mpofu J Addai-Mensah and J Ralston ldquoTemperatureinfluence of nonionic polyethylene oxide and anionic polyacry-lamide on flocculation and dewatering behavior of kaolinitedispersionsrdquo Journal of Colloid and Interface Science vol 271no 1 pp 145ndash156 2004
[17] A U Itodo andHU Itodo ldquoSorption energies estimation usingDubinin-Radushkevich andTemkin adsorption isothermsrdquo LifeScience Journal vol 7 no 4 pp 31ndash39 2010
[18] K Dev R Pathak and G N Rao ldquoSorption behaviour oflanthanum(III) neodymium(III) terbium(III) thorium(IV)and uranium(VI) on Amberlite XAD-4 resin functionalizedwith bicine ligandsrdquo Talanta vol 48 no 3 pp 579ndash584 1999
[19] V K Jain A Handa S S Sait P Shrivastav and Y K AgrawalldquoPre-concentration separation and trace determination of lan-thanum(III) cerium(III) thorium(IV) and uranium(VI) onpolymer supported o-vanillinsemicarbazonerdquo Analytica Chim-ica Acta vol 429 no 2 pp 237ndash246 2001
[20] M Nogami I M Ismail M Yamaguchi and K SuzukildquoSynthesis characterization and some adsorption properties ofTMMA chelating resinrdquo Journal of Solid State Chemistry vol171 no 1-2 pp 353ndash357 2003
[21] P Metilda K Sanghamitra J M Gladis G R K Naiduand T Prasada Rao ldquoAmberlite XAD-4 functionalized withsuccinic acid for the solid phase extractive preconcentrationand separation of uranium(VI)rdquo Talanta vol 65 no 1 pp 192ndash200 2005
[22] DH Phillips B GuD BWatson andC S Parmele ldquoUraniumremoval from contaminated groundwater by synthetic resinsrdquoWater Research vol 42 no 1-2 pp 260ndash268 2008
[23] Y Jung S Kim S-J Park and J M Kim ldquoApplication ofpolymer-modified nanoporous silica to adsorbents of uranylionsrdquo Colloids and Surfaces A vol 313-314 pp 162ndash166 2008
[24] G Tian J Geng Y Jin et al ldquoSorption of uranium(VI) usingoxime-grafted ordered mesoporous carbon CMK-5rdquo Journal ofHazardous Materials vol 190 no 1ndash3 pp 442ndash450 2011
[25] T S Anirudhan J Nima and P L Divya ldquoAdsorption and sep-aration behavior of uranium(VI) by 4-vinylpyridine-grafted-vinyltriethoxysilane-cellulose ion imprinted polymerrdquo Journalof Environmental Chemical Engineering vol 3 no 2 pp 1267ndash1276 2015
[26] N T Tavengwa E Cukrowska and L Chimuka ldquoSynthesis ofbulk ion-imprinted polymers (IIPs) embedded with oleic acidcoated Fe
3O4for selective extraction of hexavalent uraniumrdquo
Water SA vol 40 no 4 pp 623ndash630 2014[27] M Solgy M Taghizadeh and D Ghoddocynejad ldquoAdsorption
of uranium(VI) from sulphate solutions using Amberlite IRA-402 resin equilibrium kinetics and thermodynamics studyrdquoAnnals of Nuclear Energy vol 75 pp 132ndash138 2015
[28] J Li X Yang C Bai et al ldquoA novel benzimidazole-functionalized 2-D COF material synthesis and application as
a selective solid-phase extractant for separation of uraniumrdquoJournal of Colloid and Interface Science vol 437 pp 211ndash2182015
[29] N T Tavengwa E Cukrowska and L Chimuka ldquoSelectiveadsorption of uranium (VI) on NaHCO
3leached composite
120574-methacryloxypropyltrimethoxysilane coated magnetic ion-imprinted polymers prepared by precipitation polymerizationrdquoSouth African Journal of Chemistry vol 68 pp 61ndash68 2015
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of