phragmites karka as a biosorbent for the removal of mercury metal

Research ArticlePhragmites karka as a Biosorbent for the Removal of MercuryMetal Ions from Aqueous Solution Effect of Modification

Muhammad Hamid Raza1 Aqsa Sadiq2 Umar Farooq1 Makshoof Athar1

Tajamal Hussain1 Adnan Mujahid1 and Muhammad Salman1

1 Institute of Chemistry University of the Punjab Lahore 54590 Pakistan2College of Earth and Environmental Sciences University of the Punjab Lahore 54590 Pakistan

Correspondence should be addressed to Umar Farooq umarchempuedupk

Received 3 December 2014 Revised 3 February 2015 Accepted 3 February 2015

Academic Editor Wenshan Guo

Copyright copy 2015 Muhammad Hamid Raza et al This is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

Batch scale studies for the adsorption potential of novel biosorbent Phragmites karka (Trin) in its natural and treated forms wereperformed for removal ofmercury ions from aqueous solutionThe studywas carried out at different parameters to obtain optimumconditions of pH biosorbent dose agitation speed time of contact temperature and initial metal ion concentration To analyzethe suitability of the process and maximum amount of metal uptake Dubinin-Radushkevich (D-R) model Freundlich isothermand Langmuir isotherm were applied The values of 119902max for natural and treated biosorbents were found at 179 and 227mggrespectively The optimum values of contact time and agitation speed were found at 50min and 150 rpm for natural biosorbentwhereas 40min and 100 rpm for treated biosorbent respectively The optimum biosorption capacities were observed at pH 4 andtemperature 313 K for both natural P karka and treated P karka 119877

119871values indicate that comparatively treated P karka was more

feasible for mercury adsorption compared to natural P karka Both pseudo-first-order and pseudo-second-order kinetic modelswere applied and it was found that data fit best to the pseudo-second-order kinetic model Thermodynamic studies indicate thatadsorption process was spontaneous feasible and endothermic

1 Introduction

The generic name Phragmites is attributed to Trinius as theearlier Phragmites Adans is considered a redundant name forSaccharumLinnPhragmites represents a part ofArundo LinnIt is a cosmopolitan genus of four species P karka (Retz)Phragmites australis (Cav) Phragmites japonicus Steud andPhragmites mauritianus Kunth Phragmites australis Trin andP karka Trin are allopatric and are found to be in temperateand tropic species respectively [1 2] P karka (Retz) is alsoknown as Arundo karka (Retz) Arundo roxburghii KunthPhragmites maxima Phragmites nepalensis and Phragmitesroxburghii (Kunth) Steud It is a perennial reed having creep-ing rhizomes Culms are erect up to 15ndash3m high Length andwidth of leaf blades range as 20ndash60 cm or more 8ndash32mmrespectively which are pungent and sometimes stiff Panicles

are 6ndash10 cm wide and 20ndash30 cm long and the lowest node isusually few branched Spikelets are 12ndash18mm long and therhachilla hairs are 6ndash10mm long abundant and silky [3]The fertile lemmas are narrowly lanceolate and 9ndash13mm longThe middle and upper stem internodes of American reed aresmooth shiny and red-brown to dark red-brown during thegrowing season while in common reed (Phragmites australis)middle to upper stem internodes are dull ridged and tan col-ored during the growing season It is a perennial grass abun-dantly found across railway lines and roadsides near streamsand in marshes ponds wetlands barrages swamps andwater headworks inNewGuinea Africa NorthernAustraliaand Asia and is also widely distributed in Pakistan In Pak-istan it is distributed in Punjab andKashmir regions and tem-perate regions of both hemispheres It is said to be poisonousto cattle (Duthie) and is not used as fodder P karka is mostly

Hindawi Publishing CorporationJournal of ChemistryVolume 2015 Article ID 293054 12 pageshttpdxdoiorg1011552015293054

2 Journal of Chemistry

used as weaving material and decoration and for makingmusical instruments It is also an excellent stabilizer oferoding river banks [1ndash3]

In this study biosorption potential of P karka (Trin Retz)Steud locally known as Khagra reed was studied for heavy-metals uptake from aqueous solution in single metal ion sys-tem as novel application Heavy-metals pollution is a world-wide problem as they are nonbiodegradable and hazardous tohuman health and environment due to high bioaccumulationand magnification potential [2ndash7] Lead mercury and cad-mium are known as the three famous pollutants due to theirhigh impact on the environment [8] Natural sources of mer-cury include volcanic action weathering of mercuriferrousrocks degassing from surface water biogenic emissions andnatural forest fires [9] while anthropogenic sources includechemical manufacturing metallurgical and metal finishingindustries pulp and paper industry pharmaceuticals seeddressings fungicides dental preparations thermometerspaints and fluorescent and ultraviolet lamps [9 10] Inhumans symptoms ofmercury poisoning aremalfunctioningof central nervous system visual constriction loss ofmemoryhearing and renal disturbance [11 12] Due to its high toxicityEuropean Union recommended maximum permissible limitof Hg in drinking and wastewater as 0001 and 0005mgLminus1respectively [13 14] According toWorldHealthOrganizationand China guidelines permissible level of inorganic mercuryin drinking water is 10 120583g Lminus1 [15]

The term ldquoBiosorptionrdquo describes the removal of theheavy metals from a solution by nonmetabolically mediatedpassive binding to living or dead biomass [1 16] This processis based on the fact that certain natural materials of biolog-ical origin have property of metal sequestering [17] Depend-ing on origin and physicochemical conditions biosorptioninvolves different processeswhich includemetal ion exchangecoordination complexes covalent linkage to biomass compo-nents and physiologically mediated intracellular uptake [1819] From last two decades it is being considered as one of themost suitable economic and green technologiesThematerialreusability no toxic sludge production low operating costimproved selectivity and compressed operation time forcertain metals are some of its advantages over conventionaltechniques [11 20] Microorganisms fungi algae lichensaquatic macrophytes and animals waste materials and ter-restrial plants in natural and treated and modified forms arenow being used to check their sorption potential by manyresearchers of the world Furthermore chemically treatedbiosorbents including orange peels bagasse pith coconuthusks and polyacrylamide-grafted banana stalks have beenused for the biosorption of mercury ions [21]

The effects of agitation speed biosorbent dose pH initialmetal ion concentration and temperature and contact timeon adsorption potential were studied in this research Char-acteristics of biosorbent were also studied by Fourier trans-form infrared spectroscopy In addition equilibrium studieswere performed by applying Langmuir isotherm Freundlichisotherms and D-R model to calculate 119902max values andsuitability of the sorption process Kinetic studies were per-formed by applying pseudo-first-order and pseudo-second-order kineticsThermodynamics studies were also performedto analyze spontaneity of the biosorption process

2 Material and Methods

21 Raw Biomass Plant biomass selected for biosorptionstudies (P karka Trin) was collected from railway headquar-ters Mughalpura Lahore (25∘5810158402510158401015840N 68∘3810158401510158401015840E) Leavesand stems of the plants were used for sorption studies becausethey are waste materials while its rhizome is used in herbalmedicines

22 Preparation of Biosorbent P karka (Trin) is a long plantwith length about two meters So for ease of washing andhandling it was first manually broken down into four to fivepieces per plantThose pieces were then washed with distilledwater twice in the laboratory to remove all the litter Washedplant biomass was first air dried for one day and thenmanually choppedwith Chinese axe to convert into small sizepieces for ease of oven drying Oven drying was done for 14hours at 90∘C till constant mass was obtained Oven driedplant biomass was ground in a shredder and then passedthrough mesh number 50 of US standard sieves to getbiosorbent of same particle size that is 297120583m

23 Chemical Treatment of Biosorbent Powdered biosorbentwas divided into two parts one was kept in air tight glasscontainer as such in natural form and used for further exper-imentation (named as natural P karka) while second partwas treated according to the method described elsewhere [1]For treatment purpose 200 g of powdered biosorbent wassoaked in solution containing 1000ml ethanol 500mLNaOH (05molL) and 500mL CaCl

2(15molL) for 24

hours [1 11ndash14] After repeated filtration and decantation ofbiosorbent it was first dried in open air and then oven driedto get its constant mass The material was stored in airtightplastic container and named as treated P karka

24 Analytical Instruments and Reagents All chemicals usedwere of pure analytical grade purchased from Sigma AldrichInc Glassware was soaked in 20 (vv) nitric acid for 24hours and then rinsed two to three times using doubledistilled water Mercury stock solution (1000mgL) wasprepared by dissolving specific quantity of mercuric chlorideHgCl2salt in doubly distilled water Working and standard

solutions of mercury were prepared just before use byrequired dilutions of stock solution NaOH (01M) and HCl(01M) solutions were used for pH adjustment of solutions bydigital pHmeter (Iono Lab pH 720) Oven used was of Mem-mert (Germany) and solutions were agitated after additionof biosorbent on orbital shaker (IKA Germany Yellow lineOS 10 basic) Filtrates were analyzed by AAS (Perkin ElmerAnalyst 700 equipped with MHS 15 CVAAS system) Thebandwidth of spectrum was 07 nm for mercury ions isola-tion while 6 mA operating hollow cathode lamp was usedSodium borohydride (2wv) in sodiumhydroxide was usedas reducing agent

25 Batch Biosorption Procedure Biosorption of mercuryHg(II) metal ions on natural and treated plant biomass

Journal of Chemistry 3

(P karka) was studied in batch fashion The effects of tem-perature pH initial metal ion concentration contact timebiosorbent dose and agitation speed on adsorption capacityof biomass were investigated

Batch pH experiments were performed for 200mL solu-tion of Hg(II) ions (10mgL) in Erlenmeyer flask (250mL)with 2 g biosorbent while the pH was varied from 2 to 8The pH of solutions was adjusted initially and not thereafterThe flasks were agitated on orbital shaker at 150 rpm speedfor 30 minutes at 298K temperature After each experimentsolutions were immediately filtered by using Whatman filterpapers of grade 40 and filtrates were analyzed using CVAASSame process was done for other conditions by changing oneparameter and keeping the rest constant

The effect of biosorbent dose on sorption capacity wasdetermined at six different doses in range of 10ndash60 g bykeeping rest of parameters constantThe effect of temperatureon the adsorption capacity of the biosorbent was determinedat different temperatures (ie 20 30 40 and 50∘C) Effectof agitation speed on sorption was studied at 100 150 200250 and 300 rpm For determination of optimum contacttime samples were drawn at regular intervals at 20 30 40 50and 60min Effect of initial metal ion concentration onbiosorption was also studied at six different concentrations inrange of 10ndash60 ppm All experiments were performed intriplicate fashion and their average values were consideredin analysis Percent biosorptive removal and metal uptakecapacity were calculated by the following equations

Biosorptive Removal () =119862119894minus 119862119891

119862119894

times 100

Amount of metal ions adsorbed (119902119890) = (119862

119894minus 119862119891) times119881

119898

(1)

where119862119894(mgL) and119862

119891(mgL) are the initial and final metal

ion concentrations of solution respectively 119881 is the volumeof metal ion solution (L) and119898 is the mass of the biosorbent(g)

3 Results and Discussion

31 FTIR FTIR spectroscopy is used to analyze the chem-ical functional groups on the biosorbent FTIR spectra ofthe natural as well as treated biosorbent were recorded in600ndash4000 cmminus1 range and are shown in Figure 1

The two peaks A and B represent FTIR spectra of naturalP karka and treated P karka respectively Peak (I) of naturalbiosorbent sample at 337056 cmminus1 indicates presence of (O-H) hydroxyl group in cellulose hemicellulose pectin andlignin it is shifted after treatment to 329056 cmminus1 peak (I)Peak (II) at 290094 cmminus1 in natural biosorbent is repre-sentative of stretching vibration of alkanes (C-H) that ismethyl methylene or methoxy group This peak is shifted to294723 cmminus1 in treated biosorbent with greater intensityPeak (III) represents presence of aldehydes group in naturalP karka at 288551 cmminus1 whereas in treated biosorbent peak(III) is observed at 2885 cmminus1 representing nitriles and

T(

) I

I

II

II

III

III

IV

IV

V

V

VI

VI

VII

VII

VIII

VIII

IX

IX XXI

(A)

(B)

(1cm)

Figure 1 FTIR of natural P karka and treated P karka (biosorbents)

alkyne groups Peak (IV) at 173015 cmminus1 represents carbonylgroup (C=O) of aldehydes whereas peak (IV) at treatedbiosorbent is at 2133 cmminus1 representing carbonyl group ofaldehydes and ketones Peak (V) at 163371 cmminus1 indicatespresence of carboxylate group (COOminus) and it is shiftedto 159513 cmminus1 in treated biosorbent Peak (VI) for bothbiosorbents is at 1506 cmminus1 representing N-O (nitro groups)Peak VII is at 14254 cmminus1 which is shifted to 143504 cmminus1 intreated biosorbent and represents presence of (C-H) groupof aliphatic or aromatic hydrocarbons Peaks (IX) in range of1300ndash1000 cmminus1 (12403 and 1163 cmminus1 for natural and treatedbiosorbents resp) are representative of (C-O) stretchingof alcohols (R-OH) and carboxylic acids (RCOOH) Theappearance of peak (IX) at 1163 cmminus1 in treated biosorbentshows presence of aldehydes and aliphatic amines specificallyThe addition of two more peaks (X XI) in treated biosorbentat 1064 cmminus1 and 896 cmminus1 again shows the presence of nitrileand unsaturation in the carbon chain Results confirmed thechanges in some functional groups of treated biosorbent

32 Effect of pH on Biosorption Determination of 119901119867119901119911119888

Heavy metal ions sorption on the surface of biosorbent is apH dependent process which affects the functional groups ofbiosorbent and the metal ions chemistry in solution [22ndash27]As a result pH affects the availability of metal ions in solutionand metal binding sites on biosorbent surfaces As shownin Figure 3 Hg(II) adsorption capacity at pH 3 was03055mg gminus1 and 0338mg gminus1 for natural P karka andtreated P karka respectively At low pH values below 4 com-petition between protons andmetal ions exists for same bind-ing sites hence metal binding capacity decreases [28 29]Different functional groups on plant surface are important forthe sorption of mercury A previous work on parsley statedthat carboxylate groups of plants play amajor role inmercuryions bindings [29] At lower value of pH (pH lt 4) H+ ionsmay bind with negatively charged hydroxyl groups on plantsurfaces or other lone pair carriers groups such as carbonylHence there arises a competition between H+ ions andmetalions in the solutionThe researchers found a similar situationthat occurs in case of caster leaves where the carboxylategroups are considered as attracting sites on leaves [9]Adsorption capacity increased with further increase in pHand reached optimum values of 0510mg gminus1 (801) and0579mg gminus1 (958) at pH 6 and pH 7 for natural P karkaand treated P karka respectively This value is in agreement


15

1

05

minus05

minus1

minus15

minus2

minus25

00 2 4 6 8 10 12

ΔpH

pH

Natural P karkaTreated P karka

Figure 2 Point zero charge (pHpzc) values for the biosorption ofmercury ions on natural P karka and treated P karka (concentration= 10mgL time = 30minutes 119879 = 298K agitation speed = 150 rpmdose of biosorbent = 2 g100mL and pH = 2ndash8)

07

06

05

04

03

02

01

00 2 4 6 8 10

qe

(mg

g)

pH


Figure 3 Effect of pH change on biosorption capacity of naturalP karka and treated P karka (concentration = 10mgL time = 30minutes 119879 = 298K agitation speed = 150 rpm dose of biosorbent =2 g100mL and pH = 2ndash8)

with many previous researchers who have reported optimumbiosorption of mercury by different biomasses at pH 6 ornear values [17 30ndash32] An increase in biosorption levelswith increasing pH can also be explained by relating thebiosorption to the number of available negative charges onthe surfaces Beyond optimumpHvalues decrease in adsorp-tion capacities was observed This is because at high pHsolution has excess number of OHminus ions which enhance theprobability of salt or hydroxide formation with metal ions inthe solution In case of alkali and alkaline earth metal ionsthis probability can be ignored as their hydroxides are solublebut for heavy metal ions like mercury and so forth itcontributes significantly Hence there is a decrease in metalremoval efficiency (Figure 2)

In point of zero charge pHpzc represents the pH whereadsorbent surface becomes electrically neutral Above thepHpzc value surface of biosorbent acquired negative chargewhereas below the pHpzc point surface acquired positivecharge Hence cationic biosorption will be favorable abovethe pHpzc point and anionic biosorption will be optimumbelow the pHpzc point pHpzc was determined for the biosorp-tion of mercury ions on the natural P karka and treated P

05

045

04

035

03

025

020 50 100 150 200 250 300 350

Agitation speed (rpm)

qe

(mg

g)


Figure 4 Effect of agitation speed on adsorption capacity of naturalP karka and treated P karka (concentration = 10mgL time =30 minutes 119879 = 298K agitation speed = 100ndash300 rpm dose ofbiosorbent = 2 g100mL and pH = 6 and 7 for natural P karka andtreated p karka resp)

karka using the method described in [28 33] Figure 2 Thevalues of pHpzc were found at 45 and 5 for natural P karkaand treated P karka respectively (Figure 3)The results are inagreement with the pH values obtained for the same experi-ment showing maximum biosorption at pH 6 and 7 for nat-ural P karka and treated P karka respectively (above pHpzcvalues adsorption of mercury ions is cationic adsorptionFigure 3)

33 Effect of Agitation Speed on Biosorption Shaking speedis important in biosorption process because it increases thechances of interaction between metal ions and biomassAdsorption increases with increase in shaking speed At slowspeed biosorbent settles down and buries many active sitesunder its top layers So only top layer takes part in adsorptionprocess because the under buried layers do not have contactwithmetal ions Figure 4 indicates that maximum adsorptionof Hg(II) ions for natural P karka was 0329mg gminus1 (658)at 150 rpm while for treated P karkamaximum adsorption ofHg(II) attained was 0446mg gminus1 (891) at 100 rpm TreatedP karka has 233 more biosorptive removal capacity thannatural P karka A decrease in adsorption was observedby further increase in shaking speed because at high agita-tion speed random collisions between particles (adsorbate-adsorbate adsorbent-adsorbate and adsorbent-adsorbent)do not provide enough time to heavy metal ions to bindwith surface of the biosorbent [33] Moreover increase inbiosorption capacity in treated biosorbent is due to theaddition of some functional groups which cause increase inthe binding capacity of the material

34 Effect of Dose on Biosorption The effect of biosorbentdose on biosorption efficiency for Hg(II) ions was investi-gated As shown in Figure 5 the maximummetal uptake wasfound to be 0107mgg (893) for natural biomass at concen-tration of 1 g100mL and for treated biomass was 0398mgg(932) at 1 g100mL The uptake capacities decreased athigher dosages The above facts can be illustrated as a


0 1 2 3 4 5 6 7

Dose (g)

04504

035030250201501005

0

qe

(mg

g)


Figure 5 Effect of biosorbent dose on adsorption capacity of naturalP karka and treated P karka (concentration = 10mgL time = 30minutes 119879 = 298K agitation speed = 150 and 100 rpm natural Pkarka and treated p karka resp dose of biosorbent = 1ndash6 g100mLand pH = 6 and 7 for natural P karka and treated p karka resp)

result of partial aggregation that occurs at high doses ofbiomass resulting in decreasing the number of active siteson the surfaces of biomass [22 23] A further increase inbiomass concentration over optimum dose does not leadto appreciable improvement in biosorptive metal removaldue to the saturation of the adsorbent surface with metalions and the establishment of equilibrium between the ionsremaining nonadsorbed in the solution and which bound tothe adsorbent

35 Effect of Contact Time on Biosorption Time of contact isalso one of the most important parameters that helps to usebiosorbent successfully in practical and the rapid biosorptionapplication [27ndash32 34 35] Time needed for metal sorptionhelps to determine the amount of solutions that can be treatedand impacts on the process selection and its design [26]Figure 6 indicates the biosorption capacity of natural P karkaand treated P karka versus time for Hg(II) ions removalfrom aqueous solution The maximum sorption capacity ofHg(II) was attained in first 20min for both natural P karkaand treated P karka After that there was slight increase insorption with time and sorption equilibrium was reachedin 50min (04365mg gminus1 873) and 40min (04545mg gminus1909) for natural P karka and treated P karka respectivelyMost of themercury ions sorptionwas attained in first 20minthat may be due to availability of more sorption sites inthe beginning of experiment Initially with increase in timemetal ions find more adsorptionbinding sites hence metaladsorption amount of metal ions increased The maximumamount of metal ions adsorbed at 50min and system reachedequilibrium At equilibrium state maximum adsorption ofmetal ions illustrated the covering of maximum binding siteswith metal ions Hence rate of adsorption may decrease toa constant value with further increase in time as in case ofnatural P karka which is due to complete coverage of activesites to the surface of biosorbent and increase in rate ofdesorption with respect to time as well which is in agreementwith some previous researches on different biosorbents [3ndash5 27ndash32 34]

045

04

035

03

025

02

015

01

005

017 27 37 47 57

t (min)

qe

(mg

g)


Figure 6 Effect of contact time on adsorption capacity of naturalP karka and treated P karka (concentration = 10mgL time = 20ndash60 minutes 119879 = 298K agitation speed = 150 and 100 rpm naturalP karka and treated p karka resp dose of biosorbent = 1 g100mLand pH = 6 and 7 for natural P karka and treated p karka resp)

36 Kinetic Studies of Adsorption Rate of metal uptake bya particular adsorbent is calculated from kinetic studiesand it is important for design of biosorption process [36]Comparison of calculated and experimental uptake (119902

119890) data

and shape of graph helps to find which model fits best to thebiosorption process Moreover value of coefficient of deter-mination (1198772) above 098 is an indication of model suitability[37] The pseudo-first-order (Lagergren kinetic model)describes sorption of solid or liquid systems based on solidcapacity

Δ119902119905

Δ119905= 1198701(119902119890minus 119902119905) (2)

where 119902119905and 119902

119890(mgg) are adsorption capacities at time 119905

and at equilibrium respectively and 1198961is the first-order rate

constant (minminus1) Linear form of pseudo-first-order kineticsmodel is written by the following equations

ln (119902119890minus 119902119905) = ln 119902

119890minus 1198701119905 (3)

Consider pseudo-second-order rate kinetics by

Δ119902119905

Δ119905= 1198702(119902119890minus 119902119905)2 (4)

where 1198962is constant for second-order rate (mg gminus1minminus1) Its

linear form is written by the following equation

119905

119902119905

=1

11987021199021198902+119905

119902119890

(5)

The rate-controlling mechanism may be varying duringthe adsorption process There are three possible mechanismsthat may be cropping up Diffusion process or mass transferthrough external surfaces controls the early stage of thisprocessThen there is a reaction or a stage of constant rate andthen it finally reached diffusion stage after that biosorptionprocess slows down significantly [12] Data shows 1198772 values


Table 1 Parameters of pseudo-first-order and pseudo-second-order kinetic models for the biosorption of mercury ions on the surface ofnatural P karka and treated P karka

Biosorbenttype

119902exp(mgg)

Pseudo-first-order kinetics Pseudo-second-order kinetics119902cal

(mgg)1198961

(minminus1) 1198772 119902cal

(mgg)1198962

(gmgminus1minminus1) 1198772

NaturalP karka 0436 0079 minus00308 0502 0453 065 0994

TreatedP karka 0454 0013 minus00283 0972 0456 747 0999

0

minus05

minus1

minus15

minus2

minus25

minus3

log(q

eminusqt)

0 20 40 60 80

Time (min)


(a)

160

140

120

100

80

60

40

20

0

tq

0 10 20 30 40 50 60 70

t (min)


(b)

Figure 7 (a) Pseudo-first-order rate kinetics of Hg(II) for natural P karka and treated P karka (b) Pseudo-second-order rate kinetics ofHg(II) for natural P karka and treated P karka (concentration = 10mgL time = 20ndash60 minutes 119879 = 298K agitation speed = 150 and100 rpm natural P karka and treated p karka resp dose of biosorbent = 1 g100mL and pH = 6 and 7 for natural P karka and treated pkarka resp)

for pseudo-first-order as 0502 and 0972 while for pseudo-second-order 1198772 values are 0994 and 0999 for natural Pkarka and treated P karka respectively (Table 1) So forpseudo-second-order kinetic values of 1198772 for both natural pkarka and treated P karka are in agreement as 1198772 gt 098The experimental metal uptake values are also much closerto the values calculated from pseudo-second-order modelHence the pseudo-first-order kinetics is more deviated fromexperimental values as compared to pseudo-second-orderkineticsThese results revealed that the pseudo-second-ordermechanism is overpowering and chemisorptionmight be therate-limiting step that controls the biosorption process [3839]Theplots of pseudo-first-order and pseudo-second-orderkinetic models are shown in Figure 7

37 Effect of Initial Concentration of Hg(II) on BiosorptionFactor of initial metal ion concentration is important fordetermining the types of effluents that can be treated withbiosorbent Figure 8 shows that metal uptake capacity of thebiosorbent increased with increase in initial metal ion con-centration while it decreased in percentage removal of metal

ions for both naturalP karka and treated P karka Adsorptioncapacity (119902

119890) ranged from 0439 and 0449mg of Hg(II)g

of biosorbent for initial concentration 10 ppm to 17685 and2169mg of Hg(II)g of biosorbent for initial concentration60 ppm for natural and treated biosorbents respectively Theresults gave evidence of the great ability of material to removemercury ions from solutions [40 41]

38 Adsorption Study of Isotherms Adsorption isotherms areimportant for developing an equation which is true represen-tative of the adsorption data andhelp to design the adsorptionprocess Mostly Langmuir isotherm Freundlich isothermand D-R model were applied to the data According toLangmuir isotherm monolayer adsorption occurs on ahomogeneous surface of adsorbent and no interaction isfound between adsorbed molecules on surface of sorbent[42]

119902119890=119902max1198871198621198901 + 119887119862

119890

(6)


0 20 40 60 80

Ci

25

2

15

1

05

0

qe

(mg

g)


(a)

25

2

15

1

05

0

1q

0 05 1 15

1Cf


(b)

Figure 8 (a) Effect of initial metal ion concentration on adsorption capacity of natural P karka and treated P karka (b) Langmuir adsorptionisotherm for natural P karka and treated P karka (concentration = 10ndash60mgL time = 50 and 40 minutes for natural P karka and treated pkarka resp 119879 = 298K agitation speed = 150 and 100 rpm natural P karka and treated p karka resp dose of biosorbent = 1 g100mL andpH = 6 and 7 for natural P karka and treated p karka resp)

where 119902119890(mgg) is metal uptake capacity at equilibrium 119902max

(mgg) is maximum uptake capacity 119887 (Lmg) is Langmuirconstant and 119862

119890(mgL) is concentration of adsorbate at

equilibriumThe linear form of the Langmuir isotherm is

119862119890

119902119890

=119862119890

119902max+1

119887119902max (7)

Feasibility and shape of Langmuir isotherm are calculated byfollowing equation of equilibrium parameter [43]

119877119871=1

1 + 119887119862119890

(8)

Values of 119877119871show that Langmuir isotherm is not favorable

if 119877119871gt 1 linear if 119877

119871= 1 favorable if 0 lt 119877

119871lt 1 and

irreversible if119877119871= 0 [44] All values of119877

119871for natural P karka

and treated P karka lie between 0 and 1 which meansLangmuir isotherm is favourable for both types of biomass

According to the Freundlich isotherm adsorption is amultilayer process and occurs on heterogeneous surfaces [42](10)

119902119890= 119870119891119862119890

1119899 (9)

where 119896 and 1119899 are Freundlich constants Linear form ofFreundlich equation is

log 119902119890= log119870

119891+1

119899log119862119890 (10)

Dubinin-Radushkevich model is used for estimation ofporosity of the biomass and adsorption mechanism basedon the potential theory assuming heterogeneous surfaceThelinear form of (D-R) isotherm model is

ln 119902119890= ln 119902max minus 120573120598

2 (11)

where 120573 is a constant representing the mean free energy ofbiosorption permole of the biosorbate (mol2 kJ2) 119902max is thetheoretical saturation capacity of biosorbent (mg gminus1) and 120598 isthe Polanyi potential which can be calculated by

120598 = 119877119879 ln(1 + 1119862119890

) (12)

where 119879 (K) is the absolute temperature and 119877 (Jmolminus1 Kminus1)is the gas constant Hence by plotting ln 119902

119890versus 1205982 it is

possible to calculate the value of 119902max from the intercept andthe value of120573 by the slopeThe plots of Langmuir Freundlichand D-R models are shown in Figures 8(b) 9(a) and 9(b)respectively The biosorption mean free energy 119864

119904(kJmol) is

calculated as follows [45]

119864119904=1

radic2120573 (13)

Table 2 shows the different parameters calculated fromLangmuir Freundlich and D-R equations for both naturalP karka and treated P karka biomass The values of 119902max arecalculated as 1787 and 2268mgg for natural P karka andtreated P karka respectively The values of correlation factor(1198772) values for Langmuir isotherm are 0978 and 0991 whichshows good fit of the model to both types of biosorbentsHence it shows homogeneous distribution of active sites onthe surface of biosorbent [22ndash27] The 119902max value is greaterthan a number of reported materials (Table 4)

The slope and intercept of Freundlichmodel were used tocalculate the constant indicative of relative adsorption capac-ity 119896119891and factor 119899 and that indicative of adsorption intensity

The value of 119899 tells about favorability of adsorption processAdsorption is said to be better if 119899 is in the range of 2ndash10


Table 2 Langmuir isotherm Freundlich isotherm and D-R model parameters for the biosorption of mercury ions on the surface of naturalP karka and treated P karka

Biosorbent material Langmuir isotherm Freundlich isothermD-R

(Dubinin-Radushkevich)model

Natural P karka

119910 = 21175119909 + 05594 119910 = 04506119909 minus 03675 119910 = minus5119864 minus 07119909 + 031351198772 = 0978 119877

2 = 0987 1198772 = 08373

119887 (Lmg) = 0264 119899 = 2219 119902119898(mgg) = 136

119902max (mgg) = 1787 119870119891= 0429 119864

119904(kJmol) = 100

119877119871= (0274ndash0059) 1119899 = 0451

Treated P karka


2 = 0996 1198772 = 07853

119887 (Lmg) = 0235 119899 = 1729 119902119898(mgg) = 158

119902max (mgg) = 2268 119870119891= 0439 119864

119904(kJmol) = 1118

119877119871= (0298ndash0066) 1119899 = 0578

04

03

02

01

0

minus04

minus03

minus02

minus01

logqe

0 05 1 15

log Ce


(a)

10 2 3

08

06

04

02

0

minus02

minus04

minus06

minus08

minus1

lnqe

1205982 (millions)


(b)

Figure 9 (a) Freundlich adsorption isotherm for natural P karka and treated P karka (b) Dubinin-Radushkevish (D-R) model fornatural Pkarka and treated P karka (concentration = 10ndash60mgL time = 50 and 40 minutes for natural P karka and treated p karka resp 119879 = 298Kagitation speed = 150 and 100 rpm natural P karka and treated p karka resp dose of biosorbent = 1 g100mL and pH = 6 and 7 for naturalP karka and treated p karka resp)

good if in range of 1-2 and average if below 1 Here naturaland treated biosorbents have value of 119899 2219 and 1729respectively This is an indication of better adsorption fornatural biosorbent and good for treated biosorbent Thevalues of coefficient of approximation (1198772) were 0991 and0996 for natural and treated biosorbents respectively thatpointed out a good fit of Freundlich model [24 27ndash29]

The slope and intercept of D-R model (Equation (12))are used to calculate maximum adsorption capacity and 119902max(mgg) was 136mgg and 158mgg respectively for naturalP karka and treated P karkaThese values are not comparablewith experimental values Moreover the values of coefficientof approximation (1198772) are 08373 and 07853 respectively fornatural and treated biosorbents which indicate data is not

fit to the D-R model for both types of biosorbents as com-pared to Langmuir and Freundlich isotherms The values ofadsorption energy are calculated to be 10 kJmol and118 kJmol for natural and treated biosorbents respectivelyThese values are below 8 which indicate physical nature ofadsorption Biosorption process may be chemisorption if 8 lt119864119904lt 16 and physisorption for 119864

119904lt 8 kJmol [27ndash32]

39 Effect of Temperature on Adsorption of Hg(II) Studyof temperature is an important parameter for all energydependent mechanisms as in metal biosorption which ismostly physicochemical in nature [31] Economic suitabilityof any process is always based on energy efficient process


048

046

044

042

04

038

036

034

032

03

qe

(mg

g)

290 300 310 320 330

Temperature (K)


(a)

290 300 310 320 330

Temperature (K)

Linear (natural P karka)Linear (treated P karka)

0

minus1000

minus2000

minus3000

minus4000

minus5000

minus6000

minus7000

ΔG∘

(b)

Figure 10 (a) Effect of temperature on adsorption capacity of natural P karka and treated P karka (b)Thermodynamics studies for natural Pkarka and treated P karka (concentration = 10mgL time = 50 and 40minutes for natural P karka and treated p karka resp 119879 = 298ndash328Kagitation speed = 150 and 100 rpm natural P karka and treated p karka resp dose of biosorbent = 1 g100mL and pH = 6 and 7 for naturalP karka and treated p karka resp)

Figure 10(a) shows effect of temperature on Hg(II) sorptioncapacity of natural P karka and treated P karka at a tem-perature range 293ndash323K Optimum removal capacity wasobtained at 313 K for both types of biosorbents that is04545mg gminus1 and 046mg gminus1 respectively Increase of tem-perature beyond optimum value that is 40∘C leads to adecreased in metal uptake

310 Thermodynamics Thermodynamics parameters of bio-sorption process are calculated by studying effect of temper-ature on the sorption process Values of Gibbs free energychange (Δ119866∘) entropy change (Δ119878∘) and enthalpy change(Δ119867∘) change with temperature [46] Gibbs free energychange is calculated to determine feasibility and spontaneityof the biosorption process by (12)

Δ119866∘= minus119877119879 ln119870

119889 (14)

where Δ119866∘ (kJmol) is Gibbs free energy change 119877 isuniversal gas constant (83145 Jmol K) and119870

119889is equilibrium

constant (119870119889= 119862119900minus119862119890119862119890) The value of Δ119867∘ (kJmol) gives

information about the endothermic or exothermic nature ofthe process while Δ119878∘ (JmolK) indicates whether sorptionprocess is ordered or random Both parameters were calcu-lated from the following equation

Δ119866∘= Δ119867

∘minus 119879Δ119878

∘ (15)

Energy and entropy factors are considered to determinewhich processes will occur spontaneously Negative value of

Table 3Values of thermodynamic parameters for the biosorption ofmercury ions on the surface of natural P karka and treated P karka

Biosorbenttype

Temperature(K)

Δ119878

(Jmolminus1 Kminus1)Δ119867

(kJmolminus1)Δ119866

(kJmolminus1)

NaturalP karka

293

+10169 +26688

minus3058303 minus3648313 minus6237323 minus5584

TreatedP karka

293

+9462 +24034


Δ119866∘ indicates that the reaction is spontaneousThe linear plot

between temperature and Gibbrsquos free energy change (Δ119866∘)gives the enthalpy change (Δ119867∘) from intercept and entropychange (Δ119878∘) from slope of (13)The values of enthalpy changewere found to be +26688 and +24034 kJmol and entropychange as +1016 and +9462 Jmol K for natural P karka andtreated P karka respectively

Negative values of Δ119866∘ indicate that sorption processof mercury is spontaneous and feasible for both naturalbiosorbent and treated biosorbent [47] Increasing trend infeasibility of biosorption process is observed up to 40∘Cafterwards spontaneity and feasibility of process decreased byincreasing temperature to 50∘C Positive values of Δ119867∘


Table 4 A comparison of mercury metal ions adsorbed by different biosorbents

Serial number Type of biosorbent Amount of mercury ions absorbed Reference1 Spent rootlets 0248mmolg [48]2 Saw dust 0042mmolg [49]3 Bamboo pulp 0046mmolg [49]4 Jute 0038mmolg [49]5 Ground-up tree fern 0132mmolg [50]6 Lemma minor 0138mmolg [16]7 Garlic powder 0650mmolg [51]8 Rasped pith sago residue 0001mmolg [52]9 Natural P karka 00089mmolg Present study10 Treated P karka 0113mmolg Present study

indicate that reaction is endothermic while negative values ofΔ119878∘ means there is very less randomness in sorption process

at solidliquid interface (Table 3)

4 Conclusion

Current study on sorption and desorption behavior of naturalP karka and treated P karka (Trin) indicates that its Hg(II)uptake capacity is 179 and 227mgg respectively Sorptionprocess fits Langmuir and Freundlich models and followspseudo-second-order rate kinetics Thermodynamic studiesshow that the sorption process is spontaneous and endother-mic Studies indicate that P karaoke can be used effectivelyfor treatment ofHg(II) loaded effluents and treated absorbenteffectively increases the metal sorption capacity

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

References

[1] A Zehra and M A Khan ldquoComparative effect of NaCl andsea salt on germination of halophytic grass Phragmites karka atdifferent temperature regimesrdquo Pakistan Journal of Botany vol39 no 5 pp 1681ndash1694 2007

[2] J-Z Chen X-C Tao J Xu T Zhang and Z-L Liu ldquoBiosorp-tion of lead cadmium andmercury by immobilizedMicrocystisaeruginosa in a columnrdquo Process Biochemistry vol 40 no 12pp 3675ndash3679 2005

[3] M Horsfall Jr and A I Spiff ldquoEffect of metal ion concentrationon the biosorption of Pb2+ and Cd2+ by Caladium bicolor (wildcocoyam)rdquo African Journal of Biotechnology vol 4 no 2 pp191ndash196 2005

[4] J C Igwe and A A Abia ldquoMaize cob and husk as adsorbentsfor the removal of heavy metals from waste waterrdquoThe PhysicalScientist vol 2 no 1 pp 83ndash92 2003

[5] J PlazaMViera EDonati andEGuibal ldquoBiosorption ofmer-cury byMacrocystis pyrifera and Undaria pinnatifida influenceof zinc cadmiumandnickelrdquo Journal of Environmental Sciencesvol 23 no 11 pp 1778ndash1786 2011

[6] SW Al Rmalli A A Dahmani MM Abuein and A A GlezaldquoBiosorption of mercury from aqueous solutions by powdered

leaves of castor tree (Ricinus communis L)rdquo Journal of Haz-ardous Materials vol 152 no 3 pp 955ndash959 2008

[7] F E El-Nady andMM Atta ldquoToxicity and bioaccumulation ofheavy metals to some marine biota from the Egyptian coastalwatersrdquo Journal of Environmental Science and Health Part Avol 31 no 7 pp 1529ndash1545 1996

[8] K M Paknikar A V Pethkar and P R Puranik ldquoBioreme-diation of metalliferous wastes and products using inactivatedmicrobial biomassrdquo Indian Journal of Biotechnology vol 2 no3 pp 426ndash443 2003

[9] B Volesky ldquoAdvances in biosorption of metals selection ofbiomass typesrdquo FEMS Microbiology Reviews vol 14 no 4 pp291ndash302 1994

[10] M Tuzen A Sari D Mendil and M Soylak ldquoBiosorptiveremoval of mercury(II) from aqueous solution using lichen(Xanthoparmelia conspersa) biomass kinetic and equilibriumstudiesrdquo Journal of Hazardous Materials vol 169 no 1ndash3 pp263ndash270 2009

[11] J C Igwe E C Nwokennaya and A A Abia ldquoThe role of pHin heavy metal detoxification by biosorption from aqueoussolutions containing chelating agentsrdquo African Journal ofBiotechnology vol 4 no 10 pp 1109ndash1112 2005


[13] H Yavuz A Denizli H Gungunes M Safarikova and ISafarik ldquoBiosorption of mercury on magnetically modifiedyeast cellsrdquo Separation and Purification Technology vol 52 no2 pp 253ndash260 2006

[14] I B Rae SWGibb and S Lu ldquoBiosorption ofHg fromaqueoussolutions by crab carapacerdquo Journal of HazardousMaterials vol164 no 2-3 pp 1601ndash1604 2009

[15] A Sari and M Tuzen ldquoRemoval of mercury(II) from aque-ous solution using moss (Drepanocladus revolvens) biomassequilibrium thermodynamic and kinetic studiesrdquo Journal ofHazardous Materials vol 171 no 1ndash3 pp 500ndash507 2009

[16] S-X Li Z Feng-Ying H Yang and N Jian-Cong ldquoThoroughremoval of inorganic and organic mercury from aqueoussolutions by adsorption on Lemna minor powderrdquo Journal ofHazardous Materials vol 186 no 1 pp 423ndash429 2011

[17] Y Kacar C Arpa S Tan A Denizli O Genc and M Y ArıcaldquoBiosorption of Hg(II) and Cd(II) from aqueous solutionscomparison of biosorptive capacity of alginate and immobilized


live and heat inactivated Phanerochaete chrysosporiumrdquo ProcessBiochemistry vol 37 no 6 pp 601ndash610 2002

[18] G Bayramoglu I Tuzun G Celik M Yilmaz and M YArica ldquoBiosorption of mercury(II) cadmium(II) and lead(II)ions from aqueous system by microalgae Chlamydomonasreinhardtii immobilized in alginate beadsrdquo International Journalof Mineral Processing vol 81 no 1 pp 35ndash43 2006

[19] M Y Arıca G Bayramoglu M Yılmaz S Bektas and O GencldquoBiosorption of Hg2+ Cd2+ and Zn2+ by Ca-alginate andimmobilized wood-rotting fungus Funalia trogiirdquo Journal ofHazardous Materials vol 109 no 1ndash3 pp 191ndash199 2004

[20] G Bayramoglu and M Y Arıca ldquoRemoval of heavy mer-cury(II) cadmium(II) and zinc(II) metal ions by live and heatinactivated Lentinus edodes pelletsrdquo Chemical Engineering Jour-nal vol 143 no 1ndash3 pp 133ndash140 2008

[21] V T P Vinod R B Sashidhar N Sivaprasad et al ldquoBioreme-diation of mercury (II) from aqueous solution by gum karaya(Sterculia urens) a natural hydrocolloidrdquoDesalination vol 272no 1ndash3 pp 270ndash277 2011

[22] U Shafique A Ijaz M Salman et al ldquoRemoval of arsenic fromwater using pine leavesrdquo Journal of the Taiwan Institute ofChemical Engineers vol 43 no 2 pp 256ndash263 2012

[23] O Genc Y Yalcınkaya E Buyuktuncel A Denizli M Y Arıcaand S Bektas ldquoUranium recovery by immobilized and driedpowdered biomass characterization and comparisonrdquo Interna-tional Journal of Mineral Processing vol 68 no 1ndash4 pp 93ndash1072003

[24] E W Wilde and J R Benemann ldquoBioremoval of heavy metalsby the use of microalgaerdquo Biotechnology Advances vol 11 no 4pp 781ndash812 1993

[25] P X Sheng Y P Ting J P Chen and LHong ldquoSorption of leadcopper cadmium zinc and nickel by marine algal biomasscharacterization of biosorptive capacity and investigation ofmechanismsrdquo Journal of Colloid and Interface Science vol 275no 1 pp 131ndash141 2004

[26] G Bayramoglu and M Y Arıca ldquoEthylenediamine graftedpoly(glycidylmethacrylate-co-methylmethacrylate) adsorbentfor removal of chromate anionsrdquo Separation and PurificationTechnology vol 45 no 3 pp 192ndash199 2005

[27] J Wase and C F Forster Biosorbents for Metal Ions Taylor ampFrancis London UK 1995

[28] M F Benedetti C J Milne D G Kinninburg W H VanRiemsddijk and L K Koopal ldquoMetal ion binding to humicsubstances application of the non-ideal competitive adsorptionmodelrdquo Environmental Science amp Technology vol 29 no 2 pp446ndash457 1995

[29] E Fourest and B Volesky ldquoAlginate properties and heavymetal biosorption by marine algaerdquo Applied Biochemistry andBiotechnology vol 67 no 3 pp 215ndash226 1997

[30] M Amini H Younesi N Bahramifar et al ldquoApplication ofresponse surfacemethodology for optimization of lead biosorp-tion in an aqueous solution by Aspergillus nigerrdquo Journal ofHazardous Materials vol 154 no 1ndash3 pp 694ndash702 2008

[31] B S Inbaraj and N Sulochana ldquoMercury adsorption on acarbon sorbent derived from fruit shell of Terminalia catappardquoJournal of Hazardous Materials vol 133 no 1ndash3 pp 283ndash2902006

[32] Y Zeroual A Moutaouakkil F Z Dzairi et al ldquoBiosorption ofmercury from aqueous solution by Ulva lactuca biomassrdquoBioresource Technology vol 90 no 3 pp 349ndash351 2003

[33] N-C Feng and X-Y Guo ldquoCharacterization of adsorptivecapacity and mechanisms on adsorption of copper lead andzinc bymodified orange peelrdquoTransactions ofNonferrousMetalsSociety of China vol 22 no 5 pp 1224ndash1231 2012

[34] S Ilhan C F Iscen N Caner and I Kiran ldquoBiosorption poten-tial of dried Penicillium restrictum for Reactive Orange 122isotherm kinetic and thermodynamic studiesrdquo Journal ofChemical Technology and Biotechnology vol 83 no 4 pp 569ndash575 2008

[35] F Kargi and S Cikla ldquoZinc (II) ion recovery by biosorption ontopowdered waste sludge (PWS) effects of operating conditionsrdquoJournal of Chemical Technology and Biotechnology vol 81 no10 pp 1661ndash1668 2006

[36] B Volesky and Z R Holan ldquoBiosorption of heavy metalsrdquoBiotechnology Progress vol 11 no 3 pp 235ndash250 1995

[37] SM Al-Garni ldquoBiosorption of lead byGram-ve capsulated andnon-capsulated bacteriardquo Water SA vol 31 no 3 pp 345ndash3502005

[38] S J Allen Q Gan R Matthews and P A Johnson ldquoKineticmodeling of the adsorption of basic dyes by kudzurdquo Journal ofColloid and Interface Science vol 286 no 1 pp 101ndash109 2005

[39] S Tunali T Akar A S Ozcan I Kiran and A Ozcan ldquoEqui-librium and kinetics of biosorption of lead(II) from aqueoussolutions by Cephalosporium aphidicolardquo Separation and Purifi-cation Technology vol 47 no 3 pp 105ndash112 2006

[40] DKarunasagar J ArunachalamK Rashmi JNaveena LavanyaLatha and P M Mohan ldquoBiosorption of inorganic and methylmercury by a biosorbent from Aspergillus nigerrdquoWorld Journalof Microbiology and Biotechnology vol 19 no 3 pp 291ndash2952003

[41] C Green-Ruiz ldquoMercury(II) removal from aqueous solutionsby nonviable Bacillus sp from a tropical estuaryrdquo BioresourceTechnology vol 97 no 15 pp 1907ndash1911 2006

[42] U Farooq J A Kozinski M A Khan and M Athar ldquoBiosorp-tion of heavy metal ions using wheat based biosorbentsmdashareview of the recent literaturerdquo Bioresource Technology vol 101no 14 pp 5043ndash5053 2010

[43] G McKay H S Blair and J R Gardner ldquoAdsorption of dyes onchitin I Equilibrium studiesrdquo Journal of Applied PolymerScience vol 27 no 8 pp 3043ndash3057 1982

[44] K R Hall L C Eagleton A Acrivos and T Vermeulen ldquoPore-and solid-diffusion kinetics in fixed-bed adsorption underconstant-pattern conditionsrdquo Industrial and Engineering Chem-istry Fundamentals vol 5 no 2 pp 212ndash219 1966

[45] Y Khambhaty K Mody S Basha and B Jha ldquoPseudo-second-order kinetic models for the sorption of Hg(II) onto deadbiomass of marine Aspergillus niger Comparison of linear andnon-linear methodsrdquo Colloids and Surfaces A Physicochemicaland Engineering Aspects vol 328 no 1ndash3 pp 40ndash43 2008

[46] S Karthikeyan R Balasubramanian and C S P Iyer ldquoEvalu-ation of the marine algae Ulva fasciata and Sargassum sp forthe biosorption of Cu(II) from aqueous solutionsrdquo BioresourceTechnology vol 98 no 2 pp 452ndash455 2007

[47] W Zou H Bai S Gao and K Li ldquoCharacterization of modifiedsawdust kinetic and equilibrium study about methylene blueadsorption in batch moderdquo Korean Journal of Chemical Engi-neering vol 30 no 1 pp 111ndash122 2013

[48] Y Zeroual A Moutaouakkil F Z Dzairi et al ldquoBiosorptionof mercury from aqueous solution by Ulva lactuca biomassrdquoBioresource Technology vol 90 no 3 pp 349ndash351 2003


[49] S R Shukla and V D Sakhardande ldquoColumn studies on metalion removal by dyed cellulosic materialsrdquo Journal of AppliedPolymer Science vol 44 no 5 pp 903ndash910 1992

[50] Y S Ho and C-C Wang ldquoSorption equilibrium of mercuryonto ground-up tree fernrdquo Journal of Hazardous Materials vol156 no 1ndash3 pp 398ndash404 2008

[51] Y Eom J H Won J-Y Ryu and T G Lee ldquoBiosorption ofmercury(II) ions from aqueous solution by garlic (Alliumsativum L) powderrdquo Korean Journal of Chemical Engineeringvol 28 no 6 pp 1439ndash1443 2011

[52] N Saman K Johari S S Tien and H Mat ldquoRemoval of Hg(II)and CH

3Hg(I) using rasped pith sago residue biosorbentrdquo

CLEANmdashSoil Air Water vol 42 no 11 pp 1541ndash1548 2014

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


Journal of


Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


used as weaving material and decoration and for makingmusical instruments It is also an excellent stabilizer oferoding river banks [1ndash3]

In this study biosorption potential of P karka (Trin Retz)Steud locally known as Khagra reed was studied for heavy-metals uptake from aqueous solution in single metal ion sys-tem as novel application Heavy-metals pollution is a world-wide problem as they are nonbiodegradable and hazardous tohuman health and environment due to high bioaccumulationand magnification potential [2ndash7] Lead mercury and cad-mium are known as the three famous pollutants due to theirhigh impact on the environment [8] Natural sources of mer-cury include volcanic action weathering of mercuriferrousrocks degassing from surface water biogenic emissions andnatural forest fires [9] while anthropogenic sources includechemical manufacturing metallurgical and metal finishingindustries pulp and paper industry pharmaceuticals seeddressings fungicides dental preparations thermometerspaints and fluorescent and ultraviolet lamps [9 10] Inhumans symptoms ofmercury poisoning aremalfunctioningof central nervous system visual constriction loss ofmemoryhearing and renal disturbance [11 12] Due to its high toxicityEuropean Union recommended maximum permissible limitof Hg in drinking and wastewater as 0001 and 0005mgLminus1respectively [13 14] According toWorldHealthOrganizationand China guidelines permissible level of inorganic mercuryin drinking water is 10 120583g Lminus1 [15]

The term ldquoBiosorptionrdquo describes the removal of theheavy metals from a solution by nonmetabolically mediatedpassive binding to living or dead biomass [1 16] This processis based on the fact that certain natural materials of biolog-ical origin have property of metal sequestering [17] Depend-ing on origin and physicochemical conditions biosorptioninvolves different processeswhich includemetal ion exchangecoordination complexes covalent linkage to biomass compo-nents and physiologically mediated intracellular uptake [1819] From last two decades it is being considered as one of themost suitable economic and green technologiesThematerialreusability no toxic sludge production low operating costimproved selectivity and compressed operation time forcertain metals are some of its advantages over conventionaltechniques [11 20] Microorganisms fungi algae lichensaquatic macrophytes and animals waste materials and ter-restrial plants in natural and treated and modified forms arenow being used to check their sorption potential by manyresearchers of the world Furthermore chemically treatedbiosorbents including orange peels bagasse pith coconuthusks and polyacrylamide-grafted banana stalks have beenused for the biosorption of mercury ions [21]

The effects of agitation speed biosorbent dose pH initialmetal ion concentration and temperature and contact timeon adsorption potential were studied in this research Char-acteristics of biosorbent were also studied by Fourier trans-form infrared spectroscopy In addition equilibrium studieswere performed by applying Langmuir isotherm Freundlichisotherms and D-R model to calculate 119902max values andsuitability of the sorption process Kinetic studies were per-formed by applying pseudo-first-order and pseudo-second-order kineticsThermodynamics studies were also performedto analyze spontaneity of the biosorption process

2 Material and Methods

21 Raw Biomass Plant biomass selected for biosorptionstudies (P karka Trin) was collected from railway headquar-ters Mughalpura Lahore (25∘5810158402510158401015840N 68∘3810158401510158401015840E) Leavesand stems of the plants were used for sorption studies becausethey are waste materials while its rhizome is used in herbalmedicines

22 Preparation of Biosorbent P karka (Trin) is a long plantwith length about two meters So for ease of washing andhandling it was first manually broken down into four to fivepieces per plantThose pieces were then washed with distilledwater twice in the laboratory to remove all the litter Washedplant biomass was first air dried for one day and thenmanually choppedwith Chinese axe to convert into small sizepieces for ease of oven drying Oven drying was done for 14hours at 90∘C till constant mass was obtained Oven driedplant biomass was ground in a shredder and then passedthrough mesh number 50 of US standard sieves to getbiosorbent of same particle size that is 297120583m

23 Chemical Treatment of Biosorbent Powdered biosorbentwas divided into two parts one was kept in air tight glasscontainer as such in natural form and used for further exper-imentation (named as natural P karka) while second partwas treated according to the method described elsewhere [1]For treatment purpose 200 g of powdered biosorbent wassoaked in solution containing 1000ml ethanol 500mLNaOH (05molL) and 500mL CaCl

2(15molL) for 24

hours [1 11ndash14] After repeated filtration and decantation ofbiosorbent it was first dried in open air and then oven driedto get its constant mass The material was stored in airtightplastic container and named as treated P karka

24 Analytical Instruments and Reagents All chemicals usedwere of pure analytical grade purchased from Sigma AldrichInc Glassware was soaked in 20 (vv) nitric acid for 24hours and then rinsed two to three times using doubledistilled water Mercury stock solution (1000mgL) wasprepared by dissolving specific quantity of mercuric chlorideHgCl2salt in doubly distilled water Working and standard

solutions of mercury were prepared just before use byrequired dilutions of stock solution NaOH (01M) and HCl(01M) solutions were used for pH adjustment of solutions bydigital pHmeter (Iono Lab pH 720) Oven used was of Mem-mert (Germany) and solutions were agitated after additionof biosorbent on orbital shaker (IKA Germany Yellow lineOS 10 basic) Filtrates were analyzed by AAS (Perkin ElmerAnalyst 700 equipped with MHS 15 CVAAS system) Thebandwidth of spectrum was 07 nm for mercury ions isola-tion while 6 mA operating hollow cathode lamp was usedSodium borohydride (2wv) in sodiumhydroxide was usedas reducing agent

25 Batch Biosorption Procedure Biosorption of mercuryHg(II) metal ions on natural and treated plant biomass






119862119894

times 100


119894minus 119862119891) times119881

119898

(1)

where119862119894(mgL) and119862






T(

) I

I

II

II

III

III

IV

IV

V

V

VI

VI

VII

VII

VIII

VIII

IX

IX XXI

(A)

(B)

(1cm)






15

1

05

minus05

minus1

minus15

minus2

minus25

00 2 4 6 8 10 12

ΔpH

pH



07

06

05

04

03

02

01

00 2 4 6 8 10

qe

(mg

g)

pH





05

045

04

035

03

025

020 50 100 150 200 250 300 350


qe

(mg

g)







0 1 2 3 4 5 6 7

Dose (g)

04504

035030250201501005

0

qe

(mg

g)





045

04

035

03

025

02

015

01

005

017 27 37 47 57

t (min)

qe

(mg

g)




119890) data


Δ119902119905

Δ119905= 1198701(119902119890minus 119902119905) (2)

where 119902119905and 119902




ln (119902119890minus 119902119905) = ln 119902

119890minus 1198701119905 (3)


Δ119902119905

Δ119905= 1198702(119902119890minus 119902119905)2 (4)



119905

119902119905

=1

11987021199021198902+119905

119902119890

(5)




Biosorbenttype

119902exp(mgg)


(mgg)1198961

(minminus1) 1198772 119902cal

(mgg)1198962




0

minus05

minus1

minus15

minus2

minus25

minus3

log(q

eminusqt)

0 20 40 60 80

Time (min)


(a)

160

140

120

100

80

60

40

20

0

tq

0 10 20 30 40 50 60 70

t (min)


(b)








119902119890=119902max1198871198621198901 + 119887119862

119890

(6)


0 20 40 60 80

Ci

25

2

15

1

05

0

qe

(mg

g)


(a)

25

2

15

1

05

0

1q

0 05 1 15

1Cf


(b)






119862119890

119902119890

=119862119890

119902max+1

119887119902max (7)


119877119871=1

1 + 119887119862119890

(8)


if 119877119871gt 1 linear if 119877

119871= 1 favorable if 0 lt 119877

119871lt 1 and





119902119890= 119870119891119862119890

1119899 (9)


log 119902119890= log119870

119891+1

119899log119862119890 (10)


ln 119902119890= ln 119902max minus 120573120598

2 (11)


120598 = 119877119879 ln(1 + 1119862119890

) (12)


119890versus 1205982 it is


119904(kJmol) is


119864119904=1

radic2120573 (13)








Natural P karka


2 = 0987 1198772 = 08373

119887 (Lmg) = 0264 119899 = 2219 119902119898(mgg) = 136

119902max (mgg) = 1787 119870119891= 0429 119864

119904(kJmol) = 100

119877119871= (0274ndash0059) 1119899 = 0451

Treated P karka


2 = 0996 1198772 = 07853

119887 (Lmg) = 0235 119899 = 1729 119902119898(mgg) = 158

119902max (mgg) = 2268 119870119891= 0439 119864

119904(kJmol) = 1118

119877119871= (0298ndash0066) 1119899 = 0578

04

03

02

01

0

minus04

minus03

minus02

minus01

logqe

0 05 1 15

log Ce


(a)

10 2 3

08

06

04

02

0

minus02

minus04

minus06

minus08

minus1

lnqe

1205982 (millions)


(b)








048

046

044

042

04

038

036

034

032

03

qe

(mg

g)

290 300 310 320 330

Temperature (K)


(a)

290 300 310 320 330

Temperature (K)


0

minus1000

minus2000

minus3000

minus4000

minus5000

minus6000

minus7000

ΔG∘

(b)




Δ119866∘= minus119877119879 ln119870

119889 (14)





Δ119866∘= Δ119867

∘minus 119879Δ119878

∘ (15)



Biosorbenttype

Temperature(K)

Δ119878



(kJmolminus1)

NaturalP karka

293

+10169 +26688


TreatedP karka

293

+9462 +24034










4 Conclusion




References




































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of






119862119894

times 100


119894minus 119862119891) times119881

119898

(1)

where119862119894(mgL) and119862






T(

) I

I

II

II

III

III

IV

IV

V

V

VI

VI

VII

VII

VIII

VIII

IX

IX XXI

(A)

(B)

(1cm)






15

1

05

minus05

minus1

minus15

minus2

minus25

00 2 4 6 8 10 12

ΔpH

pH



07

06

05

04

03

02

01

00 2 4 6 8 10

qe

(mg

g)

pH





05

045

04

035

03

025

020 50 100 150 200 250 300 350


qe

(mg

g)







0 1 2 3 4 5 6 7

Dose (g)

04504

035030250201501005

0

qe

(mg

g)





045

04

035

03

025

02

015

01

005

017 27 37 47 57

t (min)

qe

(mg

g)




119890) data


Δ119902119905

Δ119905= 1198701(119902119890minus 119902119905) (2)

where 119902119905and 119902




ln (119902119890minus 119902119905) = ln 119902

119890minus 1198701119905 (3)


Δ119902119905

Δ119905= 1198702(119902119890minus 119902119905)2 (4)



119905

119902119905

=1

11987021199021198902+119905

119902119890

(5)




Biosorbenttype

119902exp(mgg)


(mgg)1198961

(minminus1) 1198772 119902cal

(mgg)1198962




0

minus05

minus1

minus15

minus2

minus25

minus3

log(q

eminusqt)

0 20 40 60 80

Time (min)


(a)

160

140

120

100

80

60

40

20

0

tq

0 10 20 30 40 50 60 70

t (min)


(b)








119902119890=119902max1198871198621198901 + 119887119862

119890

(6)


0 20 40 60 80

Ci

25

2

15

1

05

0

qe

(mg

g)


(a)

25

2

15

1

05

0

1q

0 05 1 15

1Cf


(b)






119862119890

119902119890

=119862119890

119902max+1

119887119902max (7)


119877119871=1

1 + 119887119862119890

(8)


if 119877119871gt 1 linear if 119877

119871= 1 favorable if 0 lt 119877

119871lt 1 and





119902119890= 119870119891119862119890

1119899 (9)


log 119902119890= log119870

119891+1

119899log119862119890 (10)


ln 119902119890= ln 119902max minus 120573120598

2 (11)


120598 = 119877119879 ln(1 + 1119862119890

) (12)


119890versus 1205982 it is


119904(kJmol) is


119864119904=1

radic2120573 (13)








Natural P karka


2 = 0987 1198772 = 08373

119887 (Lmg) = 0264 119899 = 2219 119902119898(mgg) = 136

119902max (mgg) = 1787 119870119891= 0429 119864

119904(kJmol) = 100

119877119871= (0274ndash0059) 1119899 = 0451

Treated P karka


2 = 0996 1198772 = 07853

119887 (Lmg) = 0235 119899 = 1729 119902119898(mgg) = 158

119902max (mgg) = 2268 119870119891= 0439 119864

119904(kJmol) = 1118

119877119871= (0298ndash0066) 1119899 = 0578

04

03

02

01

0

minus04

minus03

minus02

minus01

logqe

0 05 1 15

log Ce


(a)

10 2 3

08

06

04

02

0

minus02

minus04

minus06

minus08

minus1

lnqe

1205982 (millions)


(b)








048

046

044

042

04

038

036

034

032

03

qe

(mg

g)

290 300 310 320 330

Temperature (K)


(a)

290 300 310 320 330

Temperature (K)


0

minus1000

minus2000

minus3000

minus4000

minus5000

minus6000

minus7000

ΔG∘

(b)




Δ119866∘= minus119877119879 ln119870

119889 (14)





Δ119866∘= Δ119867

∘minus 119879Δ119878

∘ (15)



Biosorbenttype

Temperature(K)

Δ119878



(kJmolminus1)

NaturalP karka

293

+10169 +26688


TreatedP karka

293

+9462 +24034










4 Conclusion




References




































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


15

1

05

minus05

minus1

minus15

minus2

minus25

00 2 4 6 8 10 12

ΔpH

pH



07

06

05

04

03

02

01

00 2 4 6 8 10

qe

(mg

g)

pH





05

045

04

035

03

025

020 50 100 150 200 250 300 350


qe

(mg

g)







0 1 2 3 4 5 6 7

Dose (g)

04504

035030250201501005

0

qe

(mg

g)





045

04

035

03

025

02

015

01

005

017 27 37 47 57

t (min)

qe

(mg

g)




119890) data


Δ119902119905

Δ119905= 1198701(119902119890minus 119902119905) (2)

where 119902119905and 119902




ln (119902119890minus 119902119905) = ln 119902

119890minus 1198701119905 (3)


Δ119902119905

Δ119905= 1198702(119902119890minus 119902119905)2 (4)



119905

119902119905

=1

11987021199021198902+119905

119902119890

(5)




Biosorbenttype

119902exp(mgg)


(mgg)1198961

(minminus1) 1198772 119902cal

(mgg)1198962




0

minus05

minus1

minus15

minus2

minus25

minus3

log(q

eminusqt)

0 20 40 60 80

Time (min)


(a)

160

140

120

100

80

60

40

20

0

tq

0 10 20 30 40 50 60 70

t (min)


(b)








119902119890=119902max1198871198621198901 + 119887119862

119890

(6)


0 20 40 60 80

Ci

25

2

15

1

05

0

qe

(mg

g)


(a)

25

2

15

1

05

0

1q

0 05 1 15

1Cf


(b)






119862119890

119902119890

=119862119890

119902max+1

119887119902max (7)


119877119871=1

1 + 119887119862119890

(8)


if 119877119871gt 1 linear if 119877

119871= 1 favorable if 0 lt 119877

119871lt 1 and





119902119890= 119870119891119862119890

1119899 (9)


log 119902119890= log119870

119891+1

119899log119862119890 (10)


ln 119902119890= ln 119902max minus 120573120598

2 (11)


120598 = 119877119879 ln(1 + 1119862119890

) (12)


119890versus 1205982 it is


119904(kJmol) is


119864119904=1

radic2120573 (13)








Natural P karka


2 = 0987 1198772 = 08373

119887 (Lmg) = 0264 119899 = 2219 119902119898(mgg) = 136

119902max (mgg) = 1787 119870119891= 0429 119864

119904(kJmol) = 100

119877119871= (0274ndash0059) 1119899 = 0451

Treated P karka


2 = 0996 1198772 = 07853

119887 (Lmg) = 0235 119899 = 1729 119902119898(mgg) = 158

119902max (mgg) = 2268 119870119891= 0439 119864

119904(kJmol) = 1118

119877119871= (0298ndash0066) 1119899 = 0578

04

03

02

01

0

minus04

minus03

minus02

minus01

logqe

0 05 1 15

log Ce


(a)

10 2 3

08

06

04

02

0

minus02

minus04

minus06

minus08

minus1

lnqe

1205982 (millions)


(b)








048

046

044

042

04

038

036

034

032

03

qe

(mg

g)

290 300 310 320 330

Temperature (K)


(a)

290 300 310 320 330

Temperature (K)


0

minus1000

minus2000

minus3000

minus4000

minus5000

minus6000

minus7000

ΔG∘

(b)




Δ119866∘= minus119877119879 ln119870

119889 (14)





Δ119866∘= Δ119867

∘minus 119879Δ119878

∘ (15)



Biosorbenttype

Temperature(K)

Δ119878



(kJmolminus1)

NaturalP karka

293

+10169 +26688


TreatedP karka

293

+9462 +24034










4 Conclusion




References




































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


0 1 2 3 4 5 6 7

Dose (g)

04504

035030250201501005

0

qe

(mg

g)





045

04

035

03

025

02

015

01

005

017 27 37 47 57

t (min)

qe

(mg

g)




119890) data


Δ119902119905

Δ119905= 1198701(119902119890minus 119902119905) (2)

where 119902119905and 119902




ln (119902119890minus 119902119905) = ln 119902

119890minus 1198701119905 (3)


Δ119902119905

Δ119905= 1198702(119902119890minus 119902119905)2 (4)



119905

119902119905

=1

11987021199021198902+119905

119902119890

(5)




Biosorbenttype

119902exp(mgg)


(mgg)1198961

(minminus1) 1198772 119902cal

(mgg)1198962




0

minus05

minus1

minus15

minus2

minus25

minus3

log(q

eminusqt)

0 20 40 60 80

Time (min)


(a)

160

140

120

100

80

60

40

20

0

tq

0 10 20 30 40 50 60 70

t (min)


(b)








119902119890=119902max1198871198621198901 + 119887119862

119890

(6)


0 20 40 60 80

Ci

25

2

15

1

05

0

qe

(mg

g)


(a)

25

2

15

1

05

0

1q

0 05 1 15

1Cf


(b)






119862119890

119902119890

=119862119890

119902max+1

119887119902max (7)


119877119871=1

1 + 119887119862119890

(8)


if 119877119871gt 1 linear if 119877

119871= 1 favorable if 0 lt 119877

119871lt 1 and





119902119890= 119870119891119862119890

1119899 (9)


log 119902119890= log119870

119891+1

119899log119862119890 (10)


ln 119902119890= ln 119902max minus 120573120598

2 (11)


120598 = 119877119879 ln(1 + 1119862119890

) (12)


119890versus 1205982 it is


119904(kJmol) is


119864119904=1

radic2120573 (13)








Natural P karka


2 = 0987 1198772 = 08373

119887 (Lmg) = 0264 119899 = 2219 119902119898(mgg) = 136

119902max (mgg) = 1787 119870119891= 0429 119864

119904(kJmol) = 100

119877119871= (0274ndash0059) 1119899 = 0451

Treated P karka


2 = 0996 1198772 = 07853

119887 (Lmg) = 0235 119899 = 1729 119902119898(mgg) = 158

119902max (mgg) = 2268 119870119891= 0439 119864

119904(kJmol) = 1118

119877119871= (0298ndash0066) 1119899 = 0578

04

03

02

01

0

minus04

minus03

minus02

minus01

logqe

0 05 1 15

log Ce


(a)

10 2 3

08

06

04

02

0

minus02

minus04

minus06

minus08

minus1

lnqe

1205982 (millions)


(b)








048

046

044

042

04

038

036

034

032

03

qe

(mg

g)

290 300 310 320 330

Temperature (K)


(a)

290 300 310 320 330

Temperature (K)


0

minus1000

minus2000

minus3000

minus4000

minus5000

minus6000

minus7000

ΔG∘

(b)




Δ119866∘= minus119877119879 ln119870

119889 (14)





Δ119866∘= Δ119867

∘minus 119879Δ119878

∘ (15)



Biosorbenttype

Temperature(K)

Δ119878



(kJmolminus1)

NaturalP karka

293

+10169 +26688


TreatedP karka

293

+9462 +24034










4 Conclusion




References




































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



Biosorbenttype

119902exp(mgg)


(mgg)1198961

(minminus1) 1198772 119902cal

(mgg)1198962




0

minus05

minus1

minus15

minus2

minus25

minus3

log(q

eminusqt)

0 20 40 60 80

Time (min)


(a)

160

140

120

100

80

60

40

20

0

tq

0 10 20 30 40 50 60 70

t (min)


(b)








119902119890=119902max1198871198621198901 + 119887119862

119890

(6)


0 20 40 60 80

Ci

25

2

15

1

05

0

qe

(mg

g)


(a)

25

2

15

1

05

0

1q

0 05 1 15

1Cf


(b)






119862119890

119902119890

=119862119890

119902max+1

119887119902max (7)


119877119871=1

1 + 119887119862119890

(8)


if 119877119871gt 1 linear if 119877

119871= 1 favorable if 0 lt 119877

119871lt 1 and





119902119890= 119870119891119862119890

1119899 (9)


log 119902119890= log119870

119891+1

119899log119862119890 (10)


ln 119902119890= ln 119902max minus 120573120598

2 (11)


120598 = 119877119879 ln(1 + 1119862119890

) (12)


119890versus 1205982 it is


119904(kJmol) is


119864119904=1

radic2120573 (13)








Natural P karka


2 = 0987 1198772 = 08373

119887 (Lmg) = 0264 119899 = 2219 119902119898(mgg) = 136

119902max (mgg) = 1787 119870119891= 0429 119864

119904(kJmol) = 100

119877119871= (0274ndash0059) 1119899 = 0451

Treated P karka


2 = 0996 1198772 = 07853

119887 (Lmg) = 0235 119899 = 1729 119902119898(mgg) = 158

119902max (mgg) = 2268 119870119891= 0439 119864

119904(kJmol) = 1118

119877119871= (0298ndash0066) 1119899 = 0578

04

03

02

01

0

minus04

minus03

minus02

minus01

logqe

0 05 1 15

log Ce


(a)

10 2 3

08

06

04

02

0

minus02

minus04

minus06

minus08

minus1

lnqe

1205982 (millions)


(b)








048

046

044

042

04

038

036

034

032

03

qe

(mg

g)

290 300 310 320 330

Temperature (K)


(a)

290 300 310 320 330

Temperature (K)


0

minus1000

minus2000

minus3000

minus4000

minus5000

minus6000

minus7000

ΔG∘

(b)




Δ119866∘= minus119877119879 ln119870

119889 (14)





Δ119866∘= Δ119867

∘minus 119879Δ119878

∘ (15)



Biosorbenttype

Temperature(K)

Δ119878



(kJmolminus1)

NaturalP karka

293

+10169 +26688


TreatedP karka

293

+9462 +24034










4 Conclusion




References




































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


0 20 40 60 80

Ci

25

2

15

1

05

0

qe

(mg

g)


(a)

25

2

15

1

05

0

1q

0 05 1 15

1Cf


(b)






119862119890

119902119890

=119862119890

119902max+1

119887119902max (7)


119877119871=1

1 + 119887119862119890

(8)


if 119877119871gt 1 linear if 119877

119871= 1 favorable if 0 lt 119877

119871lt 1 and





119902119890= 119870119891119862119890

1119899 (9)


log 119902119890= log119870

119891+1

119899log119862119890 (10)


ln 119902119890= ln 119902max minus 120573120598

2 (11)


120598 = 119877119879 ln(1 + 1119862119890

) (12)


119890versus 1205982 it is


119904(kJmol) is


119864119904=1

radic2120573 (13)








Natural P karka


2 = 0987 1198772 = 08373

119887 (Lmg) = 0264 119899 = 2219 119902119898(mgg) = 136

119902max (mgg) = 1787 119870119891= 0429 119864

119904(kJmol) = 100

119877119871= (0274ndash0059) 1119899 = 0451

Treated P karka


2 = 0996 1198772 = 07853

119887 (Lmg) = 0235 119899 = 1729 119902119898(mgg) = 158

119902max (mgg) = 2268 119870119891= 0439 119864

119904(kJmol) = 1118

119877119871= (0298ndash0066) 1119899 = 0578

04

03

02

01

0

minus04

minus03

minus02

minus01

logqe

0 05 1 15

log Ce


(a)

10 2 3

08

06

04

02

0

minus02

minus04

minus06

minus08

minus1

lnqe

1205982 (millions)


(b)








048

046

044

042

04

038

036

034

032

03

qe

(mg

g)

290 300 310 320 330

Temperature (K)


(a)

290 300 310 320 330

Temperature (K)


0

minus1000

minus2000

minus3000

minus4000

minus5000

minus6000

minus7000

ΔG∘

(b)




Δ119866∘= minus119877119879 ln119870

119889 (14)





Δ119866∘= Δ119867

∘minus 119879Δ119878

∘ (15)



Biosorbenttype

Temperature(K)

Δ119878



(kJmolminus1)

NaturalP karka

293

+10169 +26688


TreatedP karka

293

+9462 +24034










4 Conclusion




References




































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of





Natural P karka


2 = 0987 1198772 = 08373

119887 (Lmg) = 0264 119899 = 2219 119902119898(mgg) = 136

119902max (mgg) = 1787 119870119891= 0429 119864

119904(kJmol) = 100

119877119871= (0274ndash0059) 1119899 = 0451

Treated P karka


2 = 0996 1198772 = 07853

119887 (Lmg) = 0235 119899 = 1729 119902119898(mgg) = 158

119902max (mgg) = 2268 119870119891= 0439 119864

119904(kJmol) = 1118

119877119871= (0298ndash0066) 1119899 = 0578

04

03

02

01

0

minus04

minus03

minus02

minus01

logqe

0 05 1 15

log Ce


(a)

10 2 3

08

06

04

02

0

minus02

minus04

minus06

minus08

minus1

lnqe

1205982 (millions)


(b)








048

046

044

042

04

038

036

034

032

03

qe

(mg

g)

290 300 310 320 330

Temperature (K)


(a)

290 300 310 320 330

Temperature (K)


0

minus1000

minus2000

minus3000

minus4000

minus5000

minus6000

minus7000

ΔG∘

(b)




Δ119866∘= minus119877119879 ln119870

119889 (14)





Δ119866∘= Δ119867

∘minus 119879Δ119878

∘ (15)



Biosorbenttype

Temperature(K)

Δ119878



(kJmolminus1)

NaturalP karka

293

+10169 +26688


TreatedP karka

293

+9462 +24034










4 Conclusion




References




































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


048

046

044

042

04

038

036

034

032

03

qe

(mg

g)

290 300 310 320 330

Temperature (K)


(a)

290 300 310 320 330

Temperature (K)


0

minus1000

minus2000

minus3000

minus4000

minus5000

minus6000

minus7000

ΔG∘

(b)




Δ119866∘= minus119877119879 ln119870

119889 (14)





Δ119866∘= Δ119867

∘minus 119879Δ119878

∘ (15)



Biosorbenttype

Temperature(K)

Δ119878



(kJmolminus1)

NaturalP karka

293

+10169 +26688


TreatedP karka

293

+9462 +24034










4 Conclusion




References




































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of






4 Conclusion




References




































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


















































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

phragmites karka as a biosorbent for the removal of mercury metal

Documents