Journ al of Scienti fic & Industri al Research Vol. 61. March 2002. pp 208-2 18

Removal of Phenol Pollutants from Aqueous Solutions Using Various Adsorbents D K Singh* and Bhavana Sri vastava

Department of Chemistry. Harcourt Butler Technological Ins titu te, Kanpur. 208 002. India

Received: 19 September 200 I: accepted: 03 December 200 I

The review aims at providi ng study concerned with the application of conventional and non-convent ional adsorbents fo r the removal of phenols. The data presented are mainly based on laboratory studies and show potenti al ad"ant ages for treatment of phenol bearing was tewater by adsorpti on on non-conventi onal adsorbents.

Introduction

Phenol and phenoli c compounds in wastewaters are hazardous pollutan ts whi ch appear in almost all chemica l and petrochemi cal effluents from industries such as, iron -steel. coke, petroleum, pesti cides, in secticides , pharmaceuticals, wood preserving chem icals, and paper and pul p industries. Reported average phenolic concentrations for some of the ind ustri al wastewaters1 are given in Table I . Phenolic compounds, especia ll y, chl orinated, may be li fe threatenin g to humans even at low concentrati ons. The World Hea lth Organi zati on (WHO) includes nox ious substances fo r human health , some phenolic compounds with a max imum admissible concentrati on in dri nking water of 200 mg/L for 2,4,6- trichl orophenol, 9 mg/L fo r pentachl orophenol, I 0 mg/L for 2- chl orophenol and 40 mg/L for 2,4-dichl orophenol. The Envi ronmental Protecti on Agency (US-EPA) includes in the Federal Register Lis t eleven substituted phenols known as hazardous fo r human health and assign them a maximum admi ss ibl e concentrati on range of 60 -400 mg/L in relati on to their toxicity degree2

. The permi ss ible limit for phenolic concentrati ons in industri al effluents before di schargin g into municipal sewers and surface waters are 1-5 mg/eA_

Di scharge of phenolic wastes may cau se seri ous probl em as they impart carbolic odour to the water course and can be tox ic to fi sh and human beings5

.

Some phenolic compounds have been found to accelerate tumour formation ,cancer, and mutati on6

*Author for correspondence

Chl orinated phenols are of greater environmental concern because of their hi gher tox ictt/ and wide di stributi on due to the anthropogenic in pu ts from industrial wastes , degradati on of chl orin ated pesticides and use of pentachl orophenol (PCP) as a wood preservati ve8

. Signifi cant PCP contamin at ion of so il s, lakes, ri vers, and ground waters has been reported9

. Because of their tox icity to hu man and marine li fe, stringent res tricti ons have been imposed on the concentrat ion of these compounds in the wastewaters for safe di scharge.Removal of phenoli c compounds from wastewater is therefo re of utmost importance to prevent pollution of water in the receiving water course. Traditi onally, biological treatment, adsorption, sol vent extraction are widely used methods for remov ing from wastewaters 10-

14.

Phenol Removal through Adsorption

The process of adsorpti on has an edge due to its sludge-free clean operati on and complete remova l of phenols from aqueous solutions ha·vmg dilute or moderate concentrati ons. Activated carbon, m granul ar or powdered form is the most widely used adsorbentt 5

-17

. In spite of good capacity it suffers from several disadvantages . The cost of acti vated carbon is higher. Chemical as well as thermal regenerati on of spent carbon is expensive, imprac tical and produces additi onal efflu ent and results in a considerable loss of the ad sorbent 10

·12

· '8

·19

• Thi s has led many workers to search for economic, practi cal and effici ent adsorbents.

The ava il able literature on vari ous adsorbents and their adsorpti on characteri stics for di ffe rent phenols is summari zed in Tabl e 2. The adsorpti on

SINGH & SRIVASTAVA: REMOVAL OF PHENOL POLLUTANTS 209

Table !-Industri al source and concentration of phenol

Industry Concentration, (mg/L)

Cok ing plant Weak ammonia liquor 580 10.000

without dcphenoli zation Weak ammonia liquor 4-332

after dephcnolization Wash oil still was tes 30-150

Oi l refi neries Sour water 80- 185

General wastewater 10-100

A PF separator effluent 0.3-6.8

Petrochemical Benzene refinery 2 10

Tar di stillati on 300

Nitrogen works 250

Orean manufacturing 100- 150

Plastic factory 600-2000

Phenoli c res in production 1600

Fiberboard factory 150

Fiberglass manufacturing 40-400

Aircraft maintenance 200-400

capacity data reveal that non-conventional adsorbents possess remarkable capacity for the removal of phenols from aqueous solutions. The review documents various adsorbents available for removal of phenols form wastewater systems.

Many factors influence the rate of adsorption and extent to which a particular adsorbate can be adsorbed . The parameters which have been investigated for optimizing the use of non­conventional adsorbents in wastewater treatment inc lude nature of adsorbate and adsorbent, adsorbate concentration , adsorbent dose, contact time, pH of so l uti on , particle size of adsorbent, etc.

Nature of Adsorbate - The characteristics of ions, molecul es (s ize, shape, charge, etc.) present in wastewater and their concentration have profound influence on the extent of adsorption. Phenols are dissociated in aqueous medium to form anionic species at pH > 6. These anionic species adsorbs at positive ly charged surface centers on adsorbent. Streat et al. 20 have reported a c lear difference in the adsorption beh av iour of phenol and p-chlorophenol on acti vated carbon and explained this by difference in molecular size, so lubility, dissociation equi librium, and benzene ring reactivity. The sorption capacity for p-chlorophenol is greater than for phenol on each of the sample tested . Mattson eta!. 21 have suggested that phenol adsorption on carbon occurs by a donor-

acceptor complex mechanism involving carbonyl oxygen groups on the carbon surface acting as the electron donor and the aromatic ring of phenol as the acceptor.

Coughlin et at. 22 have argued that phenol adsorption on carbon involves dispersive forces between rt-electrons in the phenol and the rt-electron in the carbon . This effect is more in p-chlorophenol, since the electronegative chlorine atom attracts electrons towards the ben zene ring, thus enhancin g the activation of the molecule. Since p-chlorophenol is less soluble in water than phenol the sorption of the former is increased .

Daifullah and Girgis23 have studied the effect of six physical properties of phenols on the amou nt adsorbed. These are: molecular weight, so lubility , pKa, cross-sectional area of adsorbed phenol s, molecular volume and effective molecular diameter. They have reported that adsorption is direct functi on of these parameters. It has been seen that substituted phenol with hindered group is less adsorbed than phenol on fly ash and impregnated fly ash24 and adsorption follows the order :m- nitrophenol > o­nitrophenol > phenol > m-cresol > a -cresol .

Nature of Adsorbents- Though every solid is an adsorbent, the physicochemical nature of adsorbent can have profound effect on both, the rate and capacity for adsorption . Singh et a!. 24 have reported that impregnated fly ash has shown better efficiency of phenol removal than fly ash. The sorption of phenol, 2,4,5- trichlorophenol and tannic acid onto montmorillonite based sorbents was studied by Dente! et al.25 The sorbents used were homoionic Na­or Ca-montmorillonite, montmorillonite completely exchanged with the cationic organic surfactant dimethyl distearyl ammonium choride (or DDA-M) and DDA-M partially re-exchanged with Ca++ (Ca­DDA-M). It has been noted that sorption capacity significantly enhanced by surfactant treatment of the homoionic clay. Iron (III) hydroxide loaded marble has been reported as a potentia l adsorbent for the removal of phenols26

. The iron (ill) marble exhibited much higher adsorptivity compared to unloaded marble. The sorption capacity values of phenol and pyrocatechol on nonimpregnated and impregnated saw dust27 are 2.10, 5 .70;15 . 14, 28.01 mg/5g, respectively. Higher sorption capacity of impregnated saw dust has been explained on the bas is of iron (ill)­phenol complex formation. The adsorption capacities

210 J SC IIND RES VOL 6 1 MARCH 2002

Table 2- Adsorbents and their performance for wastewater treatment

Sl Adsorbent Selecti vity Operating conditions Adsorption /Removal References No

Conventional (A) Organic Ion

exchangers

Dowex 50 W- X8 Phenol. p- cresol Column 41

2 Amberlite- XAD Phenol. p-ni trophenol , 42-44 ch lorophenol

3 Polymeric Adsorbent Phenols 45

4 Dowex I X 4 Phenol Column 46.

5 Porous polymer based on Phenol, p- nitrophenol. Batch, cone: 60-186 mg/g 47 acry lic martix m-aminophenol I 00 mg/L

6 Macroreticular resin Phenols 48

7 Weakly bas ic anion Phenols 49 exchanger

R Anion exchange resin Phenols 50-55

9 Vinyl pyridine divinyl Phenols 56 benzene copolymer

10 Crossli nked polyvinyl Sali cyli c acid. 2,4- Batch, cone: I o·4- l o· 18-93 57 pyrrol idone dihydroxy benzoic acid, 2 M, pH 6.5 , per cent

catechol. resorcinol, equi l time: 2h p-hyd roxy benzoic acid

II Chelating Ion exchange Ch lorophenols, Column cone: I 00 28-100 58 in iron (I ll ) form nitrophenols mg/L per cent

B. Inorganic ion exchangers

12 Zinc silicate in iron (Ill ) Pyrogall ol. catechol, o- Column ,conc: I 36-1 33 28 form cresol. phenol mg/mL, equ il time: mg/g

20 min

13 Stan ni c mol ybdate Phenols Column 59

14 Zinc si licate m-,p-cresol, Impregnated paper 60 4-chlorophenol , o-nitrophenol.

15 Stannic tungstate Phenols TLC 6 1

16 Ion - exchange resins Phenols 62,63

17 Iron (Ill ) dieth anol Pyrogallol catechol , Column, cone: 24-83 64 amine resorcinol . quinol l mg/mL mg/g

18 Alu mina in Fe (Il l) fo rm Phenol, resorcinol, Column, 3-29 mg/g 65 o-chlorophenol, catechol, cone: pyrogallol I mg/mL

-Contd

SINGH & SRIVASTAVA: REMOVAL OF PHENOL POLLUTANTS 2 11

Table 2- Adsorbents and thei r performance for wastewater treatment - Co111d

Sl. Adsorbent Selecti vi ty Operating conditions Adsorption/Removal References No.

19 Hydrous ZnS Substituted phenols Batch 66

20 Nickel, cobalt and o-Nitrophenol, Batch 9.8-27. 1 mg/g 67 cadmium ferrocyanides o-ami nophenol

2 1 Iron (Ill ) hexamine Resorci nol. Column, impregnated 21-92 mg/g 68 quninol.phlorog-lucinol , paper salicyli c acid , pyrocatechol

pyrogallol

22. Iron (Ill ) morpholinc Phenol , m-aminophenol , a:- Column, cone: 24.8-1 18.9 mg/g 69 naphthol pyrocatechol. I mg/mL pyrogallol

Ac ti vated carbons

23 Acti vated carbon from Phenol, Batch , cone: 6.03 2.08 mmol /g 20 straw and used rubber p- chlorophenol mmoi/L, equil time:2h tyrcs

24 Activated carbon from 2,4- Dinitro- and Batch , cone: I 0 mg/L, 63-65 % 23 ap ri cot stone shell 2.4- di-chlorophenol s equil time: 20h

25 Activated carbon Phenols and substituted Batch 32,35.70-89 phenols

26 Burnt wood charcoal Phenol Batch, conc:25-400 1-7 mg/g 33 mg/L, pH 7, equil time lh

27 Activated carbon Phenols, Batch, equil time: 2 1 0,400 mg/g 37 Fi I trasorb- 400 p-chlorophenol 48h,

28 Activated carbon from chlorophenols 90 agricultural raw materi al and spani sh lignite

29 Activated carbon from 4-Nitrophenol 2,4,6- Batch 91. fertilizer waste slurry trinitrophenol, 4-

cholorophenol, resorcinol

30 Activated carbon from Phenol Batch, cone: I 00 28 .50 mg/g, 77.9 per 92 Jute fiber mg/L, equil time: 5h cent

31 Granular activated Phenol 93-98 carbon

32 Biological activated Phenol , 2,4- dichlorophenol Batch. cone: I 00 and 25.04 and 43.75 mg/g 99 carbon 116 mg/L, pH 7 equil

time: 25 h,

33 Surface modified carbon Phenol Batch 100 bl ack

34 Surface treated activated Phenol Batch 101 carbon

Non-conventional 35 Impregnated fl y ash Phenols, o- and m-cresols, Batch, cone: 500 9-46 24

o- and m-nitrophenol mg/L, pH 6.5, equil per cent time: 2 h

36 Montmorillonite based Phenol. 2.4.5- Batch 25 sorbents trichlorophenol , tannic acid

-Contd

212 J SCIIND RES VOL 61 MARCH 2002

Table 2- Adsorbents and their performance for was tewater treatment - Conte/

Sl. Adsorbent Select ivity Operating conditions Adsorpt ion/Removal References No_

37 Iron ( Il l) hydroxide Pyrogallo. pyrocatechol Batch 9, 10 mg/g 26 loaded marble

38 Chemicall y treated saw Pyrogallo. pyrocatechol Batch, cone: 100 28-52 mg/g 27 dust mg/L, pH 6

39 Peat. Fly ash and Phenol Batch. cone: lmg/L, 42-4 per cent 29 ben toni te pH: 4-5 . eq uil time:

16,5and 16h

40 Activa ted carbons from Phenol. o-.m -cresol, Batch. Column. 80.2- 438.4 mg/g 31 used tea leaves 4- chlorophenol . cone: 500 mg/g

4- nitro phenol 2,4 -d i chI orophen ol s. 2,4- dinitrophenol

41 Organobenton i te Phenol. m- ch lorophenol Batch, cone: I 00 80 per cent 102 mg/L. eq uiltime: 12 h

42 Organoclays p-ch Jorophenol. 103.104 tannic acid

43 Soil Sustituted phenols 105,106

44 Dol amite Phenols 107

45 Sediment fractions Phenols 108

46 Silt stone Phenols 109

47 Aquifer material and Chlorinated phenols 11 0 natural sediments

48 Na and K- Phenol , 111-cresol. Batch, pH : 5.4-6.5, 29.48- I 09.4 mg/g Ill montmorillonite 111- nitrophenol eq uil time:24h

p-bromophenol

49 Dual cation Phenol , p- nit rophenol Batch. equil time: 2h 3.4-34.4 mg/g. 112 organobentonites

50 Modified bentonites Phenols 113

51 Lake sed iments Phenols Batch, pH 7, equil 28-67 mg/g 114 time: 40 h

52 Bagasse fly ash 2.4- Trinitrophenol Batch 11 5

53 Acti va ted sludge Phenolic waste 116

54 Hcxadecyl Pentachlorophenol Batch 117 trimethylammonium montmorrilonite clay

55 Coal. fly ash and Phenol Batch 118 acti vated carbon

56 Fly ash Phenols Batch 119-126

57 Activated sludge and Phenol Batch 91 .0, 27.9 mg/g 127 fly ash

58 B iopolymers Phenol Batch 128

59 Pulped wood fiber 2.4- Dichlorophenol 129 2.4,5- trichloro-phenol

60 Polyurethane foams Phenols Batch 130

61 Fertilizer waste slurry 2.4 Dinitrophenol 13 1

Conte/

Sl GH & SRIVASTAVA: REMOVAL OF PH ENOL POLL UTA TS 213

Table 2- Adsorbents and their performance for wastewater treatment- Conte/

Sl. Adsorbent Selectivity No.

62 Low cos! carbonaceous 2,4,6 Trinitrophenol , adsorbents 4-nitrophenol.

4-chlorophenol . resorcinol

63 Activated carbon from Phenol 64 bamboo

Marine sediments 2.4-Dichlorophenol

65 Bacillus subtili s 2,4 ,6-Trichloro -phenol

of phenol , a-naphthol, a-cresol, catechol and pyrogallol on untreated zinc silicate were found to be 11.28. 30.28 , 21.63. 28.62, 42.87 mg/g, respectively. whereas the capacity va lues of zinc si li cate in Fe (III) form 28 were 35.72, 72 .09, 60.56, 96.89, 133 .67 mg/g, respectively. The higher capacity in the latter case occu rs by vi rtue of the ab ility to form compl exes of varying stabi lity wit h Fe (IJI) bound to the zi nc sili cate matri x.

Effect of Adsorbate Con centration - The increase in concentrat ion of the adsorbate results in increase in the magnitude of adsorption at a g iven temperature. Thi s parameter has been studied by several in vestigators and the resu lts are generall y expressed by a linear form of Freundlich and Langmuir adsorpti on isotherms26

'29

·30

. Figure I a and b show the linear adsorption mode ls of 4- chlorophenol (4-CP) and 4- nitrophenol (4-NP) on acti vated carbon prepared from used tea leaves31

.

Adsorbate Dose - It is important to determine the dose of adsorbent req uired to achieve a des ired level of treatment. Swamy et al?0 have studied the effect of adsorbent dose on the removal of a-cresol by bagasse and fl y ash. It is observed that the per cent remova l of a -c resol increases with increase in adsorbent dose, while removal per unit we ight of adsorben t increases with decrease in adsorbent dose. The reported optimum dose is 12 g/L for about 90 per cent removal of a -cresol (I 00 mg/L), The variation of adsorption density and fraction adsorbed against adsorbent dose for catechol removal on industrial grade granular activated carbon and laboratory grade granul ar activated carbon has been studied32

. It is observed that fraction adsorbed increases with increase in adsorbent dose. Effect of adsorbent dose studied for used tea leaves activated carbon reveals

Operating conditions Adsorption /Removal References

132

Batch 133

Batch. cone: 5-20 1.5-4 mg/g 134 mg/L

Batch 135

that 120 and 140 mg/L carbon is sufficient for I 00 per cent remova l of 4-chlorophenol and 4-nitrophenol ( I 00 mg/L), respectively31

. Effect of adsorbent dose on removal of phenol has a lso been stud ied by several other investi gators33

.

Effect of Contact Time- Adsorption of adsorbate species is faster in the initi a l stages of contact period and becomes slow near

.1. b · 24 26 29 3 t C . . . eq ut 1 num · · ·· · ontact ttme req utred to attatn equilibrium is a function of particle s ize, pH, rate of ag itat ion, temperature, etc. Pretreatment of adsorbent a lso influences the equilibrium time. The eq uilibriu m time for adsorption of phenols on impregnated fly ash24

, iron loaded marbl e26, peat29

, bagasse-fly ash30•

used tea leaves activated carbon31 and iron oxide coated sand34 are 2, 1.5, 16, 1.5 , 3 and 2 h, respectivel y.

Effect of pH- The removal of phenol from water by adsorption is highl y dependent on pH of the solution , which affects the surface charge of the adsorbent, degree of ionization , and speciati on of phenol. It is reported that per cent adsorption of phenol on activated carbon31 increases up to pH 6 and then decreases with further increase in pH. Effect of pH on batch adsorption studi es of phenol by peat, fly ash and bentonite29 indicated that phenol was better adsorbed at pH 4.0, 5.0, and 4.0, respect ively (Figure 2) . The removal of a-cresol from wastewater by adsorption onto activated carbon (laboratory grade), bagasse-fl y ash and act ivated carbon (commercial grade) was found to be hi ghly dependent on pH of the solution , which affects the surface charge of adsorbent and degree of ioni zation 30

,

Mahesh et a/. 35 have reported the favourable adsorption of phenol at low pH on activated carbon. The dec rease in adsorpti on with increase in pH has

2 14 JSCI!NDRES VOL61 MARCH2002

2.5

'" *" 2.0

--F ~

"'o

-I J'

0.0 0 3 ~

....l...x 10 2(l•g-1) Ct

2.6

10~--~----~--~--~~--~--~--~ 0.0 Ill 1.2 lA 2.0 2.~ 2J

Lt9 Ct

Figure !-Linear absorption models of 4-CP and 4-NP on activated carbon prepared from used tea leaves (a) Langmuir eq uation and (b) Freudlich equati on

been explained on the bas is of aqua-complex format ion and its subsequent acid- base dissociation at the sol id-liquid interface.

Effect of Particle Size - Adsorption is a surface phenomenon such that the extent of adsorption is proportional to specific surface area (micropores). Thus the adsorption is greater for small particle size. 36

Figure 3 shows the adsorpti on isotherms for phenol on carbon of different particle sizes37

. The difference in adsorption capaci ty with particle size is small but significant. Palanichamy et a/. 33 have reported that per cent removal of phenol decreases as the particle size of burnt wood charcoal increases . Although partic les of smalle r size provide large surface area for hi gher adsorption but are unsuitable for continuous col umn app lication.

~ 0 .:c t 0 lfl

~

60

50

40

30

20

10

0~~~~~~~----------~ 2 2.5 3 3 .. 5 4 4.5 5 5.5 6 6.5 7 7.5 8

pH

Figure 2- Effect of pH on the adsorption of phenol by peat(x),tly ash(+) , bentonite(O)

20

100

·-J'M1ide di3I!IO!<r (' ITI) 0 200 ll. 303 4 421 asos T. 1t<'C

Figure 3- Adsorpt ion isotherms for phenol on carbon

Regeneration and Disposal of Adsorbent - The common technique in regeneration is thermal volatilization m which adsorbed organics are desorbed at high temperature. Thi s process is uneconomical 38 due to loss of carbon (5-I 0 per cent) and the cost of energy in heating the carbon around 800-850°C. An a lternative techn ique is that of chemical regeneration in which chem ical reagents are

SINGH & SRIVASTAVA: REMOVAL OF PHENOL POLLUTANTS 215

applied to exhausted adsorbent. Efforts have been made to regenerate and recover the adsorbed phenols. Almost complete removal of adsorbed phenolic compounds on iron (ill) hydroxide loaded marble could be achieved with I M NaOH solution26 .This is probably due to ligand-exchange reaction ( phenol­H20 or OH' ) and thus the sodium salt of phenolic compounds were easily eluted. Sodium hydroxide has been used as a reactive chemical in the regeneration of granular activated carbon. The desorption of phenol with 4 per cent aqueous solution of sodium hydroxide has been shown to be commercially effective3

J.39.4°. The phenol reacts with caustic soda to

form sodium phenate which is readily desorbed and carried out of the carbon bed in the regenerant stream. Ethanolic-NaOH has also been reported for the desorption of phenols27

.

Since, thermal regeneration of adsorbent is likely to cause air pollution problems and chemical regeneration will lead to increased water pollution, it is not desirable to regenerate non-conventional adsorbents in view of their low cost and ease of availability provided their disposal after use is easier and safe.

Conclusions

Based on the above facts, it is observed that non-conventional adsorbents can adsorb phenol to the extent of I .5-438.4 mg/g when contacted for a period of 2-48 h in the pH range of 4 to 6. It is interesting to compare adsorption efficiency of non-conventional adsorbents with the conventional adsorbents. The results of laboratory investigations showed that non­conventional ads6rbents hold promise for effluent treatment. On the basis of higher adsorption capacity, the use of activated sludge, Na-K montmorrilonite, impregnated fly ash, chemically treated saw dust and activated carbon prepared from used tea leaves may be suggested for wastewater treatment containing phenols. Detailed economic analysis would be required in any evaluation of these adsorbents.

References

Patterson J W, cited in Wastewater treatment technology (Ann Arbor Science Ann Arbor, Mic) Ch. 18 (CRC, Press) 1988. pp 205.

2 Environmental Protection Agency; Methods 604. Phenol in federal Regis/e. October 26, 1984a, Part VIII, 40 cfr, pp58 .

3 IS 3306, cited in Tolerance limits for industrial effluents discharge into public sewers (Bureau of Indian Standards. Manak Bhavan , New Delhi, India). 1974.

4 Minimum National Standards (Water bodies) , cited in Central Bureau of Water Pollution Control (Government of India, New Delhi) 1981 .

5 Devi R C & Sastry C A. Toxicity of phenols to fish. Indian . 1 Environ Protect, 1( 1987) 271.

6 Buikema A C J, Mcginna M J, & Cairus J. Phenolics in aquatic ecosystems: A selected review of recent literature. Marine Env Res, 2 ( 1979) 87.

7 Crosby D G. cited in Environmental Chemistry or Pentachlorophenol: A Special Report on Pentachlorophenol in the Environment. In Commission on Pesticide Chemistry. (Department of Environmental Toxicology, University of California. Davis CA) 1980. pp I 052-1080.

8 Lee L, Rao P & Brusseau M, Non equilibrium sorption and transport of neutral and ionized chlorophenols, Environ Sci Tec/rnol, 25 ( 1991) 722.

9 Wall J A & Stratton G W , Comparison of methods for the extraction of pentachlorophenol from aqueous and soil system, Chemosphere, 22( 1991 ) 99.

10 Hassler J W, cited in Purification with activated carbon (Chemical Publishing Co. USA) 1974.

II Patterson J W . cited in Waste water treatment technology (Ann Arbor Science Pub, Inc. USA) 1977.

12 Perrich J R. cited in Activated Carbon Adsorption for wastewater treatment (CRS Press, Inc USA) 1981.

13 Sokal W, Uptake rate of phenol by pseudomonas putida grown in unsteady state, Biotechnol Bioeng, 32 ( 1988) I 097.

14 Haeggnlom M M, & Young L Y. Anaerobic degradation or halogenated phenols by sulphate-reducing consortia. Appl Enviro Microbial, 61 ( 1995) 1546.

15 ' Dussert B W & Van Stone G R, The biological activated carbon process for water purification, Wat Eng Manage. 141 ( 1994) 22.

16 Nakamura T , Tanada S, Kawasaki . lzawa J & Tokimoto T, Adsorption characteristics of trichloroethylene of plasma treated activated carbon. Toxicol En viron Chem. 47 ( 1995 ) 213.

17 Yang Jun & wang Yunxiu, Study on activated carbon in chromium-containing wastewater treatment by XPS. 1 Environ Sci, 6 ( 1994) 173

18 Brasquet C, Roussy J. Subrenat E & Le Cloirec P, Adsorption and selectivity of activated carbon fibers application to organics, Environ Techonol. 17( 1996) 1245.

19 Ferro- Garcia M A, Rivera- Utrilla J. Baustita-Toledo I & Moreno- Castilla C M, Chemical and thermal regeneration of activated carbon saturated with chlorophenols, 1 Chem Techno/ Biotechnol, 67 ( 1996) 183.

20 Streat M, Patrick J W & Camporo Perez M J, Sorption of phenol and p-chlorophenol from water using conventional and novel activated carbons, War Res, 29 ( 1995) 467 .

21 Mattson J S M, lnr H B. Malbin M D. Weber W J & Crittenden J C. Surface chemistry of active carbon. specific adsorption of phenols, 1 Colloid Sci, 31( 1969) 116.

22 Coughlin RW, Ezra R S & Tan R N. Influence of chemisorbed oxygen in adsoption on to carbon from aqueous solution, 1 Colloid lnterf Sci, 28 (1968) 386.

23 Dainfullah A A M & Girgis B S. Removal of some substituted phenols by activated carbon obtained from agricultural waste. Wat Res, 32 (1998) 169.

216 1 SCI IND RES VOL 61 MARCH 2002

24 Si ngh 8 K, Mishra N M & Rawat N S, Sorption characteris ti cs of phenols on fl y ash and impregnated fly ash. Indian 1 Environ Hlth. 36(1994) I.

25 Dente! S K, Bottero J Y, Khatib K, Demougeot H, Duguet J P & Ansel me C. Sorption of tannic acid . phenol and 2,4,6-trichlorophenol on organoclays, War Res, 29 ( I 995) I 273.

26 Singh D K & Mishra A. Removal of phenolic compounds from water by iron-loaded marble, Sep Sci Techno/, 28 (1993) 1923.

27 Singh D K & Mi sh ra A. Removal of phenolic compou nd from water using chemi call y treated saw dust , Indian 1 Environ Hlrh . 32( I 990) 345.

28 Si ngh D K & Darbari A. Ligand exchange chromatographi c separations of some phenoli c compounds on zinc silicate in Fe (Ill ) form, 1 Liq Chromatogr,10 ( I 987) 3235 .

29 Viraraghavan T & Alfaro F de M. Adsorpt ion of phenol from wastewater by peat. fly ash and bentonite, 1 Hazad Mat. 57( I 998) 59.

30 Swamy M M. Mall I D, Prasad 8 & Mishra I M, Sorption charac teristic of o-cresol on bagasse fly ash and acti vated carbon. Indian 1 Environ H/rh ,40( I 998) 67.

3 I Singh D K & Srivastava B, Removal of some phenols by activated carbon developed from used tea leaves, ./ Ind Poll Conr .16 (2000a) 19.

32 Mahesh S. Chitranshi U B & Deepak D. Adsorpt ion kinetics of dihydricphenol- catechol on activated carbon, Indian ./ Environ Hlth , 40 (1998) 169.

33 Palanichamy M S, Joseph B & Chandran S, Adsorption kinetics of phenol on cont rolled burnt wood charcoal system, Indian ./ Environ Protect, J 4 ( 1994) 59 1.

34 Singh D K & Srivastava B. Iron oxide coated sand as an adsorbent for chromatographi c separation and removal of phenols , ./ Liq Chromatog r. (Commu nicated).

35 Mahesh S. Rama B M, Kumari P H N & Usalaxmi K, Adsorption kinetics of di hyd ricphenol- catechol on acti vated carbon. Indian./ Environ Hit h. 40 ( 1998 ) I 69.

36 Mahesh S. Roma B M. Kumari P N H & Usalaxmi K. Adsorption kinetics of dihydric phenol- hydroquinone on ac tivated carbon. f11 dian ./ Environ Hith , 41 ( 1999) 3 17.

37 Mckay G , Bino M 1 & Altamemi A R, The adsorpt ion of various pollutants from aq ueous solution onto activated carbon. War Res. 19( 1985)491.

38 Guymon! F J cited in Activated carbon adsorption of organics from the aqueous phase. Vol 2 (A nn Arbor Science, Ann Arbor. Ml ) 1980.

39 Himmelestein K 1, Fox R D & Winter T H. In place regeneration of activated carbon, Chem Eng Pro g. 69 ( I 973) 65.

40 Fox R D, Kell er R T. cited in Puri fica tion of a waste brine by carbon adsorpt ion with emphasis on waste water reuse, Proc Twentyififth Ind Waste Conf Eng Bull. Purdue University. Indiana, (I 970) pp 322.

4 I Asthana P K & Bhatia S. Separation of phenol and p-cresol from dilute aq ueous waste streams, Indian ./ Environ Protect. 7(1994) 490.

42 Crook E H, Modondl R P & McMurty J T, Removal and recovery of phenols from industrial waste effl uents with amberlite XAD polymeric adsorbents. lnd Eng Chem Prod Res Dev, 14 (1975) I 13.

43 Devarajulu T, Rambabu K, Krishnaiah A & Viswanath D S, Adsorption of phenol, p-nitrophenol and their binary mi xtures from aqueous solutions on amberli te synthetic resin XAD-2 , /ndian ./Environ Protect, 19 (1996) 838.

44 Kennedy DC, Macroreticular polymeric adsorben ts. lnd Eng Chem Prod Res Dev. 12 (1973) 56.

45 Deshmukh S W & Pangarkar V G. Recovery of organic chemicals from effl uent by adsorption over polymeri c adsorbents. Indian Chem Eng, 26 (I 984) 35.

46 Goto M, Hayash N & Goto S, Adsopti on and desorption of phenol on anion-exchange resin and activated carbon, Envrion Sci Techno/, 20 ( I 986) 463.

47 Reddy K A, Anand P S & Dasare B D. Sorpti on of phenolic compounds on porous polymeric adsorbents based on acrylic matrix , indian 1 Environ Hlth , 31 (1989a) 197.

48 Farrier D S, Hines A L & Wang S W, Adsorpti on of phenols and benzoic acid from dilute aqueous solution on to a macroreticu lar resin , 1 Colloid lntelf Sci, 69( I 979) 233 .

49 Reddy K A. Anand P S & Dasare B D. Sorption of phenolic compounds on porous weakely basic anion exchangers on acry lic matrix . indian./ Environ H/th , 3l (l989b) 297.

50 Anderson R E & Hansen R D. Phenol sorpti on on ion­exchange resins, lnd Eng Chem. 47( I 955) 7 I.

5 I Oberoi C K. Anion exchange technique usi ng ion­exchangers for the sorption of phenol from aqueous solutions, Indian./ Environ Protect,Il ( I 99 1) 85

52 Huang T & Cho L, Adsorpt ion equ li bria of phenols on anion exchange resins in aqueous solution, Chem Eng Comm. 74 (1988) 169.

53 Goto S, Goto M & Uchi yama S. Adsorption equi li bria of phenols on anion exchange resin in aqueous solution , ./ Chem Eng .Jpn. 17 ( I 984) 204.

54 Lee K C & Ku Y. Removal of chlorophenols from aqueous solutions by ani on exchange resins. Sep Sci Tec/111ol. 31 (1996) 255 .

55 Hu ang T C & Cao LT. Batch adsorpt ion of p-ni trophenol and p-chlorophenol on ani on exchange resins, ./ Chem Eng Japan, 21 ( I 998) 498.

56 Kawabata N, Hi guchi I & Yoshida, Removal and recovery of organi c pollutants from aq uatic environment. VII. Adsoption of carboxylic acids on crossliked pol y (4-vi nyl pyridine) . ./ Bull Chem Soc Jpn , 54 ( 198 I) 3253.

57 Abdul Kadar K S, Ut hayavani 1 & Subramanian E, Sorption and removal of phenols from water using cross linked polyvinylpyrrolidon. Indian ./ En viron Protect. 18 ( I 997) 18 1

58 Petronio B M, Decaris E & Januzzi L. Some applications of li gand-exchange- ! recovery of phenoli c compounds from water, Talan ta , 28 ( I 98 I) 215.

59 Rawat 1 P. Mujtaba S Q & Thind P S, Chromatographic separation and identificati on of phenols on papers impregnated with stan nic molybdate, Z Anal Chem. 279 (I 976)368.

60 Rawat 1 P, Iqbal M & Alam M. Zinc silicate as a new adsorbent for paper chromatographi c separati on of phenol s. ./ Liq Chromatogr, 5 (1982) 967.

61 Nabi S A, Farooq ui W U & Rahman N. A semicrystaline inorganic ion-exchanger for thin layer chromatographic separation of phenolic compounds. Chromatographia , 20 (1985) 109.

SINGH & SRIVASTAVA : REMOVAL OF PHENOL POLLUTANTS 217

62 Siouffi A M. Ri ghi zza M & Guiochon G. Separation of aromati c compounds by liquid chromatograph y on diol bonded phase columns. J Chromatogr, 368 ( 1986) 189.

63 Lepri L, Desideri P G, Landini M & Turli G T , Chromatographic behaviour of phenols on thin layers of cati on and anion exchangers. J Chromatogr, 109 ( 1975)365.

64 Singh D K & Mehrotra P.Iron (Ill ) diethanolamine as a new adsorbent for chromatographic separations of phenols, J Liq Chromatogr, ll ( 1988) 1415.

65 Rawat J P. Iqbal M & Chitra, Li gand exchange separation of phenol s on alumina in Fe(II I) form , Chromatographia, 17 (1983 ) 701.

66 Liu J C & Hu ang C P . Adsorption of some substituted phenols on hydrous ZnS(s), J Coil lnteif Sci, 153 ( 1992) 167.

67 Alam T, Tarannum 1-1 & Kamaluddin . Remonal of o­nit rophenol and o-amionophenol by nickel, cobalt and cad mium ferrocyanides, J lnd Poll Con i, 15 ( 1999) 57.

68 Singh D K & Mishra A. Chromatographic separations of phenol s on a new adsorbent, J Liq Chromatogr, 15 ( 1992)369.

69 Singh D K & Srivastava B, Iron (III ) morpholine gel - A new adsorbent selective for pyrocatechol and pyrogall ol, Chem Anal, Warsaw. 45 (2000 b) 725.

70 Zagorski J S & Faust S D. Eq uilibri a of adsorption of phenols by GAC. in Chemistr)' of wastewater technology, by A J Rubin (A nn Arbor Science) 1978.

71 Martin J R, Activated carbon products selection for wastewater treatment. lnd Eng Chem Prod Rev Dev, 19 ( 1980) 435.

72 Puri B R. Bhardwa S S & Gupta U. Adsorption of phenols from aqueous solutions by carbons in relation to their speci fie surface areas, J Indian Chem Soc. 53 ( 1976) I 095.

73 Bhatia S K. Kala''' A. Joglekar H S & Joshi J B, Effective diffusivity of phenol in acti vated carbon , Chem Eng Co111111ttn , 98 ( 1990) 139.

74 Caturla F, Martin -Martinez J M. Sabio M M, Rdriguez­Reinoso F & Torregrosa R, Adsorpion of substituted phenols on act ivated carbon, J Colloid lnterf Sci, 124( 1998) 528.

75 Aytekin C. Application of polyanyl adsorption potential theory to adsorpti on of phenolic compounds from water solution onto activated carbon. Spectrosc Lett, 24 ( 1991 ) 653 .

76 Samaras P, Diamadopoulos E & Sakellaropoulos G P, Relationship between active carbon surface area and adsorption model coeffici ents for removal of phenol from water. War Qual Res J Can, 30 ( 1995) 325.

77 Takeo A & Keizo 0 . Adsorption of phenols on surface­modified carbon bl ack from its aqueous solution, J Cn/1 lnte1j Sci. 102 ( 1984)348 .

78 Gudyno T V & Belousora M Ya. Deposited Doc.VI NIT! , 1929-84. 12pp (Russ) Avail VI NIT!. 83: Gudyno T V & Belousora M Ya. l993 , Deposited Doc VI NIT!, 1929-84. 12pp (Russ) Avail VI NITI.

79 Orshansky F & Narkis N, Characteristics of organics removal by PACT simultaneous adsorption and biodegradaion. War Res.l1 ( ! 997) 391 .

80 Kilduff J E & King C J, Effect of carbon adsorbent surface properties on the uptake and solvent regeneration of phenol, lnd Eng Chem Res. 36 ( 1997) 1603.

81 Furuya E G. Chang H T, Miura Y. Yokamura H. Taj ima S. Yamashita S & Noll K E. lntraparticle mass transport mechanism in activated carbon adsorption of phenols. J Environ Eng, 122 ( 1996) 909.

82 Mostafa M A, Samara S E & Youssef A M. Removal of organic pollutants from aq ueous solutions : Part I, Adsorpti on of phenols by activated carbons. Indian J Chem. 28A ( 1989) 946.

83 Chen Y Y & Philip G P , Comparitive adsorption of phenols on activated carbon, J Environ Eng, 98 ( 1984) 976.

84 Khan A R, AI-Bahri T A & Al-Haddad A, Adsorption of phenol based organic pollutants on ac tivated carbon from multicomponant dilute aqueous solution, War R"s , 31 ( 1997) 2102.

85 Talini I & EI-Mabrouk F A, Enhanced removal of phenol and m-cresol in PAC addi tional activated sludge system. En vir Techno/. 15 ( 1994) 11 2 1.

86 Mazet M, Farkhani B & Baudu M. Influence of heat and chemical treatment of acti vated carbon on to the adsorption of organic compounds, War Res, 28 ( 1994) 1609.

87 Vidic R D , Suidan M T, Soria! G A & Bernner R C. Effect of molecular oxygen on adsorptive capacity and extraction efficien cy of granular activated carbon for three ortho substituted phenols, J Hazard Matter, 38 ( 1994) 373.

88 Julein F, Baudu M & Mazet M, Effects of the modification of the activated carbon physico-chemi cal characteristics on to the organic compounds adsorption, AQUA. 43 ( 1994) 278.

89 EI-Shahawi M S. Preconcentration and separation of some organic water polluants with polyurethane foam and activated carbon. Chromatographia, 36 ( 1993) 318.

90 Rivera Utrill a J, Utrera- Hidalgo E. Ferro- Garcia M A & Moreno- Castella C. Comparison of activated carbon prepared from agricultural raw materi als and spanish li gnites when removing ch lorophenols from aqueous solutions, Carbon, 29 ( 199 1) 613.

9 1 Srivastava S K & Tyagi R, Competative adsorption of substituted phenols by activated carbon developed from the fertilizer waste slurry, War Res, 29( 1995) 483.

92 Rayalu S S & Srivastava A. Adsorption of phenol on new adsorbent activated carbon cloth, Indian J Environ Protect. 13 (1993) 407.

93 Abuzaid N S & Nakhala G A, Di ssolved 0 2 effects on equilibrium and kinetics of phenolic adsorption by activated carbon, Environ Sci Tee/m ol, 28 (1994) 2 16.

94 Mcmanus C M A, Werthman H P & Westendorf R J, Proc Thirtyninth lnd Waste Conf, ( 1985) pp 719.

95 Kim B R, Chian E S K. Cross W H & Cheng S S. Adsorption, desorption , and bioregenaration in an anaerobic , granular activated carbon reactor for the removal of phenol, Wat Poll Coni Fed, 58 ( 1986) 35 .

96 Tanada M, Miyoshi T, Nakamura T & Tanda S. Adsorption removal of cresol by granular activated carbon for medical wastewater treatment, Bull Environ Con tamin Toxicol , 45 ( 1990)170.

97 Soria! A S, Makram T S. Redisav D V & Stephen W M, Comparati ve adsorption of phenols on GAC I: adsorption equilibrium, J Environ Eng. 119 ( 1992) I 026.

98 Wang R C, Kuo C C & Shyu C C, Adsorption of phenols on to granular acti vated carbon in liquid solid tluarized bed reactors, J Chem Tee/mol Biotechn(l /, 68 ( 1997) 187.

218 J SCIIND RES VOL 61 MARCH 2002

99 Ha S R & Yinithantharat S, Competitive removal of phenol and 2.4-dichlorophenol in biological activated carbon system, Environ Techno/, 21 , (2000) 387.

I 00 A sakawa T & Ogino K. Adsorption of phenol on surface modified carbon black from its aqueous solutions, J Coil lnterf Sci. 102 ( 1984) 348.

I 0 I Mahajan 0 P, Morino-Castilla C & Walker P L(Jr), Surface treated activated carbon for the removal of phenol from water. Sep Sci Techno/, 15 ( 1980) 1733.

I 02 Lin S H & Cheng M J, Phenol and chlorophenol removal from aqueous solutions by organobentonites, Environ Techno/. 21( 2000) 475.

I 03 Boy ad S A, Shaobai S & Mortland M M, Pentachlorophenol adsorption by organoclays, Clays Clay Miner, 36( 1988) 125 .

I 04 Den tel S K, Jamrah A J & Sparks D L. Sorption and co­sorption of I ,2.4- trichlorobenzene and tannic acid by organoclays, Wat Res. 32 ( 1998) 3689.

I 05 La gas P, Sorption of chlorophenols in the soil, Chemosphere. 17(1988) 205.

106 Scot H D, Wolf DC & Lavy T L, Apparent adsorption and microbial degradation of phenol by soil , J Environ Qual, 11 (1982) 107.

I 07 Hundsan- Baruth. B A & Seitz M G, Adsorption of selected phenols derivatives by dolomite. Environ Poll, 11 ( 1986) 15.

I 08 lsaction J P & Frink C R. Non-reversible sorption of phenolic compounds by sediment fractions : The role of sed iment organic matter, Environ Sci Techno!. 18( 1984) 43.

I 09 Laquer F C & Manahan S E, Sorption factor affecting to adsorp ti on of phenol on to slit stone, Chemosphere, 16 (1987)1431.

I I 0 Shellenberg, Leuenberger C & Schwarrenbach R P, Sorption of chlorinated phenols by natural sediment and aquifer materials. Environ Sci Techno/10 ( 1984) 652.

I I I Ray A S & Ram B. Adsorption characteristics of some phenol and phenolic effluents on sodium and TEB A­montmorillonite, /ndian J Environ Protect, 10 ( 1990) 816.

I 12 Zhu L. Chen B & Shen X, Sorption of phenol, p-nitrophenol, and aniline to dual-cation organobentonites from water, Environ Sci Techno/, 34 (2000) 468.

11 3 Zhu L, Liy and Zhang J. Sorption of organobentonite to some organic pollutants in water. Environ Sci. 31 ( 1997) 1407 ..

I 14 Madhukumar A & Anirudhan T S, Phenol exchange characteri stics of sediment samples from coconut husk retting zones. Indian J Environ Protect. 14( 1994)772.

115 Srivastava S K. Gupta V K. Johri N & Mohan D,Removal of 2.4.6-trinitrophenol using bagasse fl y ash- a sugar industry waste material. Indian J Chem Tee/mol, 2 ( 1995) 333.

116 Rozich A F. Gaudy A F & D' Adamo P D. Predicted model for treatment of phenolic waste by activated sludge, Wat Res, 17 (1983) 1453.

I 17 Stapleton M G, Sparks D L & Dente! S K. Sorption of pentachlorophenol to HDTMA-clay as a function of ionic strength and pH. Environ Sci Techno/, 28 ( 1994) 2330.

118 Mahadevaswamy M, Mall I D, Prasad B & Mishra I M. Removal of phenol by adsorption on coal, fly ash and activated carbon, Poll Res. 16 ( 1997) 170.

I 19 Sathapathy B K & Rao D V R, Phenol removal using fly ash as adsorbent, Res lnd, 29 ( 1984) 188.

120 Shei MS & Cheny S L, Proc Fortythird lnd Waste Conf. 1988.

121 Sarkar A, Singh B K & Ram B, Role of carbonaceous matter in fly ash in removing pollutants from coke oven and synthetic phenol plant effluents, Indian J Environ Protect. 10( 1990)367.

122 Banarjee K, Hong P Y, Scheremissoff P N. Shlih M S & Chanj S L, lnt Conf Physicochem Bioi Detox Hazard Waste. 1(1988) 249.

123 Haribabu E, Upadhyay Y D & Upadhyay S N, Removal of phenols from effluents by fly ash , lnt J Environ Stud. 43. ( 1993) 169.

124 Kumar S, Upadhyay S N & Upashyay Y D, Removal of phenols by adsorption on fly ash . J Chem Techno/ Biotecnol. 37 ( 1987) 28 I .

125 Deepak D, Shankaranarayana K R & Chandramauli V S. Removal of phenol from wastewater by adsorption on fly ash and soil, Asian environ, ( 1981 ) 37.

126 Khanna P & Malhotra S K, Kinetics and mechanism of phenol adsorption on fly ash, Indian J Environ Hlth . 19 (1977) 224.

127 Aksu Z & Yener J, The usage of dried activated sludge and fly ash wastes in phenol biosorption/adsorption: comparison with granular activated carbon, Em·iron Sci Hlth . 34( 1999) 1777.

128 Xing, Baoshan, McGill W B. Dudas M J. Maham Y & Hepler L, Sorption of phenol by selected biopolymers: Isotherms. energetics and polarity, Enviro11 Sci Techno!. 28 (1994)466.

129 Severston S J & Banarjee S, Sorption of ch lorophenols to wood pulp, En viron Sci Tee/mol, 30 ( 1996) 196 1.

130 EI-Shahawi M S, Farag A B & Mostafa M R. Preconcentration and separation of phenols from water by polyurethane foams, Sep Sci Techno/ , 29 ( 1994) 289.

13 1 Srivastava S K, Pant N & Pal N, Studies on the efficiency of a local fertilizer waste as a low cost adsorbent. Wat Res. 21(1987)1389.

132 Zogorski J S & Faust S D, Operational parameters for optimum removal of phenolic compounds from polluted water by column of act ivated carbon.AICHE Sym Ser .73 (1976) 54.

133 Wu F C, Tseng R L & Juang R S, Preparation of activated carbon from bamboo and their adsorption ability for dyes and phenol, J Environ Sci Hlth , 34( 1999) 1753.

134 Fytianos K. Youdrias E & Kokkali s E. Sorption-desorption behaviour of 2,4- dichlorophenol by marine sediments. Chemosphere, 40 (2000)3.

135 Daughney C J & Fein J V. Sorption of 2.4,6-trichlorophenol by bacillus subti li s. E1 vi ron Sci Techno/. 32 ( 1998) 749.