ASIAN JOURNAL OF CHEMISTRY

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1 Asian Journal of Chmistry; Vol. 29, No. 12 (17), ASIAN JOURNAL OF CHEMISTRY Isothrmal Study on Rmoval of Mthyl Rd from Aquous Solution Using Alo vra Lavs Powdr RENU SAXENA and SAPNA SHARMA * Dpartmnt of Chmistry, School of Scincs, JECRC Univrsity, JECRC Foundation, Jaipur-3 905, India *Corrsponding author: drsharmasapna@gmail.com Rcivd: 14 Jun 17; Accptd: 17 August 17; Publishd onlin: Octobr 17; AJC Th potntiality of Alo vra lavs powdr (ALP) a low cost and co-frindly adsorbnt was charactrizd and invstigatd for th rmoval of mthyl rd dy from an aquous solution using a grn approach by th procss of adsorption. Th adsorption bhaviour of th biosorbnt was invstigatd by prforming both kintic and quilibrium isothrmal studis in batch conditions at 34 ºC. Adsorption xprimnts wr prformd by changing diffrnt xprimntal paramtrs i.., contact tim, initial dy concntration, adsorbnt dos, particl siz and ph of th solution. Th adsorption studis wr bst fittd with Langmuir isothrm and it givs monolayr adsorption capacity of mg/g at ph 4.2 at 34 ºC. Th corrlation cofficint valus indicat a modrat fit for monolayr Langmuir modl (R 2 = 0.99). Th xprimntal and calculatd valus for amount of adsorbd dy pr unit mass of sorbnt (q ) for psudo-scond-ordr kintic modl wr in good agrmnt as compard to that by psudo first ordr kintics. Th structural charactrization of Alo vra lavs powdr was prformd by SEM, FTIR and by GC-MS. Kywords: Alo vra, Mthyl rd dy, Adsorption study, Corrlation cofficint, Isothrm modls, Kintics. INTRODUCTION With incrasing of gnration of tchnologis, watr pollution is continuing a grat concrn problm. With day by day collctiv amount of dys in th watr rcivd from fast activitis of txtil industris and as a rsult humans and animals ar facing various problms along with aquatic nvironmnt [1]. As dys ar broadly usd in industris such as txtil, papr, plastic and lathr for th coloration of products, th fflunts manating from ths industris oftn contain high concntrations of dy wasts [2]. Synthtic dys can caus considrabl nvironmntal pollution and ar srious halth hazards [3]. Various tchniqus hav bn mployd for th tratmnt of dy baring industrial fflunts. It includs prcipitation, adsorption, ion xchang [4], ion xchang mmbran procss [5], and lctro chmical tchnologis [6]. All of ths mthods hav its own drawback and limitations [7].Thrfor, th sarch for fficint, co-frindly and cost ffctiv rmdis for wast watr tratmnt hav bn initiatd [8]. Now a days, rsarch attntion has bn focusd on nvironmnt frindly mthods for th tratmnt of fflunts [9]. Bioadsorption is on of th mthods that do not rquir nrgy and th procsss can b carrid out in situ at th contaminatd sit and also thy ar cost ffctiv [10]. In ths adsorption mthods, plant matrials wr usd as biosorbnts for th rmoval of toxic dys and mtals through adsorption [11]. Plant matrials ar mainly comprisd of cllulos matrials that can adsorb dys in aquous solution [12]. Numrous wast biomass sourcs ar availabl in natur in which adsorption proprtis hav bn rportd such as bagass pith [13], sawdust [14], ric husk [15], ucalyptus bark [16], fly ash [17], hazlnut shll [18], tc. Scintific invstigations on Alo vra hav gaind mor attntion ovr th last svral dcads du to its svral mdicinal proprtis [19]. Alo vra has a long history as a mdicinal plant with divrs thraputic applications. Th plant Alo vra, blongs to th family Liliaca and is a cactus-lik prnnial plant []. Th gnus Alo contains ovr 0 diffrnt spcis with Alo barbadnsis Millr [21]. Th Alo vra plant has bn known and usd for cnturis for its halth, bauty, mdicinal and skin car proprtis [22]. In th prsnt study, Alo vra lavs powdr was studid as a nw sorbnt for th rmoval of azo dy, mthyl rd from aquous solutions by adsorption undr various conditions lik ph, adsorbnt dos, agitation tim and particl siz. EXPERIMENTAL Th instrumnts usd in this work includ spctrophotomtr (Digital UV Spctrophotomtr, Modl UV, Chmito mak), Digital ph mtr (Elctronic India, EI Modl 112), Standard tst siv (MSECO Maharani Scintific and Engin-

2 2744 Saxna t al. Asian J. Chm. ring Coopration, Dlhi) and orbital shakr (Rmi Instrumnt Ltd., IHB, 597). Adsorbat: An azo dy mthyl rd, having ph 4.2, m.f. C 15H 15N 3O 2, m.w g/mol, m.p. 180 C was purchasd from Mrck Ltd., India. Th mthyl rd show maximum absorption at wavlngth 525 nm. Adsorbnt: Matur Alo vra lavs collctd from a local park of Jaipur city, India. Alo vra lavs wr washd with distilld watr to clan it thoroughly. Thy wr thn cut into small pics and allowd to dry at room tmpratur in a shadow for 2-3 wks. Lavs wr thn kpt in an air ovn at to 70 ºC for 3 h till th lavs bcam brittl. Th drid lavs wr thn grindd by mchanical grindr to convrt into fin powdr. Th powdr was sivd to diffrnt particl siz of 0, 0 and 1 µ for th dcolorization xprimnts. Finally, th product was stord in vacuum dsiccators until rquird. Th powdr so obtaind was namd as Alo vra lavs powdr (ALP). No othr chmical or physical tratmnts wr usd prior to adsorption xprimnt. Biosorption studis: Th batch sorption xprimnts wr carrid out in 2 ml Erlnmyr flask whr 0.10 g of adsorbnt (Alo vra lavs powdr) and ml mthyl rd dy solution (100-0 ppm) at ph 4.2 wr addd at 34 ºC. Th ph of solution was maintaind by adding 1N NaOH and 1 N HCl solutions. Th Erlnmyr flask was cappd and agitatd in an isothrmal shakr at 100 rpm at 34 ºC for 4 h to achiv quilibrium. Th concntration of dy in solution aftr quilibrium adsorption was dtrmind by UV-visibl spctrophotomtr at 525 nm. Th amount of adsorption at quilibrium (q, mg/ g), was calculatd as follows: (Co C )V q = (1) W whr C o and C (mg/l) ar th liquid-phas concntration of dy at initial and quilibrium stat, rspctivly. V is th volum of th solution (L) and W is th mass of dry adsorbnt (g). Kintic studis of adsorption wr also carrid out at various concntrations of mthyl rd and th xtnt of adsorption was invstigatd as a function of tim. Th amount of adsorption (q t, mg/g) at tim t, was calculatd as: (Co C t )V qt = (2) W RESULTS AND DISCUSSION SEM: Fig. 1(a-b) shows th scanning lctron microscopy micrographs of Alo vra lavs powdr sampl bfor adsorption of mthyl rd and Alo vra lavs powdr loadd with mthyl rd. Th Alo vra lavs powdr xhibitd unvn and cav lik rough surfac morphology. Th surfac of dy loadd adsorbnt indicats that som of th surfac of Alo vra lavs powdr was covrd with dy molculs. Th unvn surfac of mthyl rd loadd Alo vra lavs powdr show that various functional groups prsnt on adsorbat and adsorbnt play important rol in th procss of adsorption. Th GC-MS spctra (Fig. 2) for Alo vra lavs powdr show major pak on rlativ abundanc of 6-mthyl-smthyln-2-hptanon and two othr major compounds ar 2,2,5-trimthyl-3,4-hxandion and 1-trt-butyl-3,3-bis (trifluoromthyl)diaziridin with rlativ abundanc and Rlativ abundanc Fig. 1. SEM micrographs of (a) frsh ALP and (b) MR adsorbd ALP Tim (min) Fig. 2. GC-MS of ALP 22.25, rspctivly. Othr paks ar du to othr minor compounds prsnt in Alo vra lavs powdr. Charactrization of ALP through FTIR: Fourir transform infrard (FTIR 00, Prkin, Elmr) analysis wr applid on mthyl rd dy adsorbd ALP to dtrmin th surfac functional groups. Aftr dy adsorption, it has bn clard that som paks has bn liminatd and som has bn rducd in its pak lngth as many sorption sits occupid du to adsorption. Th FTIR spctrum of ALP is shown in Fig. 3a. Spctra show its following paks at cm -1 (N-H strtching in amins and amids ), 2926 cm -1 (C-H strtching in alkans), 1716 cm -1 (C=O

3 Vol. 29, No. 12 (17) Isothrmal Study on Rmoval of Mthyl Rd from Aquous Solution Using Alo vra Lavs Powdr 2745 Transmittanc (%) Wavlngth (cm ) Fig. 3(a). FTIR of frsh ALP strtching in aldhyds and saturatd aliphatic group), 18 cm -1 (N-H bnding in amins),1036 cm -1 (N-O strtching in nitro compounds), 700 cm -1 (shows alkyns groups). It was found that Alo vra lavs powdr show larg fluctuations in polysaccharid composition. It has bn found that th composition of alo parnchyma tissu or pulp ar protins, lipids, amino acids, vitamins, nzyms, inorganic compounds and small organic compounds in addition to th diffrnt carbohydrats [23].Th mannosyl rsidus prsnt in a rsrv polysaccharid with a significant sasonal influnc [24]. Fig. 3b shows FTIR spctra for mthyl rd adsorbd ALP. Th spctra show th paks at cm -1 (du to strtching in O-H group, alcohol, phnol group), cm -1 (C-H strtching in alkn group) and 2853 cm -1 (C-H strtch, alkan), 17 cm -1 (C=O strtching in str and saturatd aliphatic group), 1613 cm -1 (N-H bnding in amins), 1439 cm -1 (C-C strtching in ring in aromatics group), 1052 cm -1 (C-O strtching in alcohol and carboxylic acids). It is clar that th biosorbnt displays a numbr of sorption paks, showing th complx natur of adsorbnt. FTIR spctra show that th hydroxyl and carbonyl groups ar th main functional groups which ar prsnt on th surfac of th biosorbnt and ar involvd in th procss of biosorption. Comparing th spctra, significant changs wr obsrvd which shows that ths groups play significant rol in adsorption. C ppm 0 ppm 0 ppm 0 ppm 0 ppm Agitation tim (h) Fig. 4. Effct of initial dy concntration on rmoval of MR by ALP (conditions: sorbnt dosag (W), 0.10 g; initial ph, 4.2; tmpratur, 34 C; particl siz, 0 µ; stirring rat, 110 rpm; V, ml) dcrass with th progrss of adsorption until th quilibrium is rachd.th amount of mthyl rd dy adsorbd at quilibrium (q ) incrasd from to.5 mg/g, as th concntration of dy was incrasd from 100 to 0 ppm. Th initial dy concntration gnrats a driving forc to ovrcom all mass transfr rsistancs of th dy btwn th aquous and solid phas. Hnc, a highr initial concntration of dy will nhanc th adsorption procss. Th mthyl rd rmoval dcrasd from 53.7 to 27 % as mthyl rd concntration was incrasd from 100 to 0 ppm.th quilibrium conditions wr rachd within 3 h. Rsults shows that th prcntag of dy rmoval dcrass on incrasing initial concntration of mthyl rd dy. Fig. 5 shows th plot btwn initial dy concntration and th prcntag of th dys rmovd. Transmittanc (%) Wavlngth (cm ) Fig. 3(b). FTIR of ALP loadd with MR dy Effct of initial concntration on dy adsorption: Th ffct of initial mthyl rd concntration (100-0 ppm) on th intak rat by ALP adsorption at adsorbnt dosag of 0.10 g and mixing spd of 110 rpm is shown in Fig. 4. It can b sn that th adsorption at diffrnt concntration is gradually Rmoval (%) Dy concntration (ppm) Fig. 5. Effct of initial dy concntration on prcntag rmoval of MR by ALP (conditions: sorbnt dosag (W), 0.10 g; initial ph, 4.2; tmpratur, 34 C; particl siz, 0 µ; stirring rat, 110 rpm; V, ml; dy concntration,100-0 ppm; agitation tim, 1 h) Effct of ph on adsorption: Th ffct of ph on adsorption was studid using 100 ppm dy concntration, dosag 0.10 g, ph 2-10 at 34 ºC. Dy rmoval incrasd from 22.3 to 41 % as ph incrass 2 to 4, thn it dcrass from 41 to 34.2 % as

4 2746 Saxna t al. Asian J. Chm. ph furthr incrass to 10 (Fig. 6).Th q was found to incras with incrasing ph from 6.69 to12.3 mg/g and dcrass upto mg/g. In acidic mdium, th positiv charg incrass on th adsorbnt surfac causing an incras in th lctrostatic attraction btwn anionic dy molculs and th surfac of adsorbnts so thr is an incrasd rat of adsorption of th dy. On th othr hand as concntration of hydroxyl ions (OH ) on th adsorbnts incrass, it compt ffctivly with th dy molculs lading to dcrasd prcnt adsorption onto th surfac of adsorbnt. Rmoval (%) Rmoval (%) Fig Adsorption dos (g) Effct of biosorbnt dosag (g) on prcntag rmoval of MR by ALP (conditions: initial ph, 4.2; tmpratur, 34 C; particl siz, 0 µ; stirring rat, 110 rpm; V, ml; Dy concntration, 100 ppm, tim, 1 h) Fig ph Effct of solution ph on prcntag rmoval of MR by ALP (conditions: sorbnt dosag (W), 0.10 g; initial ph, 4.2; tmpratur, 34 C; particl siz, 0 µ; stirring rat, 110 rpm; V, ml; dy concntration, 100 ppm; agitation tim, 1h) Rmoval (%) Effct of biosorbnt dos on adsorption: Th xprimnts wr conductd with constant dy concntration (100 ppm) and sampls with diffrnt biosorbnt dosags ranging from 0.10 to 0.25 g undr constant tmpratur at 34 ºC and ph 4.2 for 1 h. It was obsrvd that prcntag of dy adsorption incrasd with incras of adsorbnt dos. Th rmoval of dy incrass from 21 to 57 % with th incras of sorbnt dos from 0.05 to 0.25g. This is mostly du to an incras in th adsorption surfac ara and th availability of mor activ availabl sits. In Fig. 7, th slop is positiv, which indicats that adsorption incrass with an incras in adsorption dos. It is clar that a crtain amount of dy is adsorbd by a fixd mass of th adsorbnt. Effct of particl siz on biosorption: Prcntag rmoval of dy incrass on dcrasing particl siz. It is du to th rason that mor fin powdr incrass th surfac ara for adsorption. On rducing particl siz from 0 to 1 µ, prcntag rmoval incrass from 41 to 59.7 % (Fig. 8). Effct of agitation tim on adsorption: Batch quilibrium studis wr carrid out by adding fixd amount of sorbnt 0.10 g to 100 ppm dy solution at 4.2 ph at 34 ºC (Fig. 9). Aliquots wr agitatd in shakr at 110 rpm at diffrnt constant tim (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 h) and concntrations wr analyzd. Du to highr contact tim, prcntag rmoval of dy incrass. On incrasing agitation tim from 0.5 to 3 h, prcntag rmoval of dy incrass from 32 to 53.7 % Particl siz (µ) Fig. 8. Effct of particl siz on prcntag rmoval of MR by ALP (conditions: sorbnt dosag (W), 0.10 g; initial ph, 4.2; tmpratur, 34 C; stirring rat, 110 rpm; V, ml; Dy concntration, 100 ppm; Agitation tim, 1 h) Rmoval (%) Agitation tim (h) Fig. 9. Effct of agitation tim on prcntag rmoval of MR by ALP (conditions: sorbnt dosag (W), 0.10 g; initial ph, 4.2; tmpratur, 34 C; stirring rat, 110 rpm; V, ml; Dy concntration, 100 ppm)

5 Vol. 29, No. 12 (17) Isothrmal Study on Rmoval of Mthyl Rd from Aquous Solution Using Alo vra Lavs Powdr 2747 Adsorption isothrms: Th adsorbat concntration in bulk and adsorbd amount at th intrfac can b rlatd by mans of adsorption isothrms. Th isothrm rsults wr analyzd using Langmuir and Frundlich isothrms. Th Langmuir adsorption modl [25] is basd on th assumption that maximum adsorption corrsponds to a saturatd monolayr of solut molculs on th adsorbnt surfac, with no latr intraction btwn th sorbd molculs.th xprssion of th Langmuir modl is givn as follows: QobC q = (1 + bc ) (3) whr q (mg/g) and C (mg/l) ar th amount of adsorbd dy pr unit mass of sorbnt and unadsorbd dy concntration in solution at quilibrium, rspctivly. Q o is th maximum amount of th dy pr unit mass of sorbnt to form a complt monolayr on th surfac bound at high C, and b is a constant rlatd to th affinity of binding sits (L/mg).Th Langmuir quation can b dscribd by th linarizd forms shown in qn. 4: C 1+ C q Q = (4) A graph btwn spcific adsorption C /q against quilibrium concntration C givs linar plot (Fig. 10), which shows that th adsorption obys th Langmuir modl. Th Langmuir constants Q o and b wr dtrmind from th slop and intrcpt of th plot. Th ssntial charactristic of Langmuir isothrm can b xprssd in trm of a dimnsionlss constant sparation factor R L which is givn as follows: 1 RL = (1 + bc o) (5) whr C o is highst initial concntration of adsorbat (mg/l or ppm) and b (L/mg) is Langmuir constant. Th valu of R L indicats th shap of th isothrms to b ithr unfavourabl (R L > 1), linar (R L = 1), favorabl (0 < R L < 1), or irrvrsibl (R L = 0). In prsnt study, valu of R L coms out to b for adsorption of mthyl rd dy onto ALP. Furthr, th invstigation was corrlatd with valu of corrlation cofficint. Th study shows valu of corrlation cofficint (R 2 ) as Th Frundlich isothrm [26] dscribs htrognous systm by qn. 6: C /q o Fig. 10. Langmuir Modl curv for MR sorption onto ALP at 34 C C q = K FC 1/n (6) whr K F and n ar Frundlich constant. K F [mg/g (L/mg) 1/n ] is th adsorption capacity of th sorbnt and n givs an indication of favourabl adsorption procss. Th magnitud of xponnt, 1/n, givs an indication of favorability of adsorption. Valu of n > 1 rprsnt favourabl adsorption condition [27]. To dtrmin th constants K F and n, th linar form of th quation usd to produc a graph of ln q against ln C (Fig. 11). Valu of K F and n ar calculatd from th intrcpt and slop of th plot using qn. 7: 1 ln q = ln K F + ln C n (7) In q In C Fig. 11. Frundlich modl curv for MR sorption onto ALP at 34 C Th valu of R 2 according to Frundlich isothrm coms out to b Th rsults for various isothrms ar shown in Tabl-1. TABLE-1 LANGMUIR AND FREUNDLICH MODEL CONSTANTS AND CORRELATION COEFFICIENT FOR BIOSORPTION OF MR ONTO ALP Langmuir isothrm Isothrm paramtrs Frundlich isothrm Isothrm paramtrs Q o (mg/g) K F 3.17 b (L/mg) n 2.26 R R R L As shown in Tabl-1, th Langmuir isothrm is quit fit wll with th xprimntal data as corrlation cofficint R 2 is But in cas of Frundlich isothrm, th corrlation cofficint R 2 is lss than 0.99, which show lss agrmnt with xprimntal data. Th monolayr adsorption capacity according to Langmuir modl was mg/g. Th Langmuir isothrm fit wll bcaus of homognous distribution of activ sits onto ALP surfac. Adsorption kintics: Adsorption kintics was studid with psudo-first-ordr modl which was xplaind by Lagrgrn [28] as in qn. 8: k1t log (q q t ) = log q (8) 2.3

6 2748 Saxna t al. Asian J. Chm. A linar plot of log (q q t) against tim allows on to obtain th rat constant (Fig. 12). If th plot was found to b linar with good corrlation cofficint, thn it indicats that Lagrgrn's quation is appropriat to mthyl rd dy sorption on ALP. Th rsults of Lagrgrn's first ordr rat constant (k 1) and q dtrmind from th modl ar prsntd in Tabl-2 along with th corrsponding corrlation cofficints. It was found that th calculatd q valus do not agr with th xprimntal q valus which furthr suggst that th adsorption of mthyl rd dy do not follow first-ordr kintics. t/q t ppm 0 ppm 0 ppm 0 ppm 0 ppm log (q q t) ppm 0 ppm 0 ppm 0 ppm 0 ppm Agitation tim (h) Fig. 12. Psudo-first-ordr adsorption kintics of MR onto ALP Th psudo scond-ordr kintics [29] can b xprssd in a linar form as follows: t 1 1 = + q k q q t (9) 2 t 2 whr th quilibrium adsorption capacity (q ), and th scond ordr constants k 2 (g/mgh) can b dtrmind xprimntally from th slop and intrcpt of plot t/q t vrsus t (Fig.13). Th k 2 and q dtrmind from th scond ordr modl ar prsntd in Tabl-2 along with th corrsponding corrlation cofficints. Thr is an agrmnt btwn q xprimntal and q calculatd Agitation tim (h) Fig. 13. Psudo scond-ordr adsorption kintics of mthyl rd dy onto ALP valus for th psudo scond-ordr modl. Th valu of corrlation cofficint R 2 = 0.99 which furthr indicats that psudo scond-ordr modl bttr rprsntd th adsorption kintics and kintics rat dpnds on both adsorbnt and adsorbat concntration. Similarly, th kintic study of mthyl rd dy on activatd carbon prpard from Annona squmosa sd was analyzd basd on psudo first-ordr and psudo scond-ordr. Th data indicats that th adsorption kintics follow th psudo scondordr []. Adsorption capacity of ALP has bn compard with various othr biosorbnts. On comparing th adsorption capacity of ALP with othr biosorbnts (Tabl-3), it can b concludd that ALP could b usd as bttr biosorbnt. Conclusion In th prsnt invstigation, th adsorption ability of Alo vra lavs powdr (ALP) to rmov mthyl rd dy from aquous solution was invstigatd. Variation in various paramtrs viz., initial dy concntration, biosorbnt concntration, ph of solution was conductd during xprimntal work. Dcolourization TABLE-2 COMPARISON OF THE PSEUDO-FIRST-ORDER, PSEUDO-SECOND-ORDER ADSORPTION RATE CONSTANT AND CALCULATED AND EXPERIMENTAL q VALUES OBTAINED AT DIFFERENT INITIAL MR CONCENTRATION Conc. initial Psudo-first ordr kintic modl Psudo-scond-ordr kintic modl (mg/l) q xp (mg/g) K 1 (1/h) q cal (mg/g) R 2 K 2 (g/mg h) q cal (mg/g) R TABLE-3 COMPARISON FOR ADSORPTION CAPACITY OF DIFFERENT BIOSORBENTS FOR REMOVAL OF MR DYE Biosorbnt usd Adsorption capacity (mg/g) Rfrnc Algrian bntonit-typ clay from Mostaganm rgion (MBC) 2.0 [31] Nplhlium lappacum sd [32] Modifid banana trunk fibrs (BTF) 8.74 [33] Banana Psudostm Fibrs [34] Annona squmosa sd.486 [] Alo vra lavs powdr (ALP) Prsnt study

7 Vol. 29, No. 12 (17) Isothrmal Study on Rmoval of Mthyl Rd from Aquous Solution Using Alo vra Lavs Powdr 2749 xprimnts wr also prformd with rspct to agitation tim and particl siz. Adsorption modling of xprimntal data was conductd through Langmuir and Frndulich isothrm modl. It is found that Langmuir adsorption isothrm fittd wll with monolayr adsorption capacity as mg/g at ph 4.2 at 34 ºC and show bttr corrlation cofficint as as compard to that obtaind through Frndulich isothrm. This is bcaus of ffctiv intr-actions of various activ groups on Alo vra lavs powdr with mthyl rd dy. Rsults for kintic study ar in wll agrmnt for psudo scond-ordr kintic quation (R 2 > 0.99) conclud that Alo vra lavs powdr could b usd as on of th low cost biosorbnt for rmoval of mthyl rd dy from aquous solutions. ACKNOWLEDGEMENTS On of th authors, (RS) acknowldg th rsarch grant provid by Vic-Chairman of JECRC Univrsity, for hr rsarch work. Th authors acknowldg to Prsidnt, JECRC Univrsity, for providing laboratory facilitis. Thanks ar also du to SEED, Dpartmnt of Scinc and Tchnology, Nw Dlhi for providing WTP (Womn Tchnology Park) to JECRC and financial support. REFERENCES 1. N. Ahalya and T.V. Ramachandra, Rstoration of Wtlands-Fasibility Aspcts of Biological Rstoration, Th National Confrnc, Coimbator, India (02). 2. G.S. Gupta, S.P. Shukla, G. Prasad and V.N. Singh, Environ. Tchnol., 13, 925 (1992); 3. E. Forgacs, T. Csrháti and G. Oros, Environ. Int.,, 953 (04); 4. P.K. Sinha, R.V. Amalraj and V. Krishnasamy, Radiochim. Acta, 65, 125 (1994); 5. A.F. Nchav, V. Projav and V.P. Kapranchik, Radioactiv Wast Managmnt and Environmntal Rmdiation, Int. Confrnc, Amrican Socity of Mchanical Enginrs, Nw York, p (1995). 6. A. Szygula, E. Guibal, M.A. Palacín, M. Ruiz and A.M. Sastr, J. Environ. Manag., 90, 2979 (09); 7. S.M. Ghorishi and R. Haghighi, Chm. Eng. J., 95, 163 (03); 8. Z. Aksu, Procss Biochm.,, 997 (05); 9. A. Gurss, C. Dogar, M. Yalcin, M. Acikyildiz, R. Bayrak and S. Karaca, J. Hazard. Matr., 131, 217 (06); I. Michalak, K. Chojnacka and A. Witk-Krowiak, Appl. Biochm. Biotchnol., 170, 1389 (13); S.J.T. Pollard, G.D. Fowlr, C.J. Sollars and R. Prry, Sci. Total Environ., 116, 31 (1992); A.J. Varma, S.V. Dshpand and J.F. Knndy, Carbohydr. Polym., 55, 77 (04); Y.S. Ho and G. McKay, Procss Biochm., 38, 1047 (03); V.K. Garg, M. Amita, R. Kumar and R. Gupta, Dys Pigmnts, 63, 243 (04); G. McKay, J.F. Portr and G.R. Prasad, Watr Air Soil Pollut., 114, 423 (1999); L.C. Morais, O.M. Fritas, E.P. Gonçalvs, L.T. Vasconclos and C.G. Gonzálz Bça, Watr Rs., 33, 979 (1999); P. Janos, H. Buchtova and M. Ryznarova, Watr Rs., 37, 4938 (03); S. Aygün, S. Ynisoy-Karakas and I. Duman, Micropor. Msopor. Matr., 66, 189 (03); K. Eshun and Q. H, Crit. Rv. Food Sci. Nutr., 44, 91 (04); A. Surjush, R. Vasani and D.G. Sapl, Indian J. Drmatol., 53, 163 (08); A. Bozzi, C. Prrin, S. Austin and F.A. Vra, Food Chm., 103, 22 (07); M.Z. Haqu, M.B. Islam, M.A. Jalil and M.Z. Shafiqu, IOSR J. Appl. Chm., 7, 36 (14); G.R. Wallr, S. Mangiafico and C.R. Ritchy, Proc. Okla. Acad. Sci., 58, 69 (1978). 24. A. Fmnia, P. García-Pascual, S. Simal and C. Rosslló, Carbohydr. Polym., 51, 397 (03); J. Easto and J.S. Dalton, Adv. J. Colloid Intrfac Sci., 85, 103 (00); H. Frundlich, Z. Phys. Chm., 57U, 385 (1907); V.J.P. Poots, G. McKay and J.J. Haly, J. Watr Pollut. Contr.,, 926 (1978). 28. S. Lagrgrn, K. Svn. Vtnskapsakad. Handl., 24, 1 (1898). 29. Y.S. Ho and G. McKay, Chm. Eng. J., 70, 115 (1998); T. Santhi, S. Manonmani and T. Smitha, Chm. Eng. Rs. Bull., 14, 11 (10); K. Boudouara, M. Ghlamallah and H.N. Khmlich, Adsorption of Mthyl Rd from Aquous Solutions by Algrian Bntonit Clay, 2nd Intrnational Congrss on Enrgy Efficincy and Enrgy Rlatd Matrials (ENEFM14), Springr, Springr Procdings in Enrgy, p. 3 (14). 32. R. Zin, A.W. Astuti, D. Wahyuni and F. Furqani, Rs. J. Pharm. Biol. Chm. Sci., 6, 86 (15). 33. M. Rosmal, H.M. Haris and K. Sathasivam, Arch. Appl. Sci. Rs., 2, 9 (10). 34. M. Rosmal, H.M. Haris and K. Sathasivam, Am. J. Appl. Sci., 6, 1690 (09);