The investigation of experimental condition and Kinetic study of Methylene Blue adsorption onto Neem (Azadirachta indica) leaf powd

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1 Intrnational Journal of Scintific and Rsarch Publications, Volum 4, Issu 10, Octobr Th invstigation of xprimntal condition and Kintic study of Mthyln Blu adsorption onto Nm (Azadirachta indica) laf powd Kornwipha Sangbutr, Nittaya Wangphon and Ratchankorn Wanchanthuk Th Cntr of Excllnc for Innovation in Chmistry and dpartmnt of Chmistry, Faculty of Scinc, Mahasarakham Univrsity, Kantarawichai District, Mahasarakham 44150, Thailand Abstract- Th mthyln blu (MB) absorption onto nm laf powdr was invstigatd in trm of both adsorption fficincy and kintic study. Th ffcts of opration paramtrs i.., MB concntration, tim of adsorption, adsorbnt dosag, ph of solution and tmpratur wr invstigatd. Th rsults showd that all paramtr could affct th adsorption fficincy. Th adsorption isothrm and kintics ovr various ph and tmpratur wr also studid. It was found that th adsorption capacity was incrasd with ph and tmpratur incrasd; suggstd th xothrmic procss. Th xprimntal data showd that th MB adsorption was fittd with Langmuir isothrm and th kintic modl was th psudo-scond ordr. Indx Trms- Mthyln blu, Adsorption, kintic study, Nm laf powdr T I. INTRODUCTION h nvironmntal concrns including th sustainabl nrgy, r-usd matrials as wll as th nvironmntal frindly opration ar th oftn mntiond topics in vry organization. Nowadays, th industrial tchnology has bn rapidly dvlopd to support th fast incrasing of th population dmands. Howvr, ths industrial could rlas th toxic fflunt into th rivr and caus th nvironmntal problm. Th asy paramtr to classify th wast watr is th color, thrfor th contaminatd dy in wast watr nd to b rmovd bfor rlasd to natural stram. Th dy rmoval procss which is th low cost of opration and occurrd through th grn raction undr th usag of th natural wast is th intrstd mthod. This is ladd to th d-colorizing of wast watr by using th agricultur wast through th adsorption tchniqu. Th advantags of this tchniqu among th othrs ar th as of opration, various sourc of adsorbnt, conomy favourabl, nvironmntal frindly and sparatd asily aftr procss. Thr ar many agricultur wasts which proposd as adsorbnts such as carbonizd jackfruit pl [1], appl pomac, what straw [2], orang pl [3], watr hyacinth roots [4], watr hyacinth [5], raw and activatd dat pits [6], prlit [7], ric husk [8], panut hull [9], palm fruit bunch [10], sawdust [11], coir pith [12] and nm laf powdr [13]. Nm tr or Azadirachta indica of family Mliaca is th dciduous tr spcis and common find in Thailand. Its frsh or grn lavs, bark, sd, flowr and othr parts hav bn usd traditionally in mdicinal, grmicidal and insct psticid [13]. During th autumn sason, th matur lavs ar dfoliatd and bcom th hug volum of wast during Dcmbr to Fbruary. Th falln lavs normally lft without any usag. Th possibl application of ths lavs to incras th valu is using as th adsorbnt. Thrfor, th falln lavs wr collctd to prpar as th adsorbnt for MB rmoval in th prsnt study. Th MB was slctd as th poisond organic dy which could b prsntd in wast watr. Th xprimntal condition such as th initial concntration of MB, th adsorbnt loading, ph and tmpratur was invstigatd. Th amount of MB was followd by using th simpl apparatus which was th spctromtr. Thn, th adsorption isothrm (Langmuir and Frunlich isothrm) and th kintic modl wr finally invstigatd. II. EXPERIMENTAL 2.1 Nm laf powdr prparation Th falln laf of nm was collctd and washd with distilld watr for svral tims to rmov th dust and dirt. Th clan nm laf was thn lft at room tmpratur for 6 hours to rmov th xcss watr and thn drid undr th ovn at 100 ºC for 24 hours. Th sampl was crushd in mortar and scrnd to sparat th particl lss than 250 m using th siv in ordr to achiv th powdr. Th rsultd powdr was boild in watr for 2 hours to rmov th rsidual pigmnt and digstd som of th laf fibr. Thn th mixtur was filtrd and drid at 100 ºC for 24 hours; rsultd th nm laf powdr for furthr study. 2.2 Adsorption study Th stock solution of MB ( M) was first prpard and thn dilutd ( M). Th batch xprimnts wr carrid out to study th ffct of MB concntration, nm laf powdr loading, ph and tmpratur. Th invstigatd paramtr was varying and kpt othr paramtrs constant. In ordr to study th ffct of initial MB concntration, th scond stock solution was dilutd into M and adjustd ph to 5 by using ithr HCl or NaOH. Th solution of MB was stirrd and hatd to dsird tmpratur (60 ºC), thn th nm laf powdr was addd to th mixtur (1.2 g/l). Th mixtur was kpt stirring and hatd for 70 min, thn th mixtur was subjctd to cntrifug and th suprnatant was masurd th concntration of rsidual MB by Spctrophotomtr at 665 nm. 2.3 Calculation

2 Intrnational Journal of Scintific and Rsarch Publications, Volum 4, Issu 10, Octobr Th prcntag of dy adsorbd (%MB rmoval) and th amount of dy adsorbd on nm laf powdr (q t ) wr calculatd by quation (1) and (2), rspctivly C in C C out 100 % MB rmoval in (1) whr C in and C out dnot to th initial and final concntration of MB (mol/l), rspctivly. Th MB rmoval pr unit wight of adsorbnt at tim t, q t (mg/g) wr obtaind from quation (2) Cin Cout qt V M (2) V is th volum of MB solution in adsorption procss (L) and M is th mass of nm laf powdr (g). In th kintic study, th MB rmoval pr wight of adsorbnt at th quilibrium namd q which obtaind from quation (3) Cin C qt V M (3) whr C is th concntratin of rsidual MB at th quilibrium. This could b found from th kintic plot. III. RESULTS AND DISCUSSION 3.1 Effct of raction condition Th ffct of th initial MB concntration to th MB rmoval is shown in Figur 1. Th MB initial concntration was varid btwn 1 x x 10-6 M, th rsultd % MB rmoval was slightly dcrasd from 96.5% to 93.5% which sm constant. Th rsults xhibitd that th nm laf powdr was on of th ffctiv adsorbnt bcaus th % dy rmoval was almost 100% whn using th adsorbnt only 1.2 g/l at ph 10. Ponnusami and co-workrs also studid th ffct of initial dy concntration to MB adsorption ovr tak laf powr [14]. Thy varid th concntration of fflunts btwn 10-50% (by vol.) and corrlatd th dy rmoval to th COD lvl. Thy found a similar rsult to ours that at high initial dy concntration lss MB rmoval was obsrvd. Morovr, various studid also found that at low concntration of initial dy concntration rsultd in th high prcntag of dy rmoval [15-17]. This indicatd that th lack of activ sits for dy adsorption at high dy concntration which rsultd in dcrasing prcntag of dy rmoval at high dy concntration. Thrfor, to incras th % of dy rmoval, th adsorbnt containd high activ sit was rquird. Howvr, th actual amount of dy absorbd pr unit of adsorbnt mass wr incrasd with th incrasd of initial dy concntration [14-17] with in agrmnt with our rsults. Th prcntag of MB rmoval was incrasd with th nm laf powdr incrasd and rachd almost 100% dy rmoval whn using adsorbnt only 2 g/l. Th dosag of nm laf powdr was varid btwn g/l and th rsultd rmoval powr was % whn adsorption study was run at ph 10 and MB concntration was 4 x 10-5 M. This finding could b du to th incrasing of th surfac ara and th activ sits for dy adsorption whn incrasing th dosag and th rsults wr in th agrmnt with [17-18]. Howvr, thr was th optimum valu bcaus th initial dy concntration was fixd. Th rsultd in Figur 2 still suggstd that th nm laf powdr was th good adsorbnt for MB rmoval. Th adsorption of th targt dy ovr th surfac of adsorbnt is th ky raction in MB rmoval. Th MB is th cationic dy, thrfor, th adsorption of MB is strongly dpnd on th surfac charg of adsorbnt. Th considration of th surfac charg of adsorbnt is rlatd dirctly to th ph of solution. Thus, th ffct of th ph to th dy rmoval fficincy was takn into account. Figur 3 showd th ffct of ph which varid btwn Th prcntag of MB rmoval was incrasd from 50 to 80% at th studid ph rang. Th rsults showd that th ph in basic rang is favour for th MB adsorption ovr nm laf powdr. Th similar findings wr xhibitd in Sharma and K. G. Bhattacharyya [19] and Gusmao t al. [20]. Th Cd 2+ rmoval by using nm laf powdr was studid [19]. Th ffct of ph was also invstigatd and showd that at acidic ph btwn xhibitd no Cd 2+ rmovd. Whn ph changd to 4, about 9% of Cd 2+ liminatd and ph 9.5 could rmov about 94%. Thy xplaind that at low ph thr was th comptition btwn H + and Cd 2+ to adsorb at th activ sit whras th phnomna was rducd at alkalin ph and facilitatd th Cd 2+ adsorption by OH -. Gusmao t al. [20] also studid th adsorption of cationic (MB) dy and anionic dy (gntian violt, GV) ovr sugarcan bagass. Th ph was varid btwn 2-10 and th rsults wr showd that at acidic ph was suitabl for th anionic dy and alkalin ph was favour for cationic dy adsorption. This was supportd that th H + at low ph could dcorat th surfac of adsorbnt and rsultd in th dcoratd adsorbnt suitabl for anionic dy. On th othr hand, th OH - in alkalin ph was modifid th adsorbnt surfac and facilitatd th adsorption of cationic dy. According to our finding, th possibl adsorption of MB in alkalin rgion could xprssd as; Nm laf powdr + OH - Nm laf powdr-oh - + MB + Nm laf powdr-oh - MB + Th tmpratur is also th important factor to intrfr th adsorption fficincy. Th various tmpraturs wr opratd in th MB adsorption onto th nm laf powdr and th rsults wr xprssd in Figur 4. Th obvious rsults wr found as th highr tmpratur was facilitatd th adsorption fficincy; whn th tmpratur incrasd from C th adsorption was growth from 70-90%. Thrfor, it could b implid that th MB adsorption ovr nm powdr was th xothrmic procss. Th ffct of tmpratur of th Brilliant grn adsorption on th nm laf powdr was also studid and in agrmnt with our prsnt study [21]. Thy suggstd that high tmpratur th activation of th surfac groups such as alcoholic, carboxylic and phnolic groups wr found and ths was raisd th intraction of ths surfac groups and th OH - in solution. Thrfor, th highr ngativ surfac charg of adsorbnt was achivd, ladd to th highr adsorption capacity to MB. Morovr, th mass transfr cofficint was also incrasd at highr tmpratur which pushd mor dy molculs to b closr to th adsorption sit.

3 Intrnational Journal of Scintific and Rsarch Publications, Volum 4, Issu 10, Octobr Adsorption isothrm Langmuir and Frundlich isothrms wr applid to dtrmin th adsorption modl of MB onto MgO. Ths isothrms hav bn slctd to b a modl for invstigation th phnomna of MB adsorption ovr th nm laf powdr bcaus th Langmuir isothrm is illustratd th monolayr adsorption. This modl basically assumd that th adsorption occurrd on homognous surfac and th surfac containd th idntical adsorption sits. Morovr, ach of adsorption sit can adsorbd only 1 adsorbing molcul (rlatd to monolayr adsorption) and thr is no intraction btwn th adjacnt of adsorbd molcul. Th Langmuir quation is shown in quation (3-4) [22]: q Q K C KC 0 L 1 L (3) Th rciprocal quation of quation (3) can b xprssd as follows and illustratd in linar form: C 1 1 C q Q K Q 0 L 0 (4) Q 0 (mg/g) is th maximum adsorption capacity of th dy (monolayr formation) pr gram of adsorbnt. K L is a Langmuir constant rlatd to th affinity of th binding sits (l/mg) or th fr nrgy of adsorption. Th plot of C /q vs. C was showd in Figur 6 (a). Th Frunlich isothrm is xhibitd th multilayr adsorption ovr th adsorption sits. This modl is th xtntion of th assumptions in Langmuir isothrm for achiving th 1 n. Th imprfction of th surfac morphology by th factor of assumption was mntiond in th surfac roughnss, inhomognity and adsorbat-adsorbat intractions which dscribing rvrsibl adsorption. Thus, this could b implid that th adsorption could b th physical adsorption. Th mpirical Frundlich isothrms is also shown in quation (5) [23] q K C 1/n f (5) Th logarithmic form of this quation can b xprssd as: 1 ln q ln K ln C n f (6) whr K f and n ar th Frundlich constants which rlatd to th adsorption capacity and th adsorption intnsity of adsorbnt. ln q Th rlationship btwn ln C and is a linar plot according to quation (6) shown in Figur 6 (b). Th corrlatin cofficint (R 2 ) could b usd to indicat wll fittd of xprimntal data. Th rlationship btwn prcntag of MB rmoval and raction tim known as kintic plots wr shown in Figur 5 (a) and (b); undr th dpndnc of phs and tmpraturs, rspctivly. Th rsults confirmd that th alkalin ph was nhancd th MB rmoval and high tmpratur was th favor condition for th MB adsorption procss ovr nm laf powdr. From ths plots, th data was furthr analyzd to classify th typ of adsorption isothrm and raction ordr. According to quation (4), th curv of C /q vs. C was plottd to xamin th Langmuir isothrm which showd in Figur 6 (a). Th lvl of wll fitting to Langmuir isothrm was considr with rspctd to th corrlation cofficint valu (R 2 ) as th plottd rlationship was th linar typ: rfrrd to quation (4). Figur 6 (c) showd linar quation and R 2 of Langmuir plot of th adsorption procss opratd at ph 10. Similarly, th curv in Figur 6 (b) was th Frunlich isothrm plot as rfrd to quation (6) and Figur 6 (d) also showd th linar fittd quation and R 2 of th raction at ph 10. Th comparison of R 2 in Figur 6 (c) and (d) showd that R 2 of Langmuir isothrm was highr than Frunlich isothrm; indicatd that this procss fittd wll with Langmuir isothrm. Th R 2 of adsorption isothrm invstigation (in both th ffct of ph and tmpratur) showd in Tabl 1 and 2. Th rsults wr in agrmnt that R 2 of Langmuir isothrm was highr than Frunlich isothrm, thrfor, clarly confirmd that th MB rmoval by nm laf powdr was followd th Langmuir isothrm From th slop of Langmuir plot, th maximum adsorption capacity (Q 0 ) of nm laf powdr could b calculatd. Th Q 0 was calculatd from th optimum condition (at ph 10 and 70 C) and showd Q 0 = mol/g. Tabl 3 showd Q 0 of MB on various natural adsorbnt. Howvr, th Q 0 ovr nm laf powdr was studid bfor [13]. Th comparison Q 0 in 2 studis wr compard which showd clarly diffrnt; 2.35 x 10-5 mol/g [13] and 1.67 x 10 mol/g (this study). Th diffrnt of ths 2 adsorption procsss was th raction condition such as ph and tmpratur. Thrfor, it suggstd that th condition during th adsorption procss playd th vital rul in th rmoval capacity of this kind of adsorbnt. Th similarly rsults wr also found in th prvious studis such as Han t al [12] and Awwad t al [29]. Th adsorption isothrm of MB onto lotus laf powdr was xamind [12] and Langmuir isothrm was found to b fitting wll with th adsorption systm by xprssd high R 2 (0.9910). Morovr, Th Cd 2+ bioadsorption ovr loquat lav powdr was also studid and th xprimntal data was rlatd to th Langmuir adsorption at R 2 = whras R 2 of Frunlich isothrm was only Adsorption kintic study Th Psudo ordr approximation usd to xplain th raction which contains at last on xcss componnt and th adsorption rat of th xcss componnt is constant. Psudo-first-ordr kintic modl assum that th adsorbat uptak to th surfac with tim was dirctly proportional to diffrnc in saturation concntration and th adsorbnt amount [24]: dqt dt 1 k q q t (7) q and q t ar th amount of dy adsorbd (mg/g) at quilibrium and at tim t, rspctivly. And k 1 is th rat constant of Psudo-first-ordr (min -1 ).

4 Intrnational Journal of Scintific and Rsarch Publications, Volum 4, Issu 10, Octobr Equation (7) was intgratd with th boundary condition at t=0, q t = 0 and at t=t, q t =q t and rarrangd th quation to obtain quation (8) log q q log q Similar with t q q 1 t kt kt 1 Whn th xprimntal data was plottd btwn q t and t and th shap of th xprssd rlationship is in xponntial curv as shown in quation 9. This indicatd that th adsorption is followd th psudo-first ordr. Th rsultd curvd was shown in Figur 7 (a). In trm of th Psudo-scond-ordr modl with proposd by McKay and Ho in 1999 [25] was: dqt dt 2 2 k q q t (8) (9) (10) whr k 2 is th quilibrium rat constant of Psudo-scond ordr adsorption (g/mg min). Similarly to psudo-first-ordr, quation 10 was intgratd with similar condition boundary to obtain quation (11): t 1 t q k q q 2 t 2 (11) Th substantiation of th Psudo-scond ordr kintic modl t q was th plot of t and t. If th trnd is followd th linar rlationship of quation 11, it suggstd that th adsorption procss is th psudo- scond ordr. Th kintic modl was invstigatd by using th curvs in Figur 7 (a) and (b). Th rlationship of q t and t (Figur 7 (a) and (c)) was th psudo-1 st ordr plot and th obtaind plot was not followd th xponntial as typ of quation (9). This could b implid that th adsorption procss was not th psudo-1 st ordr raction. In othr hand, th plots of t and t (in Figur 7 (b) and (d)) wr th psudo-2 nd ordr plot which was th linar rlationship. Similarly, th wll fitting was considrd by R 2. Th obtaind R 2 of th psudo-2 nd ordr which studid th ffct of ph and tmpratur ffct wr rportd in Tabl 1 and 2. Thy wr all in agrmnt and found that R 2 was closly to 1 ( ). This was indicatd that adsorption was fittd wll with th psudo-2 nd ordr. Rfr to quation 11, th intrcption of psudo-2 nd ordr plot could b calculatd to obtaind k 2 and it showd k 2 = 1.19 x 10 5 g/mg min. Th obtaind k 2 could b suggstd that th adsorption is favor occurrd. t q IV. CONCLUSIONS Th optimum condition of MB rmoval using nm laf powdr was invstigatd. Th rsults found that th rmoval was favour at low MB concntration, highr ph and highr tmpratur. Th optimum loading of adsorbnt was 1.2 g/l. Th xprimntal data was fittd with Langmuir isothrm bttr than Frulich isothrm in both ph and tmpratur dpndncs. This was suggstd that th adsorption was monolayr adsorption with th chmisorptions. Morovr, th kintic analysis in both th ph and tmpratur ffct was in agrmnt; showing that th psudo scond-ordr procss was fittd with th data. ACKNOWLEDGEMENTS I would lik to thank Faculty of Scinc, Mahasarakham Univrsity for financial support. Th authors acknowldg dpartmnt of Chmistry, Faculty of scinc, Mahasarakham Univrsity. And som financial support from th Cntr of Excllnc for Innovation in Chmistry (PERCH-CIC), Offic of th Highr Education Commission, Ministry of Education is gratfully acknowldgd. REFERENCES [1] B.S. Inbaraj, N. Sulochana, Us of jackfruit pl carbon (JPC) for adsorption of rhodamin-b, a basic dy from aquous solution, Ind. J. Chm. Tchnol 13 (2006) 1. [2] T. Robinson, B. Chandran, P. Nigam, Rmoval of dys from a synthtic txtil dy fflunt by biosorption on appl pomac and what straw, Watr Rs. 36 (2002) [3] C. Namasivayam, N. Muniasamy, K. Gayatri, M. Rani, K. Ranganathan, Rmoval of dys from aquous solutions by cllulosic wast orang pl, Bio-rsour Tchnol. 57 (1996) 37. [4] K.S. Low, C. K. L, K.K. Tan, Biosorption of basic dys by watr Hyacinth roots, Biors. Tchnol 52 (1995) 79. [5] M.I. El-Khaiary, Kintics and mchanism of adsorption of mthyln blu from aquous solution by nitric-acid tratd watr-hyacinth, J. Hazard. Matr. 147 (2007) 28. [6] F. Banat, S. Al-Ashh, L. Al-Makhadmh, Evaluation of th us of raw and activatd dat pits as potntial adsorbnts for dy containing watrs, Proc. Biochm. 39 (2003) 193. [7] M. Dogan, M. Alkan, Y. Onganr, Adsorption of mthyln blu from aquous solution onto prlit, Watr Air Soil Pollut. 120 (2000) 229. [8] V. Vadivlan, K.V. Kumar, Equilibrium, kintics, mchanism, and procss dsign for th sorption of mthyln blu onto ric husk, J Colloid Intrfac Sci.286 (2005) 90. [9] R. Gong, M. Li, C. Yang, Y. Sun, J. Chn, Rmoval of cationic dys from aquous solution by adsorption on panut hull, J. Hazard. Matr B121 (2005) 247. [10] M.M. Nassar, Intraparticl diffusion of basic rd and basic yllow dys on palm fruit bunch, Watr Sci. Tchnol. 40 (1999) 133. [11] V.K. Garg, R. Gupta, A.B. Yadav, R. Kumar, Dy rmoval from aquous solution by adsorption on tratd sawdust, Biorsour. Tchnol. 89 (2003) 121 [12] C. Namasivayam, R. Radhika, S. Suba, Uptak of dys by a promising locally availabl agricultural solid wast: coir pith, Wast. Manag. 21 (2001) 381. [13] K.G. Bhattacharyya, A. Sharma, Kintics and thrmodynamics of mthyln blu adsorption on nm (Azadirachta indica) laf powdr, Dys Pigmnts 65 (2005) 51. [14] V. Ponnusami, S.N. Srivastava, Studis on application of tak laf powdrs for th rmoval of color from synthtic and industrial fflunts, J. Hazard. Matr. 169 (2009) 1159.

5 Intrnational Journal of Scintific and Rsarch Publications, Volum 4, Issu 10, Octobr [15] N.K. Amin, Rmoval of dirct blu-106 dy from aquous solution using nw activatd carbons dvlopd from pomgranat pl: Adsorption quilibrium and kintics, J. Hazard. Matr. 165 (2009) 52. [16] I.D. Mall, V.C. Srivastava, N.K. Agarwal, Rmoval of Orang-G and Mthyl Violt dys by adsorption onto bagass fly ash- kintic study and quilibrium isothrm analyss, Dys Pigmnts 69 (2006) 210. [17] N.K. Amin, Rmoval of ractiv dy from aquous solutions by adsorption onto activatd carbons prpard from sugarcan bagass pith, Dsalination. 223 (2008) 152. [18] X. Han, W. Wang, X. Ma, Adsorption charactristics of mthyln blu onto low cost biomass matrial lotus laf, Chm. Eng. J. 171 (2011) 1. [19] A. Sharma, K.G. Bhattacharyya, Azadirachta indica (Nm) laf powdr as a biosorbnt for rmoval of Cd(II) from aquous mdium, J. Hazard. Matr. 125 (2005) 102. [20] K.A.G. Gusmao, L.V.A. Gurglb, T.M.S. Mloa, L.F. Gila, Application of succinylatd sugarcan bagass as adsorbnt to rmov mthyln blu and gntian violt from aquous solutions Kintic and quilibrium studis, Dys. Pigmnts. 92 (2012) 967. [21] K.G. Bhattacharyya, A. Sarma, Adsorption charactristics of th dy, Brilliant Grn, on Nm laf powdr, Dys Pigmnts 57 (2003) 211. [22] E.N. El-Qada, S.J. Alln, G.M. Walkr, Adsorption of mthyln blu onto activatd carbon producd from stam activatd bituminous coal: a study of quilibrium adsorption isothrm, Chm. Eng. J.124 (2006)103. [23] N. Gupta,A.K. Kushwaha, M.C. Chattopadhyaya, Adsorption studis of cationic dys onto Ashoka (Saraca asoca) laf powdr, J. Taiwan Inst. Chm. Eng. 43 (2012) 604. [24] S. Lagrgrn, Zur thoris dr sognanntn adsorption glostr stoff, Kungliga Svnska Vtnskapsadmins, Handlingar 24 (1898) 1. [25] Y.S. Ho, G. Mckay, Psudo-scond ordr modl for sorption procss, Procss Biochm, 34 (1999) 451. [26] C.H. Wng, Y.T. Linb, T.W. Tzngb, Rmoval of mthyln blu from aquous solution by adsorption onto pinappl laf powdr, J. Hazard. Matr. 170 (2009) 417. [27] G. McKay, J.F. Portr, G.R. Prasad, Rmoval of dy colours from aquous solu-tions by adsorption on low-cost matrials, Watr Air Soil Pollut. 114 (1999) 423. [28] G. Annadurai, R.L. Juang, D.J. L, Us of cllulos-basd wasts for sorption of dys from aquous solutions, J. Hazard. Matr. 92 (2002) 263. [29] A.M. Awwad and N.M. Salm, Kintics and thrmodynamics of Cd(II) biosorption onto loquat (Eriobotrya japonica) lavs., J. Saudi. Chm. Soc. (2011) (Articl in prss). AUTHORS First Author Kornwipha Sangbutr, Th Cntr of Excllnc for Innovation in Chmistry and dpartmnt of Chmistry, Faculty of Scinc, Mahasarakham Univrsity, Kantarawichai District, Mahasarakham 44150, Thailand Scond Author Nittaya Wangphon, Th Cntr of Excllnc for Innovation in Chmistry and dpartmnt of Chmistry, Faculty of Scinc, Mahasarakham Univrsity, Kantarawichai District, Mahasarakham 44150, Thailand Third Author Ratchankorn Wanchanthuk, Th Cntr of Excllnc for Innovation in Chmistry and dpartmnt of Chmistry, Faculty of Scinc, Mahasarakham Univrsity, Kantarawichai District, Mahasarakham 44150, Thailand, Tl./ Fax , addrss: ratchankorn.p@msu.ac.th Figur 1 Effct of th initial MB concntration in MB adsorption onto nm laf powdr

6 Intrnational Journal of Scintific and Rsarch Publications, Volum 4, Issu 10, Octobr Figur 2. Effct of adsorbnt contnt in MB adsorption onto nm laf powdr Figur 3. Effct of ph in MB adsorption onto nm laf powdr

7 Intrnational Journal of Scintific and Rsarch Publications, Volum 4, Issu 10, Octobr Figur 4. Effct of tmpratur in MB adsorption onto nm laf powdr (a) (b) Figur 5. Kintic plot of th MB rmoval ovr nm laf powdr as (a) ph and (b) tmpratur dpndnc.

8 Intrnational Journal of Scintific and Rsarch Publications, Volum 4, Issu 10, Octobr (a) (b) (c) Figur 6 Th adsorption isothrm study of th MB rmoval, at MB concntration = 3.8 x 10-5 M and tmpratur 45 C (a) Langmuir, (b) Frundlich adsorption isothrms ovr various ph, (c) Langmuir and (d) Frundlich adsorption isothrm at ph = 10. (d)

9 Intrnational Journal of Scintific and Rsarch Publications, Volum 4, Issu 10, Octobr (a) (b) (c) Figur 7 Th kintic study of th MB rmoval, at MB concntration = 3.8 x 10-5 M and tmpratur 45 C (a) Psudo-first ordr, (b) Psudo-scond ordr ovr various ph, (c) Psudo-first ordr and (d) Psudo-scond ordr at ph = 10. Tabl 1 Effct of ph in adsorption isothrm and kintic modl fitting R 2 ph Langmuir Frundlich Psudo-1 st ordr Psudo-2 nd ordr Tabl 2 Effct of Tmpratur in adsorption isothrm and kintic modl fitting Tmpratur (C) Langmuir Frundlich Psudo-1 st ordr Psudo-2 nd ordr R 2 R 2 R 2 (d)

10 Intrnational Journal of Scintific and Rsarch Publications, Volum 4, Issu 10, Octobr Tabl 3 Comparison of adsorption capacity of MB on various natural adsorbnt Adsorbnts surfac ara (m 2 /g) ph Tmp. (C) Q 0 (mol/g) Rfs. Pinappl laf powdr x 10 4 [26] Ric husk NA NA x 10 4 [27] Cotton wast NA NA x 10 4 [27] Panut hull x 10 4 [9] Orang pl x 10-5 [28] Nm laf powdr NA NA x 10-5 [13] Nm laf powdr (yllow laf) NA x 10 This study