Studies on removal of methylene blue from aqueous solution using activated carbon derived from wood apple waste biomass by microwave irradiation

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1 IOSR Journal of Environmntal Scinc, Toxicology and Food Tchnology (IOSR-JESTFT) -ISSN: ,p- ISSN: Volum 12, Issu 7 Vr. II (July. 218), PP Studis on rmoval of mthyln blu from aquous solution using activatd carbon drivd from wood appl wast biomass by microwav irradiation M. Anu 1, C.Prmalatha 1, R. Malarvizhi 1* 1. Dpartmnt of Chmistry, Govrnmnt Arts Collg, Trichy-6222, India 2., Dpartmnt of Chmistry, Govrnmnt Collg, Trichy-6222, India Corrsponding Author: R.Malarvizhi Abstract: Th purpos of this study is prparation and charactrization of activatd carbon using wood appl rind wast biomass by microwav irradiation using two diffrnt acids lik sulphuric acid and phosphoric acid. A systmatic invstigation of th ffct of dos, ph and initial concntration was don. Th FT-IR analysis of th activatd carbon dpicts th prsnc of a varity of functional groups on it. Th ph of th dy solution plays a major rol in th adsorption procss and it is th most important factor compard to all othr factors that affct th adsorption procss. Kywords: Mthyln blu, Microwav ovn, wood appl rind, Langmuir isothrm Dat of Submission: Dat of accptanc: I. Introduction Watr pollution du to toxic mtals and organic compounds rmains a srious nvironmntal public problm for past fw dcads. Havy mtal ions, aromatic compounds including phnolic drivativs, polycyclic aromatic compounds and dys ar oftn found in th nvironmnt as a rsult of thir wid industrial uss. Thy ar common contaminants in wast watr and many of thm ar known to b toxic. Today mor than 3 dys ar in us worldwid 1. Many mthods ar availabl for th rmoval of dys from wastwatr such as coagulation, solvnt xtraction, catalytic dgradation and chmical oxidation 2,3. But ths mthods hav som drawbacks. Among ths mthods, adsorption tchnology is on of th attractiv mthods du to its salint faturs such as cost ffctivnss, fficincy, co-frindlinss and as of rcovry 4. Many industris ar mploying adsorption tchniqu and prfr to us activatd carbon for th rmoval of various pollutants from fflunts. This is bcaus of th high adsorption control, highly porous natur of th matrial and high surfac ara. Th activatd carbon can b prpard using chmical activating agnts such as H 3 PO 4, NaOH, KOH, H 2 SO 4 or ZnCl 2. Activatd carbon has bn usd for various industrial applications lik adsorption of H 2 S 5, dys 6,7.Activatd carbon is an xcllnt adsorbnt that is usd to rmov diffrnt organic and inorganic pollutant from many aquous solutions. Various agricultur wast or cllulos matrials such as cotton stalk, dat stons, ric husks, apricot stons, oliv stons, and almond shlls ar usd to prpar activatd carbon 8,9. Th slction of activation mthod and raw matrials ar important in controlling th physical and chmical charactrization of th prpard activatd carbon 1,11. Th us of th thrmal hating is to nhanc th surfac chmistry and structur of pors 12,13. Microwav procssing of matrial is a tchnology that can provid a nw, powrful, and significantly diffrnt tool to procss matrials or to improv th prformanc charactristics of xisting matrials. 14,15 Compard with convntional mthods, this hating offr many advantags including shortr synthsis tim, rapid hating, fast raction, asy rproducibility, narrow particl distribution, high yild, high purity, fficint nrgy transformation. Elctricity consumption can b rducd by mor than half by using microwav assistd sintring 16. In rcnt yars, microwav has mrgd as a promising altrnativ nrgy sourc for th hating matrials. II. Matrials And Mthods Th wast biomasss obtaind from wood appl rind was crushd into small pics and soakd with phosphoric acid (H 3 PO 4 ) in 1: 1 ratio (w/v) for 48 hours to yild a black carbon product. Thn it was kpt in a microwav ovn maintaind at 8 watts for 4 minuts. It was thn washd thoroughly with distilld watr until th ph of th wash watr bcoms th ph of th distilld watr. Th wt product obtaind was drid at 15 5 C. Th carbonacous adsorbnt is ground and sivd. Th adsorbnt obtaind aftr phosphoric acid tratmnt was dsignatd as MPWAC. Th abov procss is rpatd with sam quantity of sulphuric acid and th carbon obtaind was dsignatd as MSWAC. A stock solution of mg/l of Mthyln blu dy was prpard using DOI: 1.97/ Pag

2 %T %T c m c m - 1 distilld watr. Batch mod xprimnts wr conductd in scrw cap bottls of 2 ml capacity. Hundrd millilitr of th solution containing prdtrmind concntration of th MB dy undr invstigation was takn in th bottls. Th ph of th dy solution was adjustd by using digital ph mtr ELIGO digital modl. Aftr th addition of known amount of adsorbnt, th bottls wr quilibratd for a prdtrmind priod of tim in a mchanical shakr at 12 rpm. At th nd of th quilibration priod, using micro filtrs, th dy solution is takn and th concntration of rsidual MB in solution was dtrmind. Th functional groups availabl on th surfac of MPWAC and MSWAC wr dtctd using FT-IR analysis. Th surfac morphology of MPWAC and MSWAC was charactrizd using Scanning Elctron Microscop. Th ffct of initial dy concntration was studid by varying th initial MB dy concntrations from 1 ppm to ppm for th optimizd adsorbnt dosag (.1g). III. Rsults And Discussion Charactrization of adsorbnts Tabl 1: Paramtr MPWAC MSWAC ph Moistur contnt(%) Ash contnt(%) Watr solubl mattr(%) Acid solubl mattr(%) Iodin numbr(mg/g) Dcolourising powr(mg/g) 3 Bulk Dnsity(g/cc) Zro Point Charg FT-IR analysis: Th FT-IR spctroscopic study of MPWAC and MSWAC activatd carbons ar shown in Figur 1, 2. Th spctrum showd four major absorption bands at 34 cm -1, 16 cm -1, 14 cm -1 and 6cm -1 rang. Th band at 34 cm - 1 is du to th absorption of watr molculs as rsult of an O-H strtching mod of hydroxyl groups and adsorbd watr, whil th band at 2 is attributd to C-H intraction with th surfac of th carbon. Howvr, it must b indicatd that th bands in th rang of 32-36cm -1 hav also bn attributd to th hydrogn-bondd OH group of alcohols and phnols. Th band at 6- cm -1 is attributd to C-Cl group. Th band at cm -1 may also b attributd to th aromatic carbon-carbon strtching vibration. Th intns band around 16 cm 1, may b du to asymmtric and symmtric strtching COO vibrations or to skltal C=C aromatic vibrations. Bands apparing in th rang of 16 cm 1 wr also attributd to vibrations in iono-radical structurs. O. Th iono-radical structur cm cm cm cm cm cm cm cm cm cm cm cm cm Fig 1: FT-IR spctrum of MPWAC cm-1 Nam Dscription IR-WAC-PM cm-1 Nam Dscription IR-WAC-SM- Fig 2: FTIR spctrum of MSWAC DOI: 1.97/ Pag

3 Adsorption capacity, (mg/g) % Rmoval Adsorption capacity, (mg/g) % Rmoval SEM Analysis: Th scanning lctron micrographs of plain MPWAC and MSWAC obtaind ar shown in Fig 3&4. Th figurs clarly dpict th siz, surfac txtur and porosity of carbons. A numbr of hols and small opnings, calld micro pors and widning of por siz at microns ar found on th surfac of th carbons. Fig 3: SEM imags of MPWAC Fig 4: SEM imags of MSWAC Effct of carbon dosag: Th ffct of adsorbnt dosag was studid by varying th adsorbnt dosag from.2g/l to 2.5g/L. From th fig 5&6 it was obsrvd that th prcntag adsorption of MB dy incrasd with an incras of th carbon dosag. Th maximum % of adsorption of MB was found to b MPWAC is 93.6 % and MSWAC is 96.4% at a dosag of 2.5 g/l Dos, (g/l) Fig 5: Dos ffct of MPWAC Dos, (g/l) Fig 6: Dos ffct of MSWAC Effct of initial aquous ph on adsorption Initial aquous phas ph plays an important rol in th liquid-phas adsorption capacity. Th ph of th solution is th most important factor compard to th all othr factors that affct th adsorption procss. In MSWAC-MB systm, th incras of ph of th solution incrass th adsorption of MB dy from solution. Initial rat of adsorption is mainly dcidd by th protons rlas from carbon surfac du to ion xchang procss which is confirmd by th masurmnt of ph of th solution aftr th adsorption procss. (Th ph of th solution dcrasd to th ph in th rang of ). At acidic ph, th adsorption of th dy is low and upto ph 7 and thn th adsorption capacity of MSWAC is found to b highr at ph 9 at highr ph th protons ar nutralizd with OH ions so th adsorption procss incrass. But in MPWAC-MB systm, th % rmoval of th dy incrasd from 77% to 86% (upto 7.5) thn aftr ph 7.5 adsorption of th dy is dcrasd. Lowr amount of MB dy was adsorbd onto th prpard DOI: 1.97/ Pag

4 adsorbnts at acidic ph and thn incrasd sharply upto ph 7 thn it dcrass. Th amount of MB adsorbd is dcrasd aftr ph 7, th rduction in adsorbd amount of MB aftr ph 7 may b ascribd to th incrasing rpulsiv forcs btwn surfac functional groups of adsorbnt and cationic MB dy that mainly xists as anion form [17]. Basically, mthyln blu and othr cationic dys produc an intns molcular cation (C + ) Adsorption Isothrm Th ffct of initial dy concntration was studid by varying th initial MB dy concntrations from 1 ppm to ppm for th optimizd adsorbnt dosag (.1g). This study was furthr xtndd to calculat quilibrium paramtrs using linar form of isothrm modls such as Langmuir and Frundlich isothrms Langmuir isothrm Th Langmuir quation is applicabl to homognous adsorption and it is basd upon th assumption of monolayr adsorption, whr th adsorption of ach adsorbat molcul onto th surfac has qual sorption activation nrgy. Th linar form of this isothrm is rprsntd by th xprssion 18 C / q 1/ qb C / q Whr, q (mg/g) and C (mg/l) ar th amount of adsorbd adsorbat pr unit wight of adsorbnt and unadsorbd adsorbat concntration in solution at quilibrium rspctivly. K a (L/mg) is th Langmuir quilibrium constant and th maximum monolayr adsorption capacity (q m ) was found to b MPWAC is 63 mg/g (quilibrium tim=3 hrs).and MSWAC is 66 mg/g(quilibrium tim=2 hrs). Frundlich isothrm Th most important multisit adsorption isothrm for th non-idal adsorption on htrognous surfacs is th Frundlich adsorption isothrm and th linar form of this isothrm is xprssd as 19 log q log K F logc 1 n Frundlich constant K f indicats th adsorption capacity also rprsnts th strngth of th adsorptiv bond and n is th htrognity factor which also rprsnts th bond distribution.. DOI: 1.97/ Pag

5 C/q, (g/dm3) log(q ) C, (mg/dm3) log(c ) Fig 11&12: Langmuir & Frundlich isothrm modl MPWAC For both carbons th incras in initial concntration of dy solution incrasd th adsorption capacity. Th xprimntal rsults ar givn in Tabl 2&3. From th Figs 9, 1, 11 & 12, it is clar that th adsorption of basic dy (MB) on MPWAC & MSWAC follows Langmuir modl. So th rmoval of basic dys from aquous solution by activatd carbon obtaind from wood appl rind wast biomass givs monolayr covrag and th adsorption is mainly du to Chmisorptions. This is confirmd by th dsorption studis also. Thr is no dsorption of MB dy from loadd carbon from th solution. It is carrid out by MB loadd carbon at various ph from 3 to 1. Th Langmuir constant, K a, rvals that MB is bound strongly on both MPWAC & MSWAC. Highr th K a valu, strongr is th affinity btwn th carbon surfac and th dy molculs. Th fittd isothrm paramtrs ar givn in Tabl 2. Tabl 2: Fittd isothrm paramtrs for MPWAC systm at ph 7 Isothrm modl Paramtrs Units MPWAC MSWAC Langmuir q m mg/g K a L/mg.57. Frundlich r 2 K F 1/n r g/l IV. Conclusion Systmatic batch mod studis wr carrid out to find out th ffct ph on rmoval of MB using MPWAC and MSWAC. Th activatd carbon prpard from wood appl rind wast by using sulphuric acid and phosphoric acid by microwav irradiation activation mthod can b usd for wastwatr tratmnt. Th adsorption capacity is rasonably high for both th carbons. Through th IR spctrum of both th carbons, th functional groups prsnts on th surfac of th carbon is idntifid. From th SEM imags at various magnifications of MPWAC & MSWAC shows th siz of th pors prsnt on th surfac. Th adsorption quilibrium data fits into th Langmuir isothrm modl which indicats monolayr adsorption. Exprimntal rsults of th prsnt invstigation showd that MPWAC and MSWAC is a potntial adsorbnt for th rmoval MB from aquous solution ovr a wid rang of concntrations. Rfrnc [1]. Barns D, C.F. Forstry and S.E. Hrudy ds, Survys in industrial wast watr tratmnt Ptrolum and organic chmicals industris, Longman scintific and tchnical, Longman group, UK, [2]. L. Liang, M. Horvat, E. Crnichiari, B. Glin, S. Balogh, Simpl solvnt xtraction tchniqu for limination of matrix intrfrncs in th dtrmination of mthylmrcury in nvironmntal and biological sampls by thylation-gas chromatographycold vapor atomic fluorscnc spctromtry, Talanta,1996, 43,pp [3]. V.K. Gupta, R. Jain, A. Mittal, T.A. Salh, A. Nayak, S. Agarwal, S. Sikarwar, Photo-catalytic dgradation of toxic dy amaranth on TiO 2/UV in aquous suspnsions, Matrials Scinc and Enginring C, 212, 32,pp DOI: 1.97/ Pag

6 [4]. Crini, Rcnt dvlopmnts in polysaccharid-basd matrials usd as adsorbnts in wastwatr tratmnt. Prog. Polym. Sci, 25, 3, pp. 38. [5]. M.P Cal, B.W Stricklr, A.A Lizzio, High tmpratur hydrogn sulfid adsorption on activatd carbon, Effcts of gas composition and mtal addition, carbon,25, 38, pp [6]. P.K. Malik, Dy rmoval from wastwatr using activatd carbon dvlopd from sawdust: adsorption quilibrium and kintics, Journal of Hazardous Matrials, 25,113, pp [7]. Annadurai, R.S. Juang, D.J. L, Us of cllulos-basd wasts for adsorption of dys from aquous solutions, Journal of Hazardous Matrials,22, 92, pp [8]. Daifullah, A.A.M. Girgis, B.S. Gad, H.M.H. Utilization of agro rsidus (ric husk) in small wast tratmnt plans. Matrial lttrs,23,57, pp [9]. Sulyman, M. O. Abudaia, J. A. AlAzabi, Kh. Y, Adsorption of CO 2 by Activatd Carbon from Dat Stons Filld into a Local Dsign of Automobil Exhaust, GSTF Intrnational Journal of Enginring Tchnology,213,2 [1]. Josfa, M.A. Pdro, V. GomzSrrano, Oxidation of activatd carbon by fry and wt mthods: Surfac chmistry and txtural Modifications. Ful Procss Tchnol,21, 91(11), pp [11]. Hui-Hsin., T. W. Ming-Yn, Effcts of acid tratmnts of activatd carbon on its physiochmical structur as a support for coppr oxid in D SO 2 raction catalysts. Chmosphr,26, 62(5), pp [12]. Ohkubo, T. Yang, C.M. Raymundo-Pinro, E.S. Kanko, L.K, High-tmpratur tratmnt ffct of microporous carbon on ordrd structur of confind SO 2. Chm. Phys. Ltt,2, 329 (1-2), pp [13]. Boudou J.P, Chhimi, M. Bronik, E. Siminiwska, T. Bimr, J, Adsorption of H 2S or SO 2 on an activatd carbon cloth modifid by ammonia tratmnt. Carbon,23, 41(1), pp [14]. Mjoo.S., Manprakorn, W.and Winotai, P,Phas and Thrmal Stability of Nanocrystallin Hydroxyapatit prpard via Microwav hating. Thrmochimica Acta, 26,447, pp [15]. Das S., Mukhopadhayay, A.K Datta S And Basu D, Prospcts of Microwav Procssing: An ovrviw. Bulltin of Matrials scinc, 26, 32, pp [16]. Shulman S, Fall, M.L. and Strickland P, Cramic Procssing using microwav Assist Tchnology. Amrican Cramic socity Bulltin, 28, 87, pp [17]. Rodríguz.A, J. García, G. Ovjro, and M. Mstanza, Adsorption of anionic and cationic dys on activatd carbon from aquous solutions: quilibrium and kintics, Journal of Hazardous Matrials,29, 172, pp [18]. Langmuir, Th adsorption of gass on plan surfacs of glass, mica and platinum. x. J. Am. Chm. Soc, 1918,4, pp [19]. Frundlich,. H., J. Z Phys. Chm,16, 57, pp R.Malarvizhi "Studis on rmoval of mthyln blu from aquous solution using activatd carbon drivd from wood appl wast biomass by microwav irradiation "IOSR Journal of Environmntal Scinc, Toxicology and Food Tchnology (IOSR-JESTFT) 12.7 (218): DOI: 1.97/ Pag