Zinc Chloride-activated Waste Carbon Powder for Decolourization of Methylene Blue

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1 Jurnal Tknologi Full papr Zinc Chlorid-acivad Was Carbon Powdr for Dcolourizaion of Mhyln Blu Muhammad Abbas Ahmad Zaini a*, Ting Chiw Ngiik a, Mohd. Johari Kamaruddin a, Sii Hamidah Mohd. Sapar a, Mohd. Azizi Ch Yunus a a Cnr of Lipids Enginring and Applid Rsarch (CLEAR), Univrsii Tknologi Malaysia, UTM Johor Bahru, Johor, Malaysia *Corrsponding auhor: abbas@chm.um.my Aricl hisory Rcivd :1 Ocobr 2013 Rcivd in rvisd form : 17 Novmbr 2013 Accpd :27 January 2014 Graphical absrac Absrac Was carbon powdr from pyrolysis of discardd yr was convrd ino acivad carbon for dcolourizaion of myln blu (MB). Th prcursor was acivad using ZnCl 2 (ZC), rcycld ZnCl 2 soluion from h arlir acivaion (RC), and irradiad war (MC). Acivad carbons wr characrizd according o surfac ara and morphology. Th valus of surfac ara wr rcordd as 288, 104 and 113 m 2 /g for ZC, RC and MC, rspcivly. Th dcolourizaion of MB was obsrvd o hav h following ordr: ZC>MC>RC. Th maximum adsorpion capaciy of MB by ZC was found o b 154 mg/g. Adsorpion daa for all acivad carbons sudid obyd Rdlich-Prson isohrm for which h procss could b dscribd as mixd faurs of Langmuir and Frundlich modls. Th kinics daa wr wllfid o psudo-scond-ordr modl, suggsing h chmisorpion procss. Kywords: Acivad carbon; irradiad war acivaion; mhyln blu; was carbon powdr; zinc chlorid acivaion 2014 Pnrbi UTM Prss. All righs rsrvd. 1.0 INTRODUCTION Th rlas of dys from xil indusris ino rciving war affcs h auaic craurs bcaus som dys ar highly oxic and carcinognic [1-3]. Dys block h passag of sunligh ino h sram, hus dsroy h lif cycl and food chain in war, and disrup h biodivrsiy wihin. Drioraing ualiy of war will also bring bad implicaions o public halh and daily lif. Mhyln blu (MB) is commonly usd in dying xil and mdicinal ramns [2-5]. I is no srongly hazardous bu can caus som harmful ffcs such as y injury, difficul brahing, nausa, vomiing, profus swaing, Hinz body formaion, diarrha, gasriis, mnal confusion, cyanosis, jaundic, issu ncrosis in humans and mhmoglobinmia [1-5]. Ths halh ffcs hav riggrd srong masur for MB rmoval as on of h major nvironmnal concrns. Mhods for dy rmoval includ adsorpion, chmical coagulaion, ion xchang, biological ramn and lcrolysis [2,3,6]. Of hs, adsorpion by acivad carbon is highly ffciv o rmov dy bcaus of h larg surfac ara and uniu xural propris of acivad carbon [7-8]. Howvr, acivad carbon prcursors lik coal and prolum pich ar no rnwabl, whil rgnraion of h spn acivad carbon is rlaivly xpnsiv. This scnario has rsuld in h sarchs for alrnaiv carbonacous prcursors ha ar abundanly availabl and low cos. On of h promising candidas undr his cagory is was carbon powdr, a pyrolysis by-produc of bulk was yr. Acivad carbon can b prpard hrough wo common rous, namly physical acivaion and chmical acivaion. Acivaing agns for physical acivaion ar CO2 and sam, whil chmical agns such as KOH, ZnCl2, H3PO4, K2CO3, c. ar commonly usd in chmical acivaion. Chmical acivaion is usually bing carrid ou a a lowr mpraur wihou carbonizaion, and usually rsuls in a highr yild compard o physical acivaion [9-12]. Th aim of his work was o invsiga h ponial of ZnCl2- acivad was carbon powdr for MB rmoval from auous soluion. Amps wr also mad o aciva h carbon by using rcovrd zinc chlorid soluion and irradiad war nvironmn. Th ffcs of iniial dy concnraion and agiaion im wr xamind and discussd. 2.0 EXPERIMENTAL 2.1 Marials All chmicals wr of analyical-ragn grad. Was carbon powdr was obaind from Buki Bau Brickmills (M) Sdn. Bhd. Mhyln blu (MB) was usd as h dy o b rad. Figur 1 67:2 (2014) ISSN

2 38 Muhammad Abbas Ahmad Zaini al. / Jurnal Tknologi (Scincs & Enginring) 67:2 (2014), shows h molcular srucur of MB, and is gnral propris ar lisd in Tabl 1. MB is a basic dy which carris a posiiv charg (caionic dy). Figur 1 Molcular srucur of mhyln blu Tabl 1 Characrisics of mhyln blu Chmical formula C 16H 18N 3SCl IUPAC nam 3,7-bis(Dimhylamino)- phnohiazin-5-ium chlorid Molar mass g/mol Colour indx numbr Wavlngh, λ 663 nm Solubiliy in war 1 g/25 ml 2.2 Prparaion of Acivad Carbon Th was carbon powdr was pr-rad a 250 C in furnac for abou 1.5h o rmov oil covring is surfac. Chmical acivaion: h prcursor was imprgnad wih ZnCl2 a imprgnaion raio (chmical agn ovr prcursor) of 1. Acivaion was prformd a 550 C for 1.5h in furnac. Th acivad carbon was washd using disilld war in a soxhl uni o rcovr ZnCl2. Th acivaion procdurs wr rpad using h rcycld ZnCl2 soluion o produc anohr acivad carbon. Acivad carbons wr dsignad as ZC and RC for acivaion using frsh and rcycld ZnCl2 soluion, rspcivly. Irradiad war acivaion: h prcursor was soakd in disilld war and acivad undr microwav a half magniud of powr innsiy for 20 minus. Th rsulan acivad carbon was dsignad as MC. Th acivad carbons wr drid in an ovn prior o characrizaion and adsorpion sudis. C 0 C m V whr C0 and C (mg/l) ar iniial and uilibrium concnraions, rspcivly, V (ml) is h volum of h soluion and m (g) is h mass of dry adsorbn. Euilibrium daa wr analyzd using h commonly usd isohrm modls, namly Langmuir, Frundlich and Rdlich-Prson modls. Adsorpion kinics: Acivad carbon ha dmonsrad h highs MB rmoval in uilibrium sudis was slcd for kinics valuaion. A fixd amoun of 0.1 g of acivad carbon was addd o diffrn bachs of 50 ml MB soluion having concnraions of 50 and 300 mg/l. Th rsidual concnraion was masurd a prs im inrvals for 72 hours. Kinics daa wr fid o psudo-firs ordr, psudo-scond ordr and inraparicl diffusion modls, and h rspciv consans wr drmind. 3.0 RESULTS AND DISCUSSION 3.1 Characrisics of Acivad Carbon Figur 2 rprsns h hrmogravimric profil of was carbon powdr bfor acivaion. (1) 2.3 Characrizaion of Acivad Carbon Thrmal profil of h prcursor was drmind undr N2 flow a a haing ra of 10 C/min by hrmogravimric analysis (TGA7, PrkinElmr). Th surfac ara of acivad carbon was masurd using surfac ara analyzr (Micromriics PulsChmiSorb 2705, USA), whil h surfac morphology was drmind using SEM insrumn (Philips XL 40, Nhrlands). 2.4 Adsorpion Sudis Euilibrium isohrms: Mhyln blu (MB) was mployd as h polluan prob in adsorpion. In bach adsorpion, 0.1g of acivad carbon was addd ino conical flasks conaining 50mL of MB of varying concnraions (50 o 300ppm). Th soluion ph was no adjusd, and masurd as 5.5±0.3 for all iniial concnraions sudid. Th flasks wr sald, and h mixurs wr allowd o uilibra on orbial shakr a 28±1 C and 90rpm for 72 hours. Thrafr, h soluions wr filrd and h rsidual concnraions wr drmind using Visibl Spcrophoomr (Biochrom Libra S6, UK) a a wavlngh of 690 nm. Th amoun of mhyln blu adsorbd a uilibrium, (mg/g), was calculad by simpl mass balanc, Figur 2 Thrmogravimric analysis of was carbon powdr bfor acivaion Th profil shows hr main rgions of considrabl wigh loss, i.., a mpraurs 300, 500 and 800 C. Th firs rgion indicas h rmoval of oil ha covrs h surfac of carbon powdr. I should b nod ha h raw marial conains almos ngligibl amoun of moisur, and i dos no mix wih war in is as-rcivd condiion. For h carbon powdr o b homognously imprgnad in ZnCl2 soluion, h layr of oil mus firs b rmovd. Th scond and hird rgions signify h rlas of volail and furhr dcomposiion of marial. Th prcursor originally conains high carbon conn; 90.9% combusibl marial and 9.1% ash. Du o is fin powdr form ha prsumably consiss of dns aromaic or graphiic srucur, longr duraion was ruird o burn h prcursor ino ash. This xplains why h wigh loss was only 25% alhough h mpraur was clos o 1000 C. Tabl 2 shows h yild and surfac ara of acivad carbons.

3 39 Muhammad Abbas Ahmad Zaini al. / Jurnal Tknologi (Scincs & Enginring) 67:2 (2014), Tabl 2 Yild and surfac ara of acivad carbons Acivad carbon Yild (%) Surfac ara (m 2 /g) ZC MC RC (a) Th yild of acivad carbon was drmind from h wigh of rsulan produc ovr h wigh of was carbon powdr afr h pr-ramn. In gnral, h acivaion of was yr powdr givs a br yild compard o ohr carbonacous marial bcaus h prcursor was radily rich in carbon conn [11]. Th valus rpord in his work wr somwha grar compard o prvious rlad works [13]. A dcras in yild indicas ha hr was burn-off of carbon marial during h acivaion. Rsuls show ha h yild of ZC is slighly highr compard o ha of RC and MC. A highr ZnCl2 raio is xpcd o inhibi h rlas of volail mar from h prcursor [14]. Th raio of rcovrd ZnCl2 usd o prpar RC is prsumably lssr han 1 du o som amoun ha has alrady bn usd up and/or vaporad from h firs acivaion, hus rsuling in a lowr yild of RZ. From Tabl 2, h valus of surfac ara wr rcordd as 288 and 104 m 2 /g for ZC and RC, rspcivly. A highr surfac ara of ZC ovr RC provd ha ZnCl2 imprgnaion raio plays an imporan rol during h acivaion, whrin is amoun drmins h surfac ara of acivad carbon. Nowihsanding ha, h uilizaion of rcovrd ZnCl2 for subsun acivaion was sill fasibl o produc acivad carbon wih high surfac ara. MC showd a lowr yild bcaus microwav haing could rach high mpraur in a shorr priod, hus spding up h rlas of ar or volail mar [15]. Th surfac ara of MC was as good as ha of RC, suggsing h ponial of using irradiad war in acivad carbon prparaion. Figur 3 shows h SEM imags of acivad carbons. Th formaion of ml, vsicls, prcipias of inorganic sals and surfac ching wr obsrvd on h surfac of acivad carbons. Undr h sam magnificaion, ZC showd a largr paricl siz compard o MC and RC du o h dominanc of acivaing agn. Comparabl morphology bwn MC and RC signifis a much lowr amoun of ZnCl2 usd o aciva RC. All acivad carbons displayd irrgular srucurs wih cracks and crvics which confirmd h amorphous and hrognous srucurs. Howvr, h por xurs ar no clarly obsrvd from hs SEM imags probably du o h fin powdr form. (b) (c) 3.2 Euilibrium Isohrms In his work, h ph of h soluion was no adjusd prior o adsorpion. A h nd of h procss, h valus of uilibrium ph wr found o b consisn for all acivad carbons sudid, and wr masurd as 6.1±0.2. Th consisn valus of uilibrium ph suggsd ha h amoun of proons adsorbd for ach acivad carbon is uniform alhough h surfac ara of acivad carbon is diffrn; ca. abou mmol/g proon was adsorbd. Thrfor, i is adua o uiliz singl componn isohrm modls o rprsn h adsorpion daa. Figur 4 displays h rmoval of MB by acivad carbons a diffrn iniial concnraions. Figur 3 SEM imags of acivad carbons (a) ZC, (b) MC and (c) RC

4 40 Muhammad Abbas Ahmad Zaini al. / Jurnal Tknologi (Scincs & Enginring) 67:2 (2014), Figur 4 Upak of mhyln blu a diffrn iniial concnraions afr 72 hours Th rmoval of MB by all acivad carbons was found o incras wih incrasing iniial concnraion. A iniial concnraion of 50 mg/l, all acivad carbons dmonsrad an idnical rmoval of MB a 25 mg/g which was uivaln o 100% rmoval. I implis h fasibiliy of using irradiad war, and rcovrd ZnCl2 for subsun acivad carbon prparaion, ha suis for adsorpion a lowr concnraion. As iniial concnraion incrass o 300 mg/l, h dcolourizaion of MB was found o follow h ordr: ZC>MC>RC, which corrsponds dircly o hir valus of surfac ara. ZC was abl o rmov narly 100% MB a concnraion approaching 200 mg/l, whil MC and RC displayd a dcrasing rnd of prcn rmoval a concnraions abov 50 mg/l. In gnral, h incras of iniial concnraion incrass h driving forc for adsorpion. A highr concnraions, howvr, h prsnc of adsorba molculs ar highr han h surfac sis can accommoda hus dcrasing h prcn rmoval. Adsorpion is a procss ha is dpndn on h iniial concnraion. Thus, if h surfac of acivad carbon is complly saurad, no chang in upak capaciy could b obsrvd vn as h concnraion incrass. This can b visualizd by h upak of RC a concnraions of 200 and 300 mg/l. Thr commonly usd isohrm modls for singl solu adsorpion, namly Langmuir [16-17], Frundlich [18] and Rdlich-Prson [19] modls wr usd o dscrib h adsorpion daa. Th Langmuir isohrm indicas monolayr adsorpion ono a complly homognous surfac, and is givn as, Q0bC 1 bc whr Q0 (mg/g) is h maximum upak pr uni mass of adsorbn o form a compl monolayr on h surfac of adsorbn, and b (L/mg) is a consan rlad o h affiniy of h binding sis. Th mpirical Frundlich isohrm basd on sorpion on a hrognous surfac is givn by, F 1 n (2) K C (3) Prson isohrm which combins h faurs of h Langmuir and Frundlich uaions can b dscribd as, AC (4) 1 BC g whr A, B and g ar all h Rdlich-Prson consans, and 0<g<1. Th Rdlich-Prson uaion bcoms Hnry s law whn g uals 0, whil i bcoms Langmuir modl whn g is uniy. Th non-linar modls wr solvd using Solvr add-in of Microsof Excl, and hir applicabiliy was dducd basd on cofficin of drminaion (R 2 ). Figur 5 shows h uilibrium adsorpion of MB ono acivad carbons, and h rspciv consans of h isohrm modls ar abulad in Tabl 3. All acivad carbons sudid displayd a concav shap upak capaciy agains uilibrium concnraion which indicas favourabl and rapid adsorpion in dilu soluion. Th valus of maximum rmoval wr rcordd as 154, 83 and 59 mg/g for ZC, MC and RC rspcivly. All hr modls wr found o corrla h adsorpion daa wll. Howvr, h Frundlich and Rdlich- Prson modls wr mor fid o linar approximaion; h R 2 valus ar clos o uniy. Th Frundlich modl suggss ha h upak of MB by acivad carbons is a normal adsorpion ono hrognous surfac. This could b suppord by h surfac morphology of acivad carbons (Figur 3). Th applicabiliy of Rdlich-Prson modl indicas h adsorpion procss as join faurs bwn Langmuir (monolayr adsorpion) and Frundlich (adsorpion on hrognous surfac) modls. As can b sn from Figur 5(a), h rmoval of MB obyd Frundlich isohrm a lowr uilibrium concnraion, and swichd o Langmuir isohrm as h upak bgan o lvl-off. Among h acivad carbons sudid, ZC dmonsrad a grar adsorpion affiniy for MB. I is likly du o is high surfac ara, which allows for grar inracion probabiliis bwn h surfac sis and adsorba molculs spcially a lowr concnraion. Tabl 3 Consans of isohrm modls Isohrm modl Acivad carbon ZC MC RC Langmuir Q 0 (mg/g) b (L/mg) R² Frundlich K F (mg/g)(l/mg) 1/n /n R² Rdlich-Prson A (L/g) B g R whr KF and 1/n, ar h Frundlich consans which corrspond o h maximum adsorpion capaciy and innsiy, rspcivly. Th 1/n valu ranging from 0 o 1 is considrd o rprsn surfac hrogniy. I is also suggsd ha h n valus ranging bwn 2 and 10 rprsn favourabl adsorpion procss. Th Rdlich-

5 41 Muhammad Abbas Ahmad Zaini al. / Jurnal Tknologi (Scincs & Enginring) 67:2 (2014), (a) whr k2 (g/mg.h) is h ra consan of psudo-scond-ordr adsorpion. Th iniial adsorpion ra, h, of psudo-scond-ordr as approaching zro is dfind as, h k (7) 2 2 Half-adsorpion im, 1/2, is dfind as h im ruird for h adsorpion o ak up half as much MB as is uilibrium valu. I is ofn usd as a masur of h adsorpion ra, and is xprssd as, k (8) 2 Figur 5 Euilibrium adsorpion of mhyln blu. (a) Lins wr prdicd from Langmuir (solid) and Frundlich (dashd) modls; (b) Lins wr prdicd from Rdlich-Prson modl 3.3 Adsorpion Kinics A br undrsanding of h mchanism and ra of adsorpion is imporan o dsign h adsorpion procss. This par dscribs h kinics valuaion of ZC a wo concnraions, i.., 50 and 300 mg/l. ZC was slcd bcaus i prforms br han h ohr wo acivad carbons, whil h wo concnraions wr chosn o valua h kinics in dilud soluion and a h poin approaching surfac sauraion. Th kinics daa was valuad by using hr kinics modls, namly psudo-firs ordr [20], Ho s psudo-scond ordr [21] and inraparicl diffusion modls [22]. Psudo-firs ordr modl is givn by, k 1 1 (5) whr (mg/g) is h amoun of MB adsorbd a im (h), and k1 (h 1 ) is h ra consan of firs ordr adsorpion. Ho s psudoscond-ordr uaion basd on chmical rlad adsorpion is xprssd as, (b) 2 k2 1 k (6) 2 Th diffusion mchanism and ra-conrolling sps in h adsorpion procss could b xplaind by h Wbr and Morris inraparicl diffusion modl [22], k 0.5 P C whr kp (mg/g.h 0.5 ) is h inraparicl diffusion ra consan, and C is h inrcp ha givs an ida abou h boundary layr hicknss, i.., h largr h inrcp, h grar h boundary layr ffc. All kinics consans wr solvd using Solvr add-in, givn h condiion whr h sum of suard rror is h las hus yild h opimum valu of corrlaion of drminaion (R 2 ). Figur 6 illusras h kinics profils of ZC a wo diffrn concnraions, and h rspciv consans ar abulad in Tabl 4. Th convx upward kinics curvs gnrally indica srong and favourabl MB adsorpion, and h uilibrium upak ovr h sudid priod was rasonably allid wih Figur 4. From Figur 6, h upak of MB was found o incras wih incrasing im upon raching a plaau a abou 30 min and 48 h for iniial concnraions of 50 and 300 mg/l, rspcivly. ZC displayd a rapid incras in adsorpion in dilud soluion during h firs fw minus, afr which h upak sars o incras gradually. Narly 100% MB rmoval (24.8 mg/g) was aaind afr 30 min h soluion was in conac wih h adsorbn. Howvr, a much slowr rmoval was obsrvd for MB concnraion of 300 mg/l. Th kinics daa wr fid o h commonly usd kinics modls o lucida h mchanisms of MB rmoval ono acivad carbon. Tabl 4 Consans of kinics modl (9) Iniial mhyln blu concnraion (mg/l) , Exp (mg/g) Psudo-firs-ordr k min h -1, Modl (mg/g) R Psudo-scond-ordr k g/mg.min g/mg.h h 42.4 g/mg.min 124 g/mg.h 1/ min h, Modl (mg/g) R Inraparicl diffusion modl k P min h -0.5 C R

6 42 Muhammad Abbas Ahmad Zaini al. / Jurnal Tknologi (Scincs & Enginring) 67:2 (2014), (a) (b) (b) Figur 7 Inraparicl diffusion modl for mhyln blu rmoval a concnraions of (a) 50 and (b) 300 mg/l Figur 6 Kinics of mhyln blu rmoval a iniial concnraions of (a) 50 and (b) 300 mg/l. Lins wr prdicd from psudo-firs-ordr (dashd) and psudo-scond-ordr (solid) modls (a) From Tabl 4, Ho s psudo-scond ordr kinics modl rprsns a rasonably br R 2 valus compard o h ohr wo kinics modls. Th calculad valus of MB upak (, Modl) wr also in agrmn wih h xprimnal valus (, Exp). MB rmoval ono ZC could hrfor b sufficinly dscribd as chmisopion or chmically drivn adsorpion [21]. Th ra consan for adsorpion in dilu soluion (50 mg/l) is mor han 500 ims grar han ha in 300 mg/l MB soluion. Also, h iniial adsorpion ra, h for dilu soluion is narly 20 ims highr. This phnomnon could b xplaind by h fac ha hr ar plny availabl sis o accommoda MB molculs a lowr concnraion which offrs fas adsorpion ra. As h concnraion incrass, mor adsorba molculs ar comping for limid numbr of availabl sis hus dcrasing h ra consan. Nowihsanding ha, a grar concnraion gradin in auous soluion aracs mor adsorba molculs o lodg on h acivad carbon surfac hus incrasing h upak capaciy; which is ru unil h surfac sauraion is rachd. Adsorpion usually follows hr conscuiv sps, i.., (i) film diffusion which ranspors h adsorba from h bulk soluion o h xrnal surfac of h adsorbn, (ii) paricl diffusion which ranspors adsorba from h liuid film o h solid surfac, and (iii) Adsorba-adsorbn inracion lading o h adsorpion. Th mchanism of adsorpion could b dscribd by h inraparicl diffusion modl [22]. Figur 7 shows h inraparicl diffusion modl for mhyln blu rmoval ono ZC, and h rspciv consans ar abulad in Tabl 4. From h plos, hr ar wo conncing lins of diffrn slops; h iniial par (sp slop) indicas h iniial sag of adsorpion ha rflcs h hicknss of boundary layr, and h scond par rprsns h ffc of inraparicl diffusion. Inraparicl diffusion is h ra-limiing sp (h slows sp in MB adsorpion ha drmins h ra consan) whn h wo lins yild a sraigh lin hrough origin whn combind. I happns whn h rsisanc in h film is almos ngligibl bcaus of hin boundary layr. Howvr, i was no h cas for ZC bcaus h adsorpion daa did no fi o h modl. Thus, h inraparicl diffusion is no h only ra-limiing sp ha is conrolling h adsorpion of MB; i is xpcd ha ohr coopraiv sps ar also involvd including film diffusion and/or chmisorpion.

7 43 Muhammad Abbas Ahmad Zaini al. / Jurnal Tknologi (Scincs & Enginring) 67:2 (2014), Tabl 5 Rmoval of mhyln blu by various adsorbns Adsorbn Maximu m upak (mg/g) ph Surfac ara (m 2 /g) Rfrnc ZnCl 2-acivad a was carbon [23] Acivad carbon fibr [24] Muli-walld carbon nanoubs [25] ZnCl 2-acivad corn husk carbon [26] rcovrd ZnCl2 and irradiad war dmonsrad fasibl mhyln blu adsorpion in dilu soluion. Dcolourizaion of mhyln blu ono acivad carbons could b dscribd by Rdlich-Prson modl, whil h kinics daa wr br fid o Ho s psudo-scond ordr modl. Acivad carbons prpard in his work could bcom a ponial candida for mhyln blu rmoval. Acknowldgmn Th auhors grafully acknowldg h suppor of Minisry of Highr Educaion Malaysia and Univrsii Tknologi Malaysia hrough UTM-Rsarch Univrsiy Gran (No. 07J58). Gypsum [27] Rfrncs Hyacinh roo powdr [28] Naural Jordanian Tripoli [29] MgO nanoparicl [30] ZnCl 2-acivad pa shlls carbon [31] Poplar lavs [32] Sugar xracd spn ric biomass [33] ZnCl 2-acivad ric husk carbon [34] ZnCl 2-acivad carbon powdr Irradiad waracivad carbon powdr Prsn sudy Prsn sudy Tabl 5 summarizs som sudis on h rmoval of MB by various adsorbns. A numbr of auhors wr siln on wo imporan paramrs ha ar usually rpord o hav influnc on h rmoval of MB, i.., surfac ara of adsorbn/acivad carbon, and h soluion ph a which h adsorpion was carrid ou. MB is a caionic dy, and hrfor a basic nvironmn is favourabl for adsorpion bcaus surfac dproonaion would arac mor MB molculs o h adsorbn. Howvr, som sudis [25-26] rpord ha soluion ph grar han 4 would no giv much diffrnc in h upak of MB. Compard o ohr adsorbns rpord in liraur, ZC and MC dmonsrad comparabl prformanc for MB rmoval a ph 5.5 (non-adjusd); which will b a mri for indusrial applicaions. 4.0 CONCLUSION Acivad carbons wr prpard using ZnCl2, rcovrd ZnCl2 and irradiad-war nvironmn for mhyln blu rmoval from auous soluion. ZnCl2-acivad carbon powdr showd a grar rmoval of mhyln blu bcaus of is highr surfac ara han h ohr wo acivad carbons. Acivad carbons prpard using [1] Environmnal Procion Agncy Profil of h Txil Indusry. Washingon: U.S. EPA. [2] Robinson, T., G. McMullan, R. Marchan, and P. Nigam Rmdiaion of Dys in Txil Efflun: A Criical Rviw on Currn Tramn Tchnologis wih a Proposd Alrnaiv. Biorsourc Tchnology. 77: [3] Forgacs, E., T. Csrhai, and G. Oros Rmoval of Synhic Dys from Waswars: A Rviw. Environmnal Inrnaional. 30: [4] Schirmr, R. H., B. Coulibaly, A. Sich, M. Schiwin, H. Mrkl, J. Eubl, K. Bckr, H. Bchr, O. Mullr, T. Zich, W. Schik, and B. Kouya Mhyln Blu as an Animalarial Agn. Rdox Rpor. 8: [5] Kupfr, A., C. Aschlimann, B. Wrmuh, and T. Crny T Prophylaxis and Rvrsal of Ifosfamid Encphalopahy wih Mhyln Blu. Lanc. 343: [6] Anjanyulu, Y., N. S. Chary, and D. S. S. Raj Dcolorisaion of Indusrial Effluns- Availabl Mhods and Emrging Tchnologis- A Rviw. Rviws Environmnal Scinc Biochnology. 4: [7] Bansal, R.C., and M. Goyal Acivad Carbon Adsorpion. Nw York: Taylor & Francis. [8] Rafaullaha, M., O. Sulaiman, R. Hashim, and A. Ahmad Adsorpion of Mhyln Blu on Low-Cos Adsorbns: A rviw. Journal of Hazardous Marials. 177: [9] Dng, H., L. Yang, G. Tao, and J. Dai Prparaion and Characrizaion of Acivad Carbon from Coon Salk by Microwav Assisd Chmical Acivaion: Applicaion in Mhyln Blu Adsorpion from Auous Soluion. Journal of Hazardous Marials. 166: [10] Marsh, H., and F. Rodriguz-Rinoso Acivad Carbon. Amsrdam: Elsvir. [11] Zaini, M. A. A., R. Okayama, and M. Machida Adsorpion of Auous Mal Ions on Cal-Manur-Compos basd Acivad Carbons. Journal of Hazardous Marials. 170: [12] Zaini, M. A. A., Y. Amano, and M. Machida Adsorpion of Havy Mals ono Acivad Carbons drivd from Polyacryloniril Fibr. Journal of Hazardous Marials. 180: [13] Mui, E. L. K., D. C. K. Ko, and G. McKay Producion of Aciv Carbons from Was Tyrs- A Rviw. Carbon. 42: [14] Qian, Q., M. Machida, and H. Tasumoo Prparaion of Acivad Carbons from Cal-Manur-Compos by Zinc Chlorid Acivaion. Biorsourc Tchnology. 98: [15] Huang, L., Y. Sun, W. Wang, Q. Yu, and T. Yang Comparaiv Sudy on Characrizaion of Acivad Carbons Prpard by Microwav and Convnional Haing Mhods and Applicaion in Rmoval of Oxyracyclin (OTC). Chmical Enginring Journal. 171: [16] Langmuir, I Th Consiuion and Fundamnal Propris of Solids and Liuids. Par I. Solid. Journal of h Amrican Chmical Sociy. 38: [17] Langmuir, I Th Adsorpion of Gass on Plan Surfacs of Glass, Mica and Plainum. Journal of h Amrican Chmical Sociy. 40: [18] Frundlich, H. M. F Abou h Adsorpion in Soluion (Ubr di Adsorpion in Losungn). Zischrif fur Physikalisch Chmi. 57A: [19] Rdlich, O., and D.vL. Prson A Usful Adsorpion Isohrm. Th Journal of Physical Chmisry. 63: 1024.

8 44 Muhammad Abbas Ahmad Zaini al. / Jurnal Tknologi (Scincs & Enginring) 67:2 (2014), [20] Lagrgrn, S Abou h Thory of So-calld Adsorpion of Solubl Subsancs (Kungliga Svnska Vnskapsakadmins). Handlingar. 24: [21] Ho, Y.S., and G. McKay A Comparison of Chmisorpion Kinics Modls Applid o Polluan Rmoval on Various Sorbns. Trans IChmE. 76B: [22] Wbr, W.J., and J.C. Morris Kinics of Adsorpion on Carbon from Soluion. Journal of h Saniary Enginring Division Amrican Sociy of Civil Enginrs. 89: [23] Sarici-Ozdmir, C Adsorpion and Dsorpion Kinics Bhaviour of Mhyln Blu ono Acivad Carbon. Physicochmical Problms of Minral Procssing. 48: [24] Ivans, M.G., T.A. Saviskaya, T.N. Nvar, and D.D. Grinshpan Adsorpiv and Srucural Characrisics of Carbon Sorbns. Inorganic Marials. 47: [25] Shahryari, Z., A.S. Goharrizi, and M. Azadi Exprimnal Sudy of Mhyln Blu Adsorpion from Auous Soluions ono Carbon Nano Tubs. Inrnaional Journal of War Rsourcs and Environmnal Enginring. 2: [26] Khodai, M., N. Ghasmi, B. Moradi, and M. Rahimi Rmoval of Mhyln Blu from Waswar by Adsorpion ono ZnCl 2 Acivad Corn Husk Carbon Euilibrium Sudis. Journal of Chmisry. In prss. [27] Rauf, M.A., I. Shhadh, A. Ahmd, and A. Al-Zamly Rmoval of Mhyln Blu from Auous Soluion by Using Gypsum as a Low Cos Adsorbn. World Acadmy of Scinc, Enginring and Tchnology. 31: [28] Soni, M., A.K.Sharma, J.K.Srivasava, and J.S. Yadav Adsorpiv Rmoval of Mhyln Blu Dy from an Auous Soluion using War Hyacinh Roo Powdr as a Low Cos Adsorbn. Inrnaional Journal of Chmical Scincs and Applicaions. 3: [29] ALzaydin, A.S Adsorpion of Mhyln Blu from Auous Soluion ono a Low-Cos Naural Jordanian Tripoli. Amrican Journal of Environmnal Scincs. 5: [30] Wanchanhuk, R., and A. Thapol Th Kinic Sudy of Mhyln Blu Adsorpion ovr MgO from PVA Tmpla Prparaion. Journal of Environmnal Scinc and Tchnology. 4: [31] Gcgl, U., G. Ozcan, and G.C. Gurpinar Rmoval of Mhyln Blu from Auous Soluion by Acivad Carbon Prpard from Pa Shlls (Pisum Saivum). Journal of Chmisry. In prss. [32] Han, X., X. Niu, and X. Ma Adsorpion Characrisics of Mhyln Blu on Poplar Laf in Bach Mod: Euilibrium, Kinics and Thrmodynamics. Koran Journal of Chmical Enginring. 29: [33] Ur-Rhman, M.S., I. Kim, and J-I. Han Adsorpion of Mhyln Blu Dy from Auous Soluion by Sugar Exracd Spn Ric Biomass. Carbohydra Polymrs. 90: [34] Sharma, Y. C., Uma, and S. N. Upadhyay An Economically Viabl Rmoval of Mhyln Blu by Adsorpion on Acivad Carbon Prpard from Ric Husk. Th Canadian Journal of Chmical Enginring. 82: