Biosorption of acid dyes using spent brewery grains: Characterization and modeling

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1 Inrnaional Journal of Applid Scinc and Enginring , 2: Biosorpion of acid dys using spn brwry grains: Characrizaion and modling Dr.V.Jaikumar a, *, K.Sahish Kumar b, D.Gnana Prakash b a Dparmn of Mdical Bio-Nanochnology, Chinad Univrsiy, Klambakkam Rajiv Gandhi Salai (OMR), Chnnai , INDIA b Dparmn of Chmical Enginring, SSN Collg of Enginring, Rajiv Gandhi Salai (OMR), Kalavakkam,Chnnai , INDIA Absrac: In h prsn work h brwry indusry was is akn as a low cos biosorbn for h rmoval of acid dys from h auous soluion. Biosorpion of acid dys (Acid Yllow - AY 17 and Acid Blu - AB 25) ono spn brwry grains (SBG) was invsigad. Th biosorbn marial is characrizd using scanning lcron microscopy, FT-IR spcroscopy, XRD and BET surfac ara. Th dy binding capaciy of biosorbn was shown as a funcion of iniial ph, iniial dy concnraion, biosorbn dosag, conac im and mpraur. Euilibrium upak was found o b ph dpndn and maximum upak was obsrvd a a ph of 2 for boh h dys. Colour rmoval was found o dcras wih iniial dy concnraion, mpraur and incras wih biosorbn dosag and im. Th uilibrium daa fid vry wll o Frundlich adsorpion modl. Th rsuls showd ha boh h dys upak procsss followd h scond-ordr ra xprssion. Th sudy confirms ha h spn brwry grains can b usd as biosorbn for h rmoval of acid dys from is auous soluion. Kywords: Biosorpion; Acid dys; Spn brwry grains; Isohrm; Kinics. 1. Inroducion Dys ar synhic aromaic war-solubl disprsibl organic colorans, having ponial applicaion in various indusris [1]. Txil and dying indusry ar among imporan sourcs for h coninuous polluion of h nvironmn. Th ffluns of hs indusris ar highly colourd and h disposal of hs was ino nvironmn can b xrmly dlrious. I is rpord ha hr ar ovr 100,000 commrcially availabl dys [2] and mos of hm ar difficul o dcoloriz du o hir complx aromaic molcular srucur and hy ar also sabl o ligh, war, ha and oxidizing agns. Thr ar many srucural variis of dys such as acidic, basic, raciv, azo, disprs, dirc, va and mal complx dys. All of hs dys ar harmful, whn in conac wih living issus for a long im. Th discharg of hs dy baring ffluns o h rivr sram wihou propr ramn causs svr irrparabl damag o h living bings and crops, boh auaic and rrsrial. Th mos widly usd mhods of dy rmoval from dy conaining indusrial ffluns ar cagorizd ino chmical, physical and biological. Currnly chmical and physical mhods ar usd in indusris for * Corrsponding auhor; -mail: jaikumarphd@gmail.com Accpd for Publicaion: January 28, 2010, 2010 Chaoyang Univrsiy of Tchnology, ISSN In. J. Appl. Sci. Eng., , 1 115

2 Dr.V.Jaikumar, K.Sahish Kumar and D.Gnana Prakash hir ramn of ffluns wih rsarch concnraing on bio-basd chapr and ffciv alrnaivs. In physical ramn, adsorpion chniu has gaind mor imporanc du o hir high fficincy in h rmoval of dys from ffluns and i is a procss which is conomically fasibl compard o mmbran filraion, ion xchang, irradiaion and lcro chmical mhods. Acivad carbon is h mos widly usd adsorbn for h rmoval of colour and ramn of xil ffluns bu du o is high pric i is no usd on a gra scal [3]. This has ld rsarchrs o sarch for h us of chap and fficin alrnaiv marial from various naural [4-10] and indusrial was producs or biomass [11-12]. Th indusrial wass ha ar availabl may b ihr organic or inorganic in naur. Th survy of liraur shows ha various indusrial was or biomass from various indusris such as sugar, frmnaion, frilizr, sl, pharmacuical indusris hav bn rid as biosorbn bu no much work is don using spn brwry grains a brwry indusry was as biosorbn for h rmoval of dys from auous soluions. Spn grains ar normally uilizd as cal fd in counris whr dairy farming is pracicd. In many pars of world, spn grains ar no fully uilizd du o h absnc of his aciviy. Also, du o h prosprous mark of h brwing indusry, h producion of his marial has sadily incrasd in h las yars. Fw sudis hav bn conducd on spn grains ponial as adsorbn of acid orang 7 dy [13] and havy mal rmoval cadmium and lad from auous soluions [14]. Th purpos of his sudy is o invsiga h rmoval of acid dys by spn brwry grains a chap and abundan biomass obaind from brwry indusry. 2. Exprimnal 2.1 Marials Spn Brwry Grains, obaind from Mohan brwris and disillris Limid, Chnnai, India, was suspndd in 1M sulphuric acid soluion (20g of SBG pr 100mL of acid soluion) for on hour o rmov impuriis. Thn i was filrd and h acid soluion was discardd. Th biomass was washd wih disilld war many ims unil i is complly fr from h acid and drid a 60 º C for 24 hours. Th drid biomass was ground and sivd and sord for furhr us in h xprimns. Th adsorba AY 17 dy (C.I. = 18965, Chmical formula = C 16 H 10 Cl 2 N 4 Na 2 O 7 S 2 F W = , naur = acid yllow 17) and AB 25 (C.I. = 62055, Chmical formula = C 20 H 13 N 2 NaO 5 S, F W = , naur = acid blu 25) was supplid by Sigma-Aldrich Chmicals Ld., India. Th srucur of AB 25 and AY 17 is givn in (Figur 1) and (Figur2) An accuraly wighd uaniy (1 g) ach of AY 17 and AB 25 was dissolvd in doubl disilld war sparaly o prpar sock soluion of 1000 mg/l ach. Exprimnal soluions of h dsird concnraions wr prpard by diluion wih doubl-disilld war. 2.2 Physical characrizaion Th physical propris of SBG rlaing o Brunaur-Emm-Tllr (BET) surfac ara and oal por volum wr obaind by masuring hir nirogn adsorpion isohrm a 77 K in a surfac ara and porosiy analyzr (Modl ASAP 2020 Micromriics Co., USA). Th surfac morphology of SBG is characrizd by scanning lcron microscop (SEM) (JEOL JSM Modl 6360). Th SEM imags of various magnificaions ar givn in Figur 3a, 3b and 3c. Th Figur 4 shows FT-IR of h marial rcordd on Prkin Elmr FT-IR Modl RX 1 wih KBR plls for solid sampls and XRD parns wr akn on a Rich Sifr (Modl 3000) X- ray diffracomr using Cu-K α radiaion Analyical masurmns 116 In. J. Appl. Sci. Eng., , 2

3 Biosorpion of acid dys using spn brwry grains: Characrizaion and modling Th concnraion of h dy AY 17 and AB 25 wr drmind using a UV-vis spcrophoomr (HITACHI U 2000, spcrophoomr) a a wavlngh corrsponding o h maximum absorbanc of h dy (λ max = nm and 600 nm) rspcivly. Calibraion curvs wr plod bwn absorbanc and concnraion of h dy soluion Bach xprimns Bach xprimns wr conducd using 250 ml Erlnmyr flasks o which 50 ml of dy conaining was war and biomass wr addd. Ths flasks wr agiad in an orbial shakr a a consan spd of 150 rpm o sudy h ffc of imporan paramrs lik ph, iniial dy concnraion and adsorbn dosag. Sampls wr wihdrawn a appropria im inrvals and hs sampls wr cnrifugd (Rsarch cnrifug Rmi scinific work, India) a 4000 rpm. Th suprnaan was usd for analysis of h rsidual dy concnraion. Th ffc of ph on dy rmoval was sudid ovr a ph rang of ph was adjusd by addiion of dilu auous soluions of 0.1N HCl or 0.1N NaOH. For h opimum amoun of adsorbn pr uni mass of adsorba, a 50mL dy soluion was conacd wih diffrn amouns of SBG ill uilibrium was aaind. Th kinics of adsorpion was drmind by analyzing adsorpiv upak of h dy from h auous soluion a diffrn im inrvals. Th adsorpion isohrm was found by agiaing AY 17 and AB 25 soluion of diffrn concnraions wih h known amoun of SBG ill h uilibrium was achivd. Th sudis wr prformd a room mpraur of around 303 K. Figur 1. Chmical srucur of AB 25 Figur 2. Chmical srucur of AY 17 Figur 3a. SEM imag of SBG 170x In. J. Appl. Sci. Eng., , 2 117

4 Dr.V.Jaikumar, K.Sahish Kumar and D.Gnana Prakash Figur 3b. SEM imag of SBG 500x Figur 3c. SEM imag of SBG 1000x Tabl 1. Main physical propris of spn brwry grains (SBG) S Sampl BET (m 2 /g) V (cm 3 /g) W av (A o ) BET Surfac ara Toal por volum Avrag por widh SBG Figur 4. FTIR spcra for SBG 3. Rsuls and discussion 3.1 Physical characrizaion of SBG Th daa in Tabl 1 indicas h BET surfac ara, oal por volum and avrag por widh of SBG biosorbn. Th rsuls show ha h pors of SBG ar macroporous and possss fwr adsorpion propris bu hav gra abiliy o rap suspndd solids for sparaion from liuid soluions [15]. Th xural srucur xaminaion of SBG can b obsrvd from h SEM phoographs. I could b sn ha h obsrvaion was consisn wih h rsuls from h masurmns of physical propris givn in Tabl 1. Th IR Spcrum of SBG shown in Figur 4 xhibid broad adsorpion bands in h rgion of In. J. Appl. Sci. Eng., , 2

5 Biosorpion of acid dys using spn brwry grains: Characrizaion and modling cm-1 ha rprsn boundd OH and NH groups. Th bands a 1382 cm -1 and1044 cm -1 rprsns carbona and carbohydras. CH srch could b ascribd o h band ha appard a 2924 cm -1. Th carboxyl ions giv ris o wo bands: a srong asymmrical srching band a 1635 cm -1 and a wakr symmrical band a 1449 cm -1 for h SBG. Wid angl X-ray spcra wr obaind using a Rich Sifr (Modl 3000) diffracomr wih Cu K α radiaion (λ = A 0) (θ = 3 0 ) for h ground powdr of SBG is nm Effc of ph ph is an imporan paramr affcing h biosorpion procss. Th ffc of iniial ph on h uilibrium upak is givn in (Figur 5) for ach dy a 100 mg/l iniial dy concnraion a h liuid o solid raio of 50 ml soluion / 0.5 g biosorbn for AY 17 and 50 ml soluion / 0.4 g biosorbn for AB 25 a room mpraur. Th maximum dy sorpion occurrd a ph 2 and h rmoval dcrasd hrafr for boh h dys. This may b du o high lcrosaic aracion bwn h posiivly chargd surfac of h SBG and anionic dys. Th -SO 3 group prsn in h dys plays a major rol in nhancing h dy adsorpion procss. Acid dys ar also calld as anionic dys bcaus of h ngaiv lcrical srucur of h chromophor group. As h iniial ph incrass, h numbr of ngaivly chargd sis on h biosorbn surfacs incrass and h numbr of posiivly chargd sis dcrass. A ngaiv surfac charg dos no favor h biosorpion of dy anions du o lcrosaic rpulsion [16]. In gnral, h acidic dy upaks ar much highr in acidic soluions han hos in nural and alkalin condiions [17] Effc of iniial dy concnraion Th ffc of iniial dy concnraion on h adsorpion of dy was invsigad and shown in (Figur 6). Exprimns ar carrid ou a iniial ph 2, room mpraur 303K and biosorbn dosag of 0.5g/l for AY 17 and 0.4 g/l for AB 25. I provids an imporan driving forc o ovrcom all mass ransfr rsisancs of h dy bwn h auous and solid phass, hus incrass h upak. Th rmoval yild of AY 17 and AB 25 incrasd from 90 o 94 % and 97.6 o 99.5 % rspcivly from 25 o 150 mg/l iniial dy concnraion, and hn sard o dcras from 94 o 77 % and 99.4 o 93.8 % for iniial dy concnraion of 175 o 600 mg/l. A lowr dy concnraions solu concnraions o biosorbn sis raio is highr, which caus an incras in color rmoval [18]. A highr concnraions, lowr adsorpion yild is du o h sauraion of adsorpion sis. Figur 5.Th ffc of iniial ph of dy soluion Figur 6. Effc of iniial dy concnraion In. J. Appl. Sci. Eng., , 2 119

6 Dr.V.Jaikumar, K.Sahish Kumar and D.Gnana Prakash 3.4. Effc of biosorbn dosag Th ffc of biosorbn dosag on h rmoval of AY 17 and AB 25 by SBG a Co = 100 mg/l, ph 2 and a 303K mpraur is shown in h (Figur 7). I can b sn ha h AY 17 and AB 25 rmoval incrass up o a crain limi and hn i rmains consan. Th incras in h biosorpion wih h biosorbn dosag can b aribud o grar surfac ara and h availabiliy of mor adsorpion sis [19]. A biosorbn dosag grar han 0.5 g for AY 17 and 0.4 g for AB 25 h surfac dy concnraion and h soluion dy concnraion com o uilibrium wih ach ohr. 0.4 g/l for AB 25. Th biosorpion of AY 17 and AB 25 on SBG was invsigad as a funcion of mpraur and maximum upak valu was obaind a 30 ºC as can b sn from Fig. 9. Adsorpion dcrasd wih furhr incras in mpraur du o h dcrasd surfac aciviy suggsing ha biosorpion bwn boh h dys (AY 17 and AB 25) and SBG was an xohrmic procss and h mchanism was mainly physical adsorpion [22] Effc of conac im Th ffc of conac im on adsorpion of AY 17 by SBG a Co = 100 mg/l for adsorbn dosag 0.5 g and 0.4g for AB 25, ph 2 and a room mpraur 303K is prsnd in Fig. 8. I can b obsrvd from h figur ha rapid adsorpion of dy has akn plac in h firs 10 min and, hrafr, h ra of adsorpion dcrasd gradually and rachd uilibrium in abou 40 min. around 94 % of rmoval was obaind in abou 40 min. for boh h dys. This may b du o srong araciv forcs bwn h dy molculs and h adsorbn [20]. Fas diffusion on h xrnal surfac was followd by fas por diffusion ino h inra paricl marix o aain rapid uilibrium [21]. Furhr incras in conac im showd ha hr is no significan incras in h rmoval of dys by SBG. Figur 7. Effc of biosorbn dosag Figur 8. Effc of conac im 3.6. Effc of mpraur Invsigaion of mpraur ffc on h biosorpion of acidic dys is vry imporan in h ral applicaion of biosorpion as various xil and ohr dy ffluns ar producd a rlaivly high mpraurs. Exprimns ar carrid ou a Co = 100 mg/l, iniial ph 2, and biosorbn dosag of 0.5g/l for AY 17 and Figur 9. Effc of mpraur 120 In. J. Appl. Sci. Eng., , 2

7 Biosorpion of acid dys using spn brwry grains: Characrizaion and modling 3.7. Kinic modling In ordr o invsiga h biosorpion procsss of AY 17 and AB 25 on h SBG, psudo-firs ordr and psudo-scond ordr kinic modls wr usd Psudo-firs-ordr modl Th psudo-firs-ordr uaion is givn as: [23] d / f d = k ( ) (1) a uilibrium (mg/g), k f is h sudo-firsordr ra consan (min -1 ), and is h conac im (min). Th ingraion of E. (1) wih h iniial condiion, = 0 a = 0 lads o: log( k f ) = log (2) Th valus of adsorpion ra consan (k f ) for AY 17 and AB 25 adsorpion on SBG wr drmind from h plo of log ( - ) agains (no shown hr). Ths valus ar givn in Tabl 2a and 2b. whr is h amoun of adsorba adsorbd a im (mg/g), is h adsorpion capaciy Tabl 2a. Kinic paramrs for h rmoval of AY 17 by SBG, Psudo-firs-ordr modl C o (mg/l) (mg/g) k f (1/min) R Tabl 2b. Kinic paramrs for h rmoval of AB 25 by SBG, Psudo-firs-ordr modl C o (mg/l) (mg/g) k f (1/min) R Psudo-scond-ordr modl Th psudo-scond-ordr modl is givn as: [24] d d 2 = ks ( ) (3) Whr k s is h psudo-scond-ordr ra consan (g/mg min), is h amoun of dy adsorbd a uilibrium (mg/g), and is h amoun of dy adsorbd a im (mg/g). Ingraing E. (3) for h boundary condiions = 0 o = and =0 o = givs 2 k s = 1 + k s (4) E. (4) is h ingrad ra law for a scond-ordr racion (25) and can b rarrangd o obain = k s (5) In. J. Appl. Sci. Eng., , 2 121

8 Dr.V.Jaikumar, K.Sahish Kumar and D.Gnana Prakash This has a linar form of = k + (6) s Th iniial adsorpion ra, h (mg/g min) is dfind as: 2 h = k s (7) plo (/ ) agains (Figur 10) and (Fig. 11) for AB 25 and AY 17 rspcivly. Valus of k s, s, h and corrlaion cofficin R 2 ar lisd in Tabl 3a and 3b. Th calculad corrlaion cofficins ar closr o uniy for psudo-scond-ordr kinics han ha for h psudo-firs-ordr kinic modl. Thrfor, h sorpion can b approximad mor approprialy by h psudo-scond-ordr kinic modl for h biosorpion of AY 17 and AB 25 by SBG. Th ra paramrs k s and can b dircly obaind from h inrcp and slop of h Tabl 3a. Kinic paramrs for h rmoval of AY 17 by SBG, Psudo-scond-ordr modl C o (mg/l) (mg/g) k s (g/mg min) h (mg/g min) R Tabl 3b. Kinic paramrs for h rmoval of AB 25 by SBG, Psudo-scond-ordr modl C o (mg/l) (mg/g) k s (g/mg min) h (mg/g min) R Figur 10. Psudo-scond-ordr kinic plos for h rmoval of AB 25 Figur 11. Psudo-scond-ordr kinic plos for h rmoval of AY Euilibrium modling 122 In. J. Appl. Sci. Eng., , 2

9 Biosorpion of acid dys using spn brwry grains: Characrizaion and modling Th uilibrium sorpion isohrm is fundamnally imporan in h dsign of adsorpion sysm. Euilibrium sudis in adsorpion givs h capaciy of h sorbn. Euilibrium rlaionships bwn sorbn and sorba ar dscribd by adsorpion isohrms, usually h raio bwn h uaniy sorbd and ha rmaining in h soluion a a fixd mpraur a uilibrium [25].Th Langmuir and Frundlich isohrm modls ar gnrally usd wo paramr modls for dscripion of h nonlinar uilibrium bwn biosorpion capaciy and adsorba uilibrium concnraion a a consan mpraur Langmuir isohrm Langmuir proposd a hory o dscrib h adsorpion of gas molculs ono mal surfacs. Langmuir modl of adsorpion dpnds on h assumpion ha inrmolcular forcs dcras rapidly wih disanc and consunly prdics h xisnc of monolayr covrag of h adsorba a h our surfac of h adsorbn. Th isohrm furhr assums ha adsorpion aks plac a spcific homognous sis wihin h adsorbn. I is also assumd ha onc a dy molcul occupis a si, no furhr adsorpion can ak plac a ha si. Th Langmuir isohrm is ofn usd o dscrib h sorpion of solu from soluion as bc = (8) m 1 + bc This rlaion can b wrin in linarizd form as C C = 1 + (9) bm m Whr is h amoun of adsorba adsorbd a uilibrium (mg/g), b is h Langmuir consan rlad o h nrgy of sorpion (L/mg), m is h maximum sorpion capaciy corrsponding o compl monolayr covrag (mg/g), and C is h uilibrium solu concnraion (mg/l) Frundlich isohrm Th mpirical Frundlich uaion ha corrsponds o h sorpion on hrognous surfac is givn blow: f 1/ n = K C (10) Whr K f and n ar h Frundlich consans characrisics of h sysm (n, dimnsionlss; K f, (mg 1 1/n g 1 l 1/n ). E. (10) can b linarizd in logarihmic form and h Frundlich consans can hn b drmind. Frundlich and Langmuir isohrm consans wr drmind from h plos of ln vrsus ln C and for AB 25 and AY 17 rspcivly and C / vrsus C (no shown hr) rspcivly, a 303, 313, 323 K. Th daa poorly fi o Langmuir modl suggsing h inracions wr no simpl surfac adsorpion. I was found ha h Frundlich isohrm bs rprsns h uilibrium adsorpion of AY 17 and AB 25 on SBG. Th isohrm consans and h corrlaion cofficin, R 2 wih h xprimnal daa is givn in Tabl 4a and 4b. As sn from Tabl 4, h paramr K F (Frundlich consan) rlad o h adsorpion dnsiy incrasd wih a dcras in mpraur. This was consisn wih h xprimnal obsrvaion; i also indicas ha n (innsiy of adsorpion) is grar han uniy, indicaing ha h dy is favourably adsorbd by biomass a all mpraurs sudid. 4. Conclusions Th prsn invsigaion clarly dmonsrad h applicabiliy of SBG as biosorbn for AY 17 and AB 25 dy rmoval from auous soluions. In. J. Appl. Sci. Eng., , 2 123

10 Dr.V.Jaikumar, K.Sahish Kumar and D.Gnana Prakash Tabl 4a. Frundlich isohrm consans for h biosorpion of AY 17 ono SBG a varying mpraurs T (K) K F (mg/g)(l/mg) n n R Tabl 4b. Frundlich isohrm consans for biosorpion of AB 25 ono SBG a varying mpraurs T (K) K F (mg/g)(l/mg) n n R Exprimns wr carrid ou covring a wid rang of opraing condiions. Th influnc of im, ph, adsorbn dosag, mpraur and iniial dy concnraion was criically xamind. Th soluion ph, and iniial dy concnraion playd a significan rol in affcing h capaciy of biosorbn. Th furhr incras in ph ovr 2.0 iniial dy concnraion of 150 mg/l and mpraur ovr 303 K ld o dcras in colour rmoval capaciy of h biomass. Opimum sorbn dosag was 0.5 g/l and 0.4 g/l for AY 17 and AB25 rspcivly. Th uilibrium bwn h adsorba in h soluion and on h adsorbn surfac was pracically achivd in 40 min and biosorpion kinics was found o follow psudo-scond-ordr ra xprssion for boh h dys. Euilibrium biosorpion daa wr bs rprsnd by Frundlich isohrm. Th usd biosorbn SBG can b rgnrad, sn for landfills or can b incinrad. Th prsn sudy concluds ha spn brwry grains could b mployd as a low-cos and co frindly biosorbn and as an alrnaiv o h currn xpnsiv mhods of rmoving dys from xil ffluns. Acknowldgmns Th financial suppor for his invsigaion givn by Council of Scinific and Indusrial Rsarch (CSIR), Minisry of Human Rsourcs Dvlopmn, Nw Dlhi, India undr h gran CSIR Lr. No. 9/468(371)/2007-EMR-1 dad is grafully acknowldgd. Rfrncs [ 1] Ozr, A., G. Akkaya, and M. Turabik Th biosorpion of acid rd 337 and acid blu 324 on nromorpha prolifra: Th applicaion of non linar rgrssion analysis o dy biosorpion, Chmical Enginring Journal, 112: [ 2] Zollingr, H Colour Chmisry synhsis propris and applicaions of organic dys and pigmns, Nw York: VCH publishrs, [ 3] Aksu, Z Biosorpion of raciv dys by drid acivad sludg: uilibrium and kinic modling, Biochmical ngg. Journal, 7: [ 4] McKay, G., S.J. Alln, I.F. McConvy, and M.S. Orburn Transpor procsss in h sorpion of colord ions by pa paricls, Journal of Colloid and Inrfac Scinc, 80: [ 5] McKay, G., H.S. Blair, and J.S. Gardnr Ra sudis for h adsorpion of dysuffs on chiin, Journal of Colloid and Inrfac Scinc, 95: [ 6] Asfour, H.M., O.A. Fadli, M.M. Nassr, 124 In. J. Appl. Sci. Eng., , 2

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