Department of Chemistry, Thiru Vi Ka Govt. Arts College, Thiruvarur , India. 3

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1 Scholars Journal of Enginring and Tchnology (SJET) Sch. J. Eng. Tch., 24; 2(2B): Scholars Acadmic and Scinific Publishr (An Inrnaional Publishr for Acadmic and Scinific Rsourcs) ISSN X (Onlin) ISSN (Prin) Rsarch Aricl Kinic and Thrmodynamic Sudis on h Adsorpion bhavior of Rhodamin B dy using Prosopis Juliflora Bark Carbon. M. Thilagavahi, S. Arivoli 2* and V.Vijayakumaran 3 Dparmn of Chmisry, Paukkoai Polychnic Collg, Paukkoai ,India. 2* Dparmn of Chmisry, Thiru Vi Ka Gov. Ars Collg, Thiruvarur- 6 3, India. 3 Anna univrsiy, Univrsiy collg of Enginring, Paukkoai , India. *Corrsponding auhor S. Arivoli Absrac: Th adsorpion bhavior of Rhodamin B dy from aquous soluion was invsigad using prosopis juliflora bark carbon. Th ffcs of various xprimnal facors such as conac im, adsorbn dos, iniial dy concnraion, ph and mpraur wr sudid by using h bach chniqu. Th adsorpion capaciy wr valuad by using Frundlich and Langmuir adsorpion isohrm modls. Thrmodynamic paramrs wr calculad and i was found ha h adsorpion of Rhodamin B dy using prosopis juliflora bark carbon was an xohrmic and sponanous procss. Psudo scond ordr and inraparicl diffusion modl shows good applicabiliy wih vry high corrlaion cofficin valus. Kywords: Adsorpion, Kinic, PJBC, RhoB dy, Thrmodynamic INTRODUCTION Th incras in populaion and rapid indusrial growh in India has rsuld in high dmand for dys and pigmns []. Dys ar imporan polluans in h ffluns of xil, lahr, food procssing, cosmics and papr manufacuring indusris. Th discharg of hs dy wass ino rciving srams no only affcs h ashic naur bu also rducs phoo-synhic aciviy [2]. Was wars offr considrabl rsisanc for hir biodgradaion [4] and also a svral commonly usd dys hav bn rpord o b carcinognic and muagnic for aquaic organisms [3]. Polluion causd by indusrial was war has bcom a common problm for many counris [5]. Thrfor, i is ncssary o rduc dys concnraion in h was war. Adsorpion is an araciv and alrnaiv for h ramn of was war, spcially if h adsorbn is inxpnsiv and dos no rquir an addiional prramn sp bfor is applicaion. Currnly, h mos commonly usd adsorbn is acivad carbon ha was succssfully rmov h dys from was war [6, 7]. Howvr, h acivad carbon is considrd o b an xpnsiv and problms wih rgnraion of h spn acivad carbon in is larg scal applicaion. In ordr o dcras h cos of war ramn, amps hav bn mad o find inxpnsiv low-cos adsorbns [8]. Thrfor, nw, conomical, asily availabl and highly ffciv adsorbns sill nd o b found. Th prsn sudy is usd o find ou h suiabiliy of PJBC adsorbn o rmov h Rhodamin B from aquous soluion. MATERIALS AND METHODS Adsorba Rhodamin-B (RhoB) dy usd in his sudy is purchasd from Sigma-Aldrich Company. RhoB has molcular formula C 28 H 3 N 2 Cl 3.Th dy sock soluion was prpard by dissolving accura wigh of dy in disilld war o h concnraion of g/l. Prparaion of Prosopis Juliflora Bark Carbon (PJBC) adsorbn Prosopis Juliflora Bark Carbon (PJBC) was collcd from local mark. Th collcd PJBC marials wr finly powdrd wih grinding machin. Thn h powdr was rad wih con. sulphuric acid for 2 hours, filrd and hn washd wih war. Th black produc was kp in a furnac for abou 24 hours and h mpraur was mainaind a 8 o C. Th rsuling powdr was usd for adsorpion xprimn. Bach mhod Th bach adsorpion and kinic [9] xprimns wr carrid ou by adding a fixd amoun of adsorbn (25 mg/5ml) ino a numbr of 25 ml soppr glass flasks conaining a dfini volum (5 ml in ach cas) of diffrn iniial concnraion (5,,5,2 and 25 mg/l) of dy soluions wihou changing ph and a mpraurs 3, 4, 5 and 258

2 Arivoli S al., Sch. J. Eng. Tch., 24; 2(2B): o C. Th flasks wr placd in a hrmosaic war bah shakr o nsur quilibrium was rachd. A im and a quilibrium condiion, h RhoB dy concnraion wr masurd by using spcrophoomr a 555 nm. Th amoun of adsorpion q (mg/g) a im, amoun of adsorpion a quilibrium q (mg/g), and % rmoval of RhoB dy wr calculad by (C -C )V () q O W (C -C )V (2) q O W Co -C (3) % Rmoval X Co Whr C o (mg/l), C (mg/l) and C (mg/l) ar h liquid phas concnraions of RhoB dy a iniial, a paricular im and quilibrium rspcivly.v (Lir) is h volum of h soluion. W (gram) is h mass of dry adsorbn usd. RESULT AND DISCUSSION Effc of conac im Th ffc of conac im bwn adsorbn PJBC and adsorba (RhoB) wr drmind by kping RhoB dy concnraion, adsorbn dosag, ph and mpraur wr consan. In h prsn sudy, h adsorpion procss of RhoB using PJBC was sudid for various im inrval such as,2, 3,4,5,6,7,8 and 9 minus. Th rsuls wr prsnd in Fig.. I was obsrvd ha iniially incras in im nhancs h ra of adsorpion and is quilibrium was almos aaind and 94% dy rmoval aks plac wihin 6 minus. Hrafr hr was no apprciabl changs in adsorpion. So 6 minus was h sufficin im for h maximum adsorpion of dy. Effc of PJBC adsorbn dos To sudy h ffc of PJBC dos on h RhoB adsorpion, diffrn amouns of PJBC powdr (5-5 mg) wr addd ino a 25 ml soppr glass conaining a dfini volum (5ml in ach-flask) of fixd iniial concnraion (5mg/L) of dy soluion wihou changing h ph of soluion a 3 o C as shown in Fig. 2. Th flasks wr placd in a hrmosaic war bah shakr for 6 minus and h RhoB dy concnraions wr masurd a quilibrium. From h figur, i was obsrvd ha h % rmoval incrass iniially up o 25mg/5 ml and rachs limiing valu wih fracional diffrnc. Thus adsorpion incrass wih an incras in h dos of adsorbn du o availabiliy of mor aciv sis for adsorpion. Howvr, a furhr incras in h dos of adsorbn did no affc h % rmoval of dy bcaus of h unavailabiliy of adsorba du o sauraion. So h xprimns wr carrid ou by using 25mg/5 ml of adsorbn dos. Fig. 2. Effc of adsorbn dos for h adsorpion of Rhodamin B dy [RhoB]=5 mg/l; ph=7.; Tmp=3 o C; Conac im=6 minus. Effc of soluion ph Th ffc of soluion ph for h adsorpion of RhoB using PJBC was sudid by mixing 5 mg/l of RhoB dy concnraion and 25 mg/5ml of adsorbn wih diffrn ph valus (2 o) a 3 o C as shown in figur 3. Th ph was adjusd wih.n NaOH and.n HCl soluions and ph of h soluion was masurd by ph mr. Agiaion was mad for 6 minus. Fig.. Effc of conac im for h adsorpion of Rhodamin B dy [RhoB]=5mg/L; ph=7.; Tmp=3 o C; Adsorbn dos=25mg/5ml. Th adsorpion of h dy dpnds on h soluion ph and (ph zpc ) zro poin charg of h adsorbn. Th zro poin charg of h PJBC is 4.Th adsorpion of dy was highr a a soluion ph > ph zpc. This could b du o mor ngaiv chargs a h PJBC adsorbn surfac, rsuling in h highr % rmoval of h dy occur. Bu in h ph< ph zpc h posiiv chargs 259

3 Arivoli S al., Sch. J. Eng. Tch., 24; 2(2B): on h adsorbn surfac, which may dcras h % rmoval of h dy. Th % rmoval of RhoB incrass from ph 2 o 7.5 and suddnly dcrass. Th ph rang of 2 o 4 mor hydrogn surrounding h adsorbn surfac, his may comp wih caionic dy molcul. Th ph rang of 5 o 7.5, i.., wakly acidic and nural mdium h caionic dys asily rachs adsorbn surfac. So ha mor han 9% adsorpion aks plac wih in his ph rang. Th ph abov 8, h adsorbn surfac aciv funcional group is anionic and also surroundd by anions which prvns caionic dy adsorpion. Ths anions form complx wih caionic dy, so i dcrass h % rmoval of dy. Hnc maximum adsorpion aks plac in h ph rang of 5 o 7.5. Figur 3. Effc of iniial ph for h adsorpion of Rhodamin B dy [RhoB]=5 mg/l; Tmp=3 C; Adsorbn dos=25mg/5ml; Conac im=6 minu. Effc of mpraur Th ffc of mpraur was carrid ou a four diffrn mpraurs such as 3 o C, 4 o C, 5 o C and 6 o C in a hrmosaic war bah shakr for 6 minus. Sampls wr wihdrawn a suiabl im inrval, filrd and h filra was analyzd for h rmaining dy concnraion. Tmpraur has significan ffcs on h adsorpion capaciy, hrmodynamic paramr and kinic procss dpnds on h srucur and surfac funcional groups of an adsorbn. ADSORPTION ISOTHERMS Th adsorpion isohrms shows how h adsorba molculs ar disribud bwn h adsorbn and soluion. Th Frundlich and Langmuir isohrm wr usd o masur h adsorpion capaciy of h PJBC absorbn for h rmoval of RhoB dys. Langmuir isohrm Th Langmuir [] isohrm quaion can b dscribd by C (4) C /q Q b Q m m Whr C (mg/l) is h quilibrium concnraion of h adsorba, q (mg/g) is h amoun of adsorba pr uni mass of adsorbn, Q m and b ar Langmuir consans rlad o adsorpion capaciy and ra of adsorpion rspcivly. Q m is h amoun of adsorba a compl monolayr covrag (mg/g) which givs h maximum adsorpion capaciy of h adsorbn and b (L/mg) is h langmuir isohrm consan ha rlas o h nrgy of adsorpion (or ra of adsorpion). Th linar plo of spcific adsorpion capaciy c /q agains h quilibrium concnraion (C ) (figur no givn) shows ha h adsorpion obys h langmuir modl. Th Langmuir consan Q m and b wr drmind from h slop and inrcp of h plo. Th quilibrium paramr R L [] is usd o find ou h fasibiliy of h Langmuir isohrm (5) R L bc Whr C o (mg/l) is h iniial concnraion of adsorba and b (L/mg) is langmuir isohrm consan. Th R L valu bwn < R L < is favorabl for adsorpion. Frundlich isohrm Th linar form of Frundlich isohrm [2] is rprsnd by h quaion log q (6) log K f log C n Whr q is h amoun of dys adsorbd pr uni wigh of h adsorbn, (mg/l), K f is [mg/g (mg/l) -/n ] masur of adsorpion capaciy and /n is h adsorpion Innsiy. In gnral if K f valu incrass hn adsorpion capaciy for a givn adsorba incrass. Th magniud of h xponn /n givs an indicaion of h favorabiliy of adsorpion. Th valu of n > rprsns favorabl adsorpion condiion [3] (or) h valus of /n ar lis in h rang of o confirms h favorabl condiion for adsorpion. Frundlich and Langmuir modls wr usd o fi h xprimnal daa and hir valus wr givn in h Tabl. Th R L valus a diffrn mpraur wr calculad and givn in Tabl

4 Arivoli S al., Sch. J. Eng. Tch., 24; 2(2B): Tabl. Adsorpion isohrms paramr for h adsorpion of RhoB dy Tmp. ( o C) Langmuir Paramrs Frundlich Paramrs Q m b K f n Tabl 2. Equilibrium paramr (R L ) for h adsorpion of RhoB dy (C ) Tmpraur mg 3 o C 4 o C 5 o C 6 o C From h abl and 2, I was clar ha, hir Langmuir adsorpion capaciy (Q m ) non linarly incrass wih incras in mpraur and adsorpion innsiy (b) also non linarly incrass wih incras in mpraur. Ths Q m and b valus clarly shows ha monolayr adsorpion was disurbd by h incras in mpraur. Th R L valus lis in bwn and indicas favorabl adsorpion for all h iniial concnraion and mpraur undr invsigaion. Th Frundlich isohrm paramr indicas ha h adsorpion capaciy non linarly incrass wih incras mpraur and h n valu indicas h adsorpion is a favorabl procss. Mulilayr adsorpion is disurbd abov 4 o C, bu vry small diffrnc in nrgy of adsorpion. From hs adsorpion paramr shows h Langmuir and frundlich adsorpion is physical adsorpion. Thrmodynamic ramn of h adsorpion procss Thrmodynamic paramrs such as ΔG, ΔH, ΔS wr calculad using h following rlaion as shown in Tabl.3. G RT ln K (7) H S ln K RT R (8) Whr ΔG is h fr nrgy chang of adsorpion (KJ/mol), T is h mpraur in Klvin and R is h univrsal gas consan (8.34 J mol - K - ). ΔH is h sandard ha chang of adsorpion (KJ/mol) and ΔS is sandard nropy chang (J/mol/K). Th quilibrium consan (K ) for h adsorpion s racion was drmind from h slop of h plo of ln(q /c ) agains c a diffrn mpraur and xrapolaing o zro c according o h mhod [4].Th valu of ΔH and ΔS can b obaind from h slop and inrcp of plo of lnk agains /T. Th hrmodynamic sudy of h adsorpion of RhoB using PJBC, all h fr nrgy changs ar ngaiv, his indicas h adsorpion is a sponanous procss. Th fr nrgy incrass wih incras in mpraur, his is du o incras in h aciv si on h adsorbn. All h ΔH valus ar ngaiv, his xplain adsorpion is an xohrmic procss. All h H o valus ar blow -7 KJ/mol. This indicas h adsorpion is physical adsorpion. All h ΔS valus ar posiiv, his indicas ha hr is an incras in h randomnss during h adsorpion. From h hrmodynamic aspc, h adsorpion of RhoB using PJBC is physical adsorpion. Tabl 3. Thrmodynamic paramr for h adsorpion of RhoB dy (C ) G (KJ/mol) H S mg 3 o C 4 o C 5 o C 6 o C (KJ/mol) (J/mol/K)

5 Arivoli S al., Sch. J. Eng. Tch., 24; 2(2B): Adsorpion Kinics Th kinics of RhoB dy adsorpion using PJBC wr analyzd using psudo scond ordr and inraparicl diffusion modls. Psudo scond ordr Psudo scond ordr adsorpion kinic ra quaion [5, 6] is (9) q k q 2 2 q Whr k 2 is h ra consan of psudo scond ordr adsorpion (g mg - min - ). Th q (mg/g) and q (mg/g) wr h amoun of adsorpion a im and quilibrium. Th plo of (/q ) agains () should giv a linar rlaionship from which q and k 2 can b drmind from h slop and inrcp. Inraparicl diffusion modl Th inraparicl diffusion hory proposd by [7] is 2 q () kid C Whr k id is h inraparicl diffusion ra consan (mg g - min -/2 ) and C is consan. If h ra limiing sp is inraparicl diffusion, h q of adsorbd dy (mg/g) dpnding on h squar roo of h conac im ( /2 ) should yild a sraigh lin passing hrough h origin. Th slop of h plo of q agains /2 will giv h valu of h inraparicl diffusion ra consan (k id ) and corrlaion cofficin (R 2 ). Th conformiy of h xprimnal daa wr analyzd by using h corrlaion cofficins (R 2 ) valu. A rlaivly high R 2 valu indicas ha h modl succssfully dscribs h kinics of RhoB adsorpion. Th adsorpion kinics such as psudo scond ordr and inraparicl diffusion modl wr usd o fi h xprimnal daa using linar rgrssion analysis mhod. Th paramrs of hos modls wr summarizd in Tabl.4. From h kinic daa, h psudo scond ordr corrlaion cofficin (R 2 ) valu wr almos clos o. Th q valus calculad from h psudo scond ordr modl wr vry clos o h xprimnally calculad q valu. So h adsorpion of RhoB using PJBC follows psudo scond ordr kinic modl. In h inraparicl diffusion modl corrlaion cofficin (R 2 ) valus wr also almos clos o and also giv h inrcp valu. This inrcp valu indicas ha h lins wr no passing hrough origin, hrfor som ohr adsorpion procss affc h inraparicl diffusion. This was du o h surfac adsorpion or boundary layr adsorpion. Almos all h corrlaion cofficin (R 2 ) valu wr grar han.99. So h inraparicl diffusion aks plac along wih h boundary layr ffc. Tabl 4. Adsorpion Kinic paramrs for h adsorpion of RhoB dy C Tmp Psudo scond ordr Inraparicl diffusion mg (ᵒC) q K 2-3 R 2 K id R CONCLUSIONS Th rsuls of his sudy shows ha h Prosopis Juliflora Bark Carbon can b usd for h rmoval of h dys Rhodamin B from aquous soluion. Th quilibrium daa wr fid o h Langmuir and Frundlich modls. Th hrmodynamic 262

6 Arivoli S al., Sch. J. Eng. Tch., 24; 2(2B): sudis indicas ha adsorpion procss is xohrmic and physical adsorpion. Th kinics of h adsorpion procss was h bs fi wih psudo scond ordr kinic and inraparicl diffusion modl. This adsorpion sudis shows ha Prosopis Juliflora Bark Carbon can b usd as an fficin adsorbn for h rmoval of Rhodamin B dys from aquous soluion. REFERENCES. Ngah WSW, Ariff NFM, Hanafiah MAKM; Prparaion, characrizaion and nvironmnal applicaion of crosslinkd chiosan coad bnoni for arrazin adsorpion from aquous soluions War Air Soil and Pollu., 2; 26: Namasivayam C, Radhika R, Suba S; Upak of dys by a promising locally availabl agriculural solid was: coir pih. Was Manag., 2; 2: Chn KC, Wu JY, Huang CC, Liang YM, Hwang SCJ; Dcolorizaion of azo dy using PVAimmobilizd microorganisms. J. Biochnol., 23; : Mall ID, Srivasava VC, Agarwal NK; Rmoval of Orang-G and mhyl viol dys by adsorpion ono bagass fly ash kinic sudy and quilibrium isohrm analyss. Dys Pigmns, 26; 69: Hamdaoui O; Bach sudy of liquid-phas adsorpion of mhyln blu using cdar sawdus and crushd brick. J. Hazard. Mar. 26; 35: Faria PCC, Orfao JJM, Prira MFR; Adsorpion of anionic and caionic dys on acivad carbons wih diffrn surfac chmisris. War Rs., 24; 38: Nakagawa K, Namba A, Mukai SR, Tamon H, Ariyadjwanich P, Tanhapanichakoon W; Adsorpion of phnol and raciv dy from aquous soluion on acivad carbons drivd from solid wass, War Rs., 24; 38: Sumanji, Tjindr pal singh walia, Ishu kansal; Rmoval of Rhodamin-B by Adsorpion on Walnu Shll Charcoal. J. Surfac Sci. Tchnol., 28; 24 (3-4): Hamd BH; Rmoval of caionic dy from aquous soluion using jackfrui pl as nonconvnional low-cos adsorbn. J. Hazard. Mar. 29; 62: Langmuir I; Th adsorpion of gass on plan surfacs of glass mica,and plainum. J. Am. Chm. Soc., 98; 57: McKay C, Blair HS, Gardnr JR; Adsorpion of dys on chiin.i. Equilibrium Sudis. J. Appl. Polymr Sci., 982; 27: Frundlich H;Pr dy adsorpion in losungn (adsorpion in soluion), Z. Phys. Chm., 96; 57: Hamd BH;A novl agriculural was adsorbn for h rmoval of caionic dy from aquous soluion, J. Hazard. Mar. 29; 62: Khan AA, Singh RP;Adsorpion hrmodynamics of carbofuran on Sn (IV) arsnosilica in H +, Na + and Ca 2+ forms. Colloids and Surfacs, 987; 24: Ho YS, McKay G;Th kinic of sorpion of divaln mal ions ono sphagnum moss pa, War Rs., 2; 34: Ho YS, McKay G; Sorpion of dy from aquous soluion by pa. Chm. Eng. J., 998; 7: Wbr WJ, Morris JC; Kinics of adsorpion on carbon from soluions. J.Saniary Eng. Div., 964; 9: