Keywords: Adsorption modeling, Crystal violet, Isotherms, Kinetics, Natural adsorbent. 1. INTRODUCTION 2. MATERIALS AND METHODS

Transcription

1 Inrnaional Journal of Enhancd Rsarch in Scinc Tchnology & Enginring, ISSN: Vol. 4 Issu 6, Jun-25, pp: (55-66), Impac Facor:.252, Availabl onlin a: Bach Adsorpion Sysm of Hazardous rysal Viol ono Trad Walnu Shll: Kinic and Thrmodynamic Sudis Shamran J. Salih Dparmn of hmisry, Koya Univrsiy, KOYA Absrac: This rsarch concrn wih rmoval of (V) by adsorpion sysm ono bas-acivad walnu shll, adsorpion sudis wr achivd using bach xprimns. Th paramr sudid includs conac im, iniial dy concnraion, ph, adsorbn dos, paricl siz of adsorbn, agiaion spd and mpraur. Exprimnal rsuls showd h applicaion of boh Langmuir and Frundlich quaions. Th quilibrium of V was achivd wihin 6 min for h diffrn iniial dy concnraion ( 5 mg.l - ). ph was found o b an imporan facor in conrolling h adsorpion of caionic dy. Rmoval of V from aquous soluion was found o incras wih incras in ph, incrasing mpraur and dcras of paricl siz of h adsorbn. Th hrmodynamic funcions including (ΔG, ΔH and ΔS) for h adsorpion procss hav bn also valuad using which i was concludd ha h procss of adsorpion was sponanous and ndohrmic. Kywords: Adsorpion modling, rysal viol, Isohrms, Kinics, Naural adsorbn.. INTRODUTION A prsn, populaion growh incrass h nd for coloraion purposs such as, calico, lahr, xil, food procssing, dying, papr, cosmics and dy manufacuring indusris. This incrasd producion lad o h rlas of hazardous and oxic wass ino h nvironmn in liquid, solids or gasous form. This causs normous amosphric chang occurs. This can b dfind as an unfavorabl chang in our surrounding parly or complly du o humans aciviis dircly or indircly hrough radiaion, chmical addiion, physical addiion or addiion of micro organism. rysal viol blongs o h class of riphnylmhan dys and is usd largly as hisological sain in vrinary mdicin, as bacriosaic agn and skin disinfcan in h mdical communiy [2]. rysal viol is harmful whn ingsd or inhald and can caus lif-hraning injury o h conjunciva, skin irriaion and prmann blindnss[2,5,7]. Th harmful ffcs of V + warran i rmoval from indusrial wass prior o discharg ino war bodis and his has moivad us o ak up rsarch for is rmoval from waswar. Any subsanc which causs polluion is rmd as polluan. Thy ar dischargd from indusris, agriculur, auomobils and houshold aciviis ino h nvironmn. Laly, h word polluion was usd wih rfrnc o conaminaing of war, soil and air. Polluion mans addiion of any forign marial or any physical changs in h naural war or air which may affc h living lif. Svral mhods such as, prcipiaion, oxidaion, ozonaion, coagulaion, ion xchang, mmbran filraion, rvrs osmosis, and adsorpion hav bn proposd for h ramn of waswar conaminad wih dys [8]. In addiion, many of hs chnologis ar cos prohibiiv, spcially whn applid for raing larg was srams. Thus, adsorpion chniqus sm o hav h mos ponial for fuur us in indusrial waswar ramn, bcaus of hir provn fficincy in rmoval of organic and minral polluans and for conomic considraion. Many adsorbns hav bn usd prviously such as, acivad carbon and showd high adsorpion capaciy and good surfac raciviy. Howvr is rgnraion rsuls in 9 4% loss and dcrasd upak capaciy [6]. Ohr low cos adsorbns hav bn xploid for dy rmoval such as, orang pl, saw dus,, banana pl and papaya sds [,5,,7,2], bu hr is a nd for mor fficin, abundanly availabl and low cos co-frindly adsorbns wih high adsorpion capaciy o b usd for his purpos, and his is a prominn concrn for h rsarchr and nvironmnal chnologiss. In h prsn sudy bas modifid walnu shll ha was prpard from walnu shll (BMWS) was usd as an adsorbn for h rmoval of crysal viol 2. Adsorba : 2. MATERIALS AND METHODS rysal viol ( V), a monovaln caionic basic dy (I = 42,555, molcular formula 25 H 3 N 3 l, MW g/mol and max= 585 nm) was supplid by Mrck and usd wihou furhr purificaion. Doubl-disilld war Pag 55

2 Inrnaional Journal of Enhancd Rsarch in Scinc Tchnology & Enginring, ISSN: Vol. 4 Issu 6, Jun-25, pp: (55-66), Impac Facor:.252, Availabl onlin a: was usd for prparaion of all xprimnal soluions. A sock soluion of V mg/l was prpard in doubldisilld war. Furhr, dsird concnraions for h acual xprimns wr obaind by succssiv diluions. 2.2 Prparaion of Adsorbn: Fig.: (hmical srucur of crysal viol) Th walnu shll usd in his sudy. was obaind from pling h walnu fruis which was obaind from h local mark. Th hard xrnal pl was milld and hn sivd ino diffrn paricl sizs h fracion 25 µm d 5 µm was slcd. Th sivd pulvrizd walnu shll was washd wih doubl disilld war for dus and fin rmovals. Th prpard walnu shll was drid a5 ovr nigh, coold and sord in a dsiccaors unil rquird for us. Bas modificaion walnu shll adsorbn was prpard by mixing g marial/ ml soluion raio by raing wih NaOH (3% w/w) a room mpraur for priod h. Afr h ramns, h marial was filrd and washd wih doubl disilld war o rmov an 2.3 Drminaion of V Th concnraions of V in aquous soluions wr drmind by masuring h absorbanc of h soluion a 585 nm using a UV-visibl spcrophoomr yp (Agiln Tchnology cary sris modl UV/VIS spcrophoomr ). Aquous soluions of h dy wihin h concnraion rang (-2) mg/l wr usd for calibraion. Plo of absorbanc vrsus concnraion wr linar as shown in figur y =.2353x R² = Fig. 2: alibraion curv of V Pag 56

3 Inrnaional Journal of Enhancd Rsarch in Scinc Tchnology & Enginring, ISSN: Vol. 4 Issu 6, Jun-25, pp: (55-66), Impac Facor:.252, Availabl onlin a: Bach sudis Th fficincy of adsorbn is valuad by conducing laboraory bach mod sudis. Bach adsorpion xprimns wr carrid ou aliquos of 25 mg of adsorbn by shaking in 25 ml aquous soluion of dy of varying concnraion for diffrn im priods a naural ph (7) and mpraur ( 298 K). In addiion adsorbn dos, variaion in ph, paricl siz, agiaion spd and mpraur wr xamind. Th upak of dy adsorbd ono pin con powdr a im is q (mg g-) and was calculad using h following mass balanc rlaionship: q m V () and h prcnag (%) of rmoval was calculad as % Rmoval = Whr is h iniial dy concnraion (mg L - ), is h concnraion of dy a any im, V is h volum of soluion (L) and m is h mass of walnu shll powdr in (g). All masurmns ar, in gnral, rproducibl wihin ± %. Adsorpion isohrm Th adsorpion isohrm xprimnal daa wr fid wih wo wll-known isohrms, h Frundlich (96) and h Langmuir (98) adsorpion isohrm modls, o xplain V dy walnu shll adsorpion mchanism. Frundlich adsorpion isohrm This modl assumd a hrognous adsorpion surfac ha has unqual availabl sis wih diffrn nrgis of adsorpion. Th linarizd form of Frundlich can b wrin as Inq InK Whr q is h amoun of dy adsorbd a quilibrium im (mg g - ), is quilibrium concnraion dy in soluion (mg L-), n is h innsiy of adsorpion consan and K F is h capaciy of h adsorbns 4, 5, 2. Frundlich isohrm paramrs can b obaind from h slop and inrcp of plo bwn In q vs. In. Langmuir adsorpion isohrm F In n This modl considrs ha adsorpion aks plac a spcific homognous sis wihin h adsorbn, and i has bn usd succssfully for many adsorpion procsss of monolayr adsorpion. Th linarizd form of Langmuir isohrm modl can b xprssd as (2) (3) q (4) K q q a m m Whr q is h amoun of dy adsorbd a quilibrium im (mg g - ), is quilibrium concnraion of dy in soluion (mg L - ), q m is maximum adsorpion capaciy (mg g- ) of adsorbn and Ka is Langmuir isohrm consans (L mg - ). Ka and q m can b drmind from slop and inrcp of plo bwn /q and,7,2. Adsorpion kinics Th applicabiliy of h psudo-firs-ordr modl, psudo scond-ordr modl and inraparicl diffusion modl was invsigad o idniy h mchanism of V adsorpion on rad walnu shll as follows: Psudo-firs-ordr modl Th Lagrgrn psudo-firs-ordr modl illusrad h adsorpion kinic daa, which is h arlis known quaion Pag 57

4 Inrnaional Journal of Enhancd Rsarch in Scinc Tchnology & Enginring, ISSN: Vol. 4 Issu 6, Jun-25, pp: (55-66), Impac Facor:.252, Availabl onlin a: dscribing h adsorpion ra basd on h adsorpion capaciy. Th ingral form of h psudo-firs-ordr modl is gnrally xprssd as 7, 2. k Log ( q q ) = Log q (5) 2.33 Whr k (L min - ) and prdicd q can b drmind from h slop and inrcp of h linr plo bwn log (q -q ) and, rspcivly. Psudo-scond-ordr modl Th adsorpion kinic may b dscribd by h psudo scond-ordr modl. Th diffrnial quaion is gnrally known and dscribd as 7, 2. dq d q q 2 K (6) 2 Whr k 2 (g mg - min - ) is h scond-ordr ra consan of adsorpion. Ingraing Eq. (6) for h boundary condiions q =-q a =- is simplifid and linarizd o obain (7) 2 q k2q q Th scond-ordr ra consans wr usd o calcula h iniial adsorpion ra givn by h following quaion: h k q 2 2 Th plo of /q vrsus shows a linar rlaionship. Valus of k 2 and quilibrium adsorpion capaciy q wr calculad from h inrcp and slop of h plo of /q vrsus according o Eq. (7). Adsorpion mchanism Inraparicl diffusion modl Th adsorpion procds in svral sps involving ranspor of solu molculs from h aquous phas o h surfac of h solid paricls and hn inrior of h solid. According o Wbr and Morris (963), for mos adsorpion procsss h amoun of adsorpion varis almos proporional wih /2, which can b xprssd as (8) q K id 2 (9) Whr q is h adsorpion capaciy a im, /2 is h half lif im in scond and K id (mg g - min -/2 ) is h ra consan of h inraparicl diffusion modl. Liquid film diffusion modl In h ranspor of h adsorba molculs from h liquid phas o h solid phas, h boundary layr plays an imporan rol in adsorpion and h quaion of h liquid film diffusion modl can b wrin as q q K ln fd Whr q /q is h fracional aainmn of quilibrium, and K fd is h film diffusion ra consan. () Thrmodynamic sudy Thrmodynamic considraion of an adsorpion procss is ndd o conclud whhr h xohrmic or ndohrmic procss is naural. Th hrmodynamic paramrs, namly Gibbs fr nrgy (ΔG), nhalpy chang (ΔH) and nropy chang (ΔS) hav an imporan rol o drmin ha chang during h adsorpion procss. Assuming ha h aciviy cofficins ar uniy a low concnraions, h rlaionship of hs hrmodynamic paramrs wih adsorpion quilibrium consan K is givn by h following classical Van Hoff quaion 5,,3. Pag 58

5 Inrnaional Journal of Enhancd Rsarch in Scinc Tchnology & Enginring, ISSN: Vol. 4 Issu 6, Jun-25, pp: (55-66), Impac Facor:.252, Availabl onlin a: q K () q S H log 2.33R RT (2) G H TS (3) Whr K is h disribuion cofficin of h adsorba, and q and ar h quilibrium concnraion of V on h rad walnu shll (mg g - ) and in h soluion (mg L - ), rspcivly. R is h univrsal gas consan (8.34 J mol - K - ) and T is h mpraur in (K). ΔHand ΔS paramrs can b calculad from h slop and inrcp of h plo Log K vs. /T, rspcivly Effc of conac im Adsorbn amoun 25 mg wih dy soluion(25 ml) was kp consan for bach xprimns wih an iniial dy concnraion of 5 ppm wr prformd a narly 33K on a oscillaor a 23 rpm for, 2, 3, 4, 5, 6 and 7 minus a ph = 7. Thn opimum conac im was idnifid for furhr bach xprimnal sudy Effc of adsorbn dosag 2 mg/l of iniial dy concnraion wr usd in conjuncion wih adsorbn dos of.5,,.5, 2, 2.5 and 3 g/l. onac im (6 min), ph (7), agiaion spd (23rpm), mpraur (33K) and paricl ( 5o msh) wr kp consan Effc of iniial dy concnraion Variabl concnraion such as 5, 75,, 25, 5, 75 and 2 mg/l of iniial dy concnraion wr usd in conjuncion wih adsorbn dos of g/l. onac im (6 min), ph (7), agiaion spd (23rpm), mpraur (33K) and paricl ( 5o msh) wr kp consan Effc of ph Iniial ph of dy soluions wr adjusd o 4, 6, 8 and for mg/l concnraion. onac im (6 min), adsorbn dos (g/l), agiaion spd (23rpm), mpraur (33K) and paricl ( 5o msh) wr kp consan Effc of paricl siz Diffrn sizd paricls of 3, 3 25 and 25 2 µm (3 µm qual o 5 msh) wr usd in conjuncion wih5 mg/l dy concnraion. onac im (6 min), adsorbn dos (g/l), ph (7), agiaion spd (23rpm), mpraur (33K) and paricl ( 5o msh) wr kp consan Effc of mpraur 33K, 33K and 323K mpraurs wr usd in conjuncion wih 5 mg/l dy concnraion. onac im (6 min), adsorbn dos (g/l), ph (7), agiaion spd (23rpm) and paricl ( 5o msh) wr kp consan. 2.5 Effc of conac im Rsuls and Discussions Upak of V was rapid in firs minus and afr 6 minus amoun of dy adsorbd was almos consan. Effc of conac im on adsorpion of V is prsnd in Figurs 3. Th iniial rapid phas may also b du o h incrasd numbr of vacan sis availabl a h iniial sag. Lar on h procss bcoms rlaivly slowr and quilibrium condiions ar rachd wihin 5 o 6 minus. A his poin, h amoun of h dy dsorbing from h adsorbn is in a sa of dynamic quilibrium wih h amoun of h dy bing adsorbd ono h rad walnu shll. Th im rquird o aain his sa of quilibrium is rmd h quilibrium im, and h amoun of dy adsorbd a h quilibrium im rflcs h maximum adsorpion capaciy of h adsorbn undr hos opraing condiions. Thrfor, furhr bach xprimns wr carrid ou a 6 minus opimum conac im. Pag 59

6 % Rmoval q (mg/g) Inrnaional Journal of Enhancd Rsarch in Scinc Tchnology & Enginring, ISSN: Vol. 4 Issu 6, Jun-25, pp: (55-66), Impac Facor:.252, Availabl onlin a: Tim (min) Fig. 3: Effc of conac im on adsorpion of V 2.6 Effc of adsorbn dosag Rmoval of V was sudid by varying h adsorbn dosag. Th prcnag of adsorpion incrasd wih incras in dosag of adsorbn. Howvr, amoun of dy adsorbd pr uni mass of adsorbn dcrasd wih incrasd in adsorbn dos from.5 o3g/l. Figurs 4 and 5. As amoun of adsorbn incrass, numbr of aciv sids availabl for adsorpion also incrass hrfor % rmoval also incrass. Sinc all aciv sids may no b availabl during adsorpion du o ovrlapping bwn h aciv sids hmslvs and hus amoun adsorbd mg/g of adsorbn dcrass. Thrfor, h adsorpion of dy incrasd wih h sorbn dosag and rachd an quilibrium valu afr crain sorbn dosag (.5 o 2 g/l) for h adsorbn Dosag of TWS (g/l) Fig.4: Effc of TWS dos on % rmoval of V 3 25 q (mg/g) Dosag of TWS (g/l) Fig. 5: Effc of TWS dos on amoun adsorbd (mg/g) of V Pag 6

7 q (mg/g) % Rmoval q (mg/g) Inrnaional Journal of Enhancd Rsarch in Scinc Tchnology & Enginring, ISSN: Vol. 4 Issu 6, Jun-25, pp: (55-66), Impac Facor:.252, Availabl onlin a: Effc of iniial dy concnraion Th amoun of V adsorbd pr uni mass of adsorbn (mg/g) incrasd wih incras in V concnraion from 5 o 2 mg/l bu h adsorpion prcnag dcrasd, figurs 6 and 7. Th Iniial concnraion provids an imporan driving forc o ovrcom all mass ransfr rsisancs of h V bwn h aquous and surfac of solid phass. Thus, a highr iniial concnraion of dy will nhanc h adsorpion procss onc of V (mg/l) Fig.6: Effc of iniial dy concnraion on adsorpion of V onc of v (mg/l) Fig.7: Prcnag rmoval of V 2.8 Effc of ph ph is a ky and on of h imporan facors in conrolling h adsorpion procss, which is funcion of hydrogn and hydroxyl ions concnraions. Th ffcs of soluion ph on V adsorpion wihin TWS wr invsigad and h rsuls ar illusrad in figur 8, which shows ha h lvaion of ph lads o incras in h adsorbd mass of polluan (q ) ono TWS ph Fig.8: Effc of ph on adsorpion of V Pag 6

8 q (mg/g) % Rmoval % Rmoval Inrnaional Journal of Enhancd Rsarch in Scinc Tchnology & Enginring, ISSN: Vol. 4 Issu 6, Jun-25, pp: (55-66), Impac Facor:.252, Availabl onlin a: Whn h ph of aquous soluion incrasd from (4 o ), q incrasd from (.86 o.93) mg/g. Th rsul can b aribud o h ffc of h soluion ph on h charg of raciv group wihin TWS which, in urn maks i mor ffciv o adsorb dy in alkalin ph and incras h ionizd abl sis. In ohr word, h prsnc of H + ions comp wih h caionic dy molculs in h soluion and prfrably occupy h binding sis availabl in h sorbn paricls. As h ph of h adsorba soluion incrass numbr of H+ ions dcrass hus making h adsorpion procss mor favorabl. In h viciniy of ph valu of, opimum dy upak is obaind. Similar rsuls hav also bn rpord lswhr. 2.9 Effc of paricl siz Th ffc of paricl siz of adsorbn on h adsorpion procss was sudid by varying h paricl siz of h adsorbn and kping ohr facors as consan. Gnrally, h amoun of adsorpion incrass wih dcras in h paricl siz of h adsorbn. Adsorpion of V on hr sizd paricls of 3, 3 25 and 25 2 µm of adsorbn was sudid. Th rsuls of variaion of hs paricl sizs on dy adsorpion ar shown in figur 7. In gnral h dcras in paricl siz will show an incras in h availabl surfac ara. Thrfor, h prcnag rmoval of dy was maximum in lowr paricl siz of an adsorbn TWS siz (m) Fig.9: Effc of paricl siz on % rmoval of V dy 2. Effc of mpraur Th mpraur has a significan ffc on h procss of adsorpion. Adsorpion of V ono TWS was sudid a hr diffrn mpraurs (33 K, 33 K and 323 K) for 2 mg/l iniial concnraion of V. Th rsuls, From h figur 8, clarly indica ha dy upak incrass wih mpraur. This may b du o h fac ha incras in mpraur incrass h ra of diffusion of h adsorba molculs across h xrnal boundary layr and in h inrnal pors of h adsorbn owing o dcras in h viscosiy of h soluion [2]. Furhr, h mobiliy of adsorba molculs also incrass wih mpraur, hrby faciliaing h formaion of surfac mono layrs. hanging h mpraur will chang h quilibrium capaciy of h adsorbn for paricular adsorba Sris Sris2 (q ) ( % ) Tmp (K) Fig.: Effc of mpraur Pag 62

9 log (q-q) Inrnaional Journal of Enhancd Rsarch in Scinc Tchnology & Enginring, ISSN: Vol. 4 Issu 6, Jun-25, pp: (55-66), Impac Facor:.252, Availabl onlin a: Evaluaion of Thrmodynamic Paramrs: Thrmodynamic paramrs such as chang in fr nrgy chang (ΔG) (J/mol), nhalpy chang (ΔH) (J/mol) and nropy chang (ΔS) (J/K/mol), wr drmind using h following quaions: solid K (4) liquid Whr K o is quilibrium consan, solid is sol id phas concnraion a quilibrium (mg.l - ), liquid is liquid phas concnraion a quilibrium (mg.l - ). G RT ln (5) K G ln K (6) RT ln K S H R RT (7) A plo of ln K o vs. /T givs a sraigh lin wih slop is qual o ΔH/ R and inrcp is qual o ΔS/R. Knowing h valu of R, ΔH and ΔS can b calculad from h valu of ΔH, ΔS and ΔG can b drmind using h quaion (3). Th rsuls ar prsnd in abl. Th posiiv valus of H indica ndohrmic naur of adsorpion. Th ngaiv valus of ΔG indicad ha h adsorpion of V ono TWS is favorabl and a sponanous procss. Th posiiv valus of S indica h incrasd disordr and randomnss a h sol id soluion inrfac of V wih h adsorbn. Th incras in h capaciy of h adsorbn o rmov V a highr mpraurs was du o acivaion of h adsorbn surfac hrby nlargmn of h por siz [6,2]. Kinic modls Adsorpion mchanism and h ponial ra conrolling sps involvd in h procss of adsorpion has bn sudid using kinic modls such as psudo-firs ordr, psudo-scond ordr and inraparicl diffusion modl9. Th linar forms of hs modls ar obaind by quaion (5), (7) and (9)..5 y = -.286x R² =.992 Sris Sris2 Sris Tim (min) Fig.: Plo of psudo-firs ordr kinic modl for adsorpion of V ono TWS a diffrn iniial concnraion Pag 63

10 log q /q Inrnaional Journal of Enhancd Rsarch in Scinc Tchnology & Enginring, ISSN: Vol. 4 Issu 6, Jun-25, pp: (55-66), Impac Facor:.252, Availabl onlin a: y =.39x +.6 R² = Sris Sris2 Sris Tim (min) Fig.2: plo of psudo-scond ordr kinic modl for adsorpion of V ono TWS a diffrn iniial concnraion Whr q and q (mg/g) ar h adsorpion capaciis a quilibrium and im, rspcivly k (min - ) and k 2 (mg. g/min) ar psudo-firs and psudo-scond ordr ra consan. Psudo scond ordr modl was dvlopd basd on h assumpion ha h ra conrolling sp is chmisorpion involving valanc forc du o sharing or xchang of lcrons bwn adsorbn and adsorba molculs5. Fig. 9 prsns h plo of psudo-firs ordr kinic for adsorpion of V ono TWS a diffrn iniial concnraions. Th highr (R 2 >.99) for h psudo-scond ordr kinics (Fig.) indica h finss of his modl and i was suggsd ha chmisorpion migh b a ra conrolling sp 5. Furhrmor, h q valus calculad using psudo-scond quaion agrd wll wih h xprimnal q indicaing ha h adsorpion of V ono TWS could b wll rprsnd using h psudo-scond ordr kinic modl. Th Frundlich quaion was mployd for h adsorpion of V ono h adsorbns. Th isohrm was rp rsnd by log q log K f log (8) n Whr q is amoun of V adsorbd a quilibrium (mg/g), is h quilibrium concnraion of V in soluion (mg/l ), K f and n ar consan incorporaing facors affcing h adsorpion capaciy and innsiy of adsorpion rspcivly. Th plos of log q vs log showd good linariy (R 2 =.99 ) indicaing h adsorpion of V obys h Frundlich adsorpion isohrm, Fig y =.4x R² = log Fig.3: Frundlich isohrm plo of ffc of iniial d y concnraion on adsorpion of V Pag 64

11 /q Inrnaional Journal of Enhancd Rsarch in Scinc Tchnology & Enginring, ISSN: Vol. 4 Issu 6, Jun-25, pp: (55-66), Impac Facor:.252, Availabl onlin a: Th valus of K f and n givn in h Tabl (3). Valus of n bwn o indicas an ffciv adsorpion 9, whil highr valus of K f rprsns an asy upak of adsorba from h soluion 2. Th Langmuir isohrm was rp rsnd by h following quaion q qmb qm (9) Whr q m is monolayr adsorpion capaciy (mg/g) and b is Langmuir consan rlad o nrgy of adsorpion (/mg). A linar plos of / q vs suggs h applicabiliy of h Langmuir isohrm Figur 2 (R 2 =.996). Th valus of q m and b wr drmind from slop and inrcps of h plos, Tabl (3) y =.64x R² = (mg/l) Fig.4: Langmuir isohrm plo of ffc of iniial dy concnraion on adsorpion of V Th ssnial faurs of h Langmuir isohrm can b xprssd in rms of dimnsionlss consan sparaion facor, R L, which is dfind by h following rlaion givn by 2 R L (2) Whr o is iniial V concnraion (mg/ l). R L valus indicas favorabl adsorpion (Tabl 5). Iniial V onc. (mg/l) Tabl : Thrmodynamic paramrs for h adsorpion of V ΔG (KJ.mol - ) ΔH (KJ.mol - ) ΔS (KJ. K - mol - ) 33K 33K 323K Tabl 2: adsorpion kinic modl paramrs obaind using spcral sudy Psudo-firs ordr kinic modl K q (xp) (mg/g) q (h) (mg/g) Psudo-scond ordr kinic modl R2 K 2 q (xp) q (h) h (mg/g) (mg/g) (mg/g.min) Tabl 3: Adsorpion isohrm modl paramrs Langmuir isohrm paramr Frundlich isohrm paramr q m b R 2 K f n R R2 Pag 65

12 Inrnaional Journal of Enhancd Rsarch in Scinc Tchnology & Enginring, ISSN: Vol. 4 Issu 6, Jun-25, pp: (55-66), Impac Facor:.252, Availabl onlin a: onclusion Th rad walnu shll biomass can b usd as an ffciv alrnaiv co-frindly and low cos adsorbn for rmoval of crysal viol from is aquous soluions. Th paramrs such as conac im, ph, iniial dy concnraion, paricl siz and mpraur hav shown significan ffc on h rmoval of V. Th maximum upak of V dy by TWS occurrd a ph. Langmuir and Frundlich wr found o b bs fiing modls wih rspc o R 2 valus. Lagrgrn psudo-scond ordr modl bs fi h kinics adsorpion. Th corrlaion cofficin R 2 =.995 for scond ordr kinic adsorpion and q (xp) valus ar consisn wih q (h) showd ha psudo scond ordr kinic quaion of Lagrgrn fi wll wih whol rang of conac im. Evaluaion of hrmodynamic paramrs indicad ha h adsorpion procss favorabl, sponanous, ndohrmic and hr occurs incrasd disordr a h solid-soluion inrfac. 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