Modelling the Effect of Dosage on the Biosorption of Ni 2+ Ions onto Luffa Cylindrica

Transcription

1 Journal of Marials Scincs and Applicaions 2018; 4(1): 1-9 hp:// ISSN: (Prin); ISSN: (Onlin) Modlling h Effc of Dosag on h Biosorpion of Ni 2+ Ions ono Luffa Cylindrica Innocn Osribho Oboh Dparmn of Chmical and Prolum Enginring, Univrsiy of Uyo, Uyo, Nigria addrss innocnoboh@uniuyo.du.ng Kywords Biosorpion, Luffa cylindrica, Empirical Modl, Sorpion Capaciy, Dosag Rcivd: April 30, 2017 Accpd: January 8, 2018 Publishd: January 25, 2018 Ciaion Innocn Osribho Oboh. Modlling h Effc of Dosag on h Biosorpion of Ni 2+ Ions ono Luffa Cylindrica. Journal of Marials Scincs and Applicaions. Vol. 4, No. 1, 2018, pp Absrac Nickl mal conaminaion xiss in indusrial procsss ha us nickl caalyss, such as coal gasificaion, prolum rfining, and hydrognaion of fas and oils. Thrfor, a sysmaic sudy on h rmoval of nickl from waswar is of considrabl significanc from an nvironmnal poin of viw. Luffa cylindrica, a plan marial wih wid disribuion paricularly in h ropical world, was characrizd as h surfac ara, chmical bonds, bulk dnsiy, Por siz disribuion, microsrucurs, composiion, morphology and lmnal composiion wr drmind. Biosorpion sudis wr carrid ou wih h dosag varid and h xprimnal daa obaind wr fid o som slcd kinic modls. Non-linar rgrssion mhod was usd and h rgrssd daa obaind for h various doss sudis rangd from o uniy. A kinic modl was dvlopd. This mpirical modl for prdicing h sorpion capaciy for Ni 2+ ions sorbd by Luffa cylindrica was drivd from h ra consan, quilibrium sorpion capaciy and h iniial sorpion ra. 1. Inroducion Biosorpion is an araciv chnology which involvs sorpion of dissolvd subsancs by a biomarial. I is a ponial chniqu for h rmoval of havy mals from soluions and rcovry of prcious mals [1]. I is a mabolism indpndn procss and hus can b prformd by boh living and dad clls [2]. Th spcis wih h mos oxicological rlvanc found in h indusrial ffluns ar h havy mals. Ths spcis ar bio-accumulaiv and no biodgradabl ovr im [3]. War conaminad wih mal ions can caus svral halh problms. Havy mal ions such as cadmium, zinc, nickl, chromium, coppr and lad can bio-accumula o b oxic comounds hrough h food chain [4]. Nickl is oxic and rlaivly widsprad in h nvironmn. I is usd in a wid variy of indusris such as plaing and cadmium nickl bary, phospha frilizrs, mining, pigmns, sabilizrs and alloys, and find is way o h aquaic nvironmn hrough waswar discharg [5]. Acivad carbon is h mos mployd adsorbn for havy mal rmoval from aquous soluion and hav bn wll documnd in h liraur [6-7]. Howvr, h xnsiv us of acivad carbon for mal rmoval from indusrial ffluns is xpnsiv [8], limiing is larg applicaion for waswar ramn. Thrfor, hr is a growing inrs in finding alrnaiv low-cos adsorbns for mal rmoval from aquous soluion, such as: h rsiduals of agriculural producs [9-10]. Th uiliy of hs vry low cos and nvironmnally frindly plan marials as biosorbns for h rmoval of divaln caions from aquous soluions as h cllulos,

2 2 Innocn Osribho Oboh: Modlling h Effc of Dosag on h Biosorpion of Ni 2+ Ions ono Luffa Cylindrica hmiclluloss, pcin and lignin prsn in h cll wall ar h mos imporan sorpion sis [11]. Th srucur of Luffa cylindrica for xampl, is cllulos basd [12-13], and h surfac of cllulos in conac wih war is ngaivly chargd. Nickl compound usd in his sudy will dissolv o giv h caionic mal and his will undrgo aracion on approaching h anionic Luffa cylindrica srucur [14]. On his basis, i is xpcd ha a mal caion will hav a srong sorpion affiniy for Luffa cylindrica. Howvr, som rsarchrs hav addrssd h mahmaical modlling of h sorpion of mal ions ono hs biosorbns. Earlir rpord mahmaical modls for h sorpion of havy mal ions includd: surfaccomplxaion, caion-xchang and ripl-layr modls [15]. Th purpos of his sudy is o dvlop an mpirical modl for dscribing h ffc of dosag on quilibrium sorpion of nickl (II) ions on Luffa cylindrica. 2. Marials and Mhods 2.1. Prparaion of Luffa cylindrica Th sds and spongs of L. cylindrica wr gahrd ino a clan plasic bag. Thy wr drid in h ovn a 105 C for 24 hours and afrwards ground wih a grinding mill. Th ground sds and spongs wr sivd and wr of paricl siz 0.3 o 0.6mm. This was o allow for shorr diffusion pah, rsuling in a highr ra of biosorpion [16]. Th ground sd and spong wr mixd a a raio of 1: Prparaion of Aquous Soluions Sock soluion of Nickl was prpard wih disilld war and Nickl (II) raoxosulpha (VI). All working soluions wr obaind by diluing h sock soluions wih disilld war. Th ph of h soluions was adjusd o hir rspciv opimum ph. Th concnraion of mal ions in soluions was analyzd by Aomic Absorpion Spcrophoomr. A duplica was analyzd for vry sampl o rack xprimnal rror and show capabiliy of rproducing rsuls [17] Drminaion of Opimum ph A gramm of L. cylindrica sds and spong mixur wr pu ino 250ml conical flasks conaining 50 ml of h aquous soluions ach adjusd o ph 2, 3, 4, 5, 6, 7, 7, 8, 9 and 10 for ach mal ions sudid. Thy wr agiad for 2h a 25 C. Th biosorbns wr rmovd from h aquous soluions afr biosorpion using h cnrifug a 2400 ra pr minu (rpm) for 10 minus. Th final concnraions of h mal ions rmaining wr drmind using Aomic Absorpion Spcrophoomr (AAS) Biosorpion Exprimn Th biosorpion sudis for valuaion of h Luffa cylindrica mixur for rmoval of Nickl (II) ions from aquous soluions was carrid-ou in riplica using h bach biosorpion procdur [9-10]. Th mhod of las squars was usd o prdic h kinic modl by linar rgrssion mhod. A rial and rror was usd for nonlinar rgrssion o minimiz or maximiz h objciv funcion using h solvr add-in funcion, Microsof Excl, Microsof Corporaion Drminaion of Surfac Ara Th Auosorb-1c was usd for h drminaion of h surfac ara of h ground Luffa cylindrica mixur undr sudy Drminaion of Por Siz Disribuion Th PorMasr PM-60 was usd o s h ground Luffa cylindrica mixur sampl. Th insrumn drmins boh Por volum and Por diamr of a solid or powdr by forcd inrusion of a non-wing liquid (mrcury) [18] Drminaion of h Microsrucurs, Composiion, Morphology and Elmnal Composiion of h Luffa cylindrica Mixur Th microsrucurs, composiion, and morphology of h Luffa cylindrica mixur wr analysd by mans of scanning lcron microscopy (SEM). A Philips scanning lcron microscop (ESEM XL30) quippd wih nrgy disprsiv X-ray spcromr (EDX) was usd o analys h various lmnal composiion found in h Luffa cylindrica mixur Drminaion of Chmical Bonds in Luffa cylindrica Mixur Fourir ransform infrard spcroscopy (FTIR) of h adsorbn was don by using an FTIR spcromr (Modl FTIR 2000, Shimadzu, Kyoo, Japan) [19] Drminaion of Bulk Dnsiy of Luffa cylindrica Mixur Th mhod of Okaka and Por [20] was usd in drmining h bulk dnsiy. 3. Rsuls and Discussion Tabl 1. Physical propris of h Luffa cylindrica biosorbn. Spcific surfac ara - BET (m²/g) 0.28 Toal Surfac ara (m²/g) Por Diamr Rang (µm) o Bulk dnsiy (g/cm 3 ) 0.34 Tabl 1 show h bulk dnsiy, surfac ara and por diamr rang for h biosorbn usd for his sudy. Th Spcific surfac ara using h BET mhod was 0.28m²/g and h Por diamr rang was bwn o µm. Th bulk dnsiy was 0.34g/cm 3. As obsrvd, h surfac ara for h sd and spong mixur of L. cylindrica is rlaivly low, wih por diamr valus in agrmn wih hos found for ypical msoporous marials [21].

3 Journal of Marials Scincs and Applicaions 2018; 4(1): Figur 1. SEM Scan and plo showing lmnal composiion of Luffa cylindrica. Figur 1 givs h lmnal composiion of Luffa cylindrica ha was analysd by mans of scanning lcron microscopy (SEM). Th Luffa cylindrica showd i conaind a vry high prcnag of carbon a 79.33% followd by oxygn, poassium, calcium, chlorin, phosphorus and sulphur wih wigh % valus of 12.25, 3.86, 1.58, 1.29, 0.95 and 0.75 rspcivly. Scanning lcron microscopy (SEM) of h Luffa cylindrica biosorbn was akn in ordr o vrify h prsnc of macropors in h srucur of h fibr. In h micrographs prsnd, Figur 2 shows h fibrous srucur of Luffa cylindrica, wih som fissurs and hols, which indica h prsnc macroporous srucur. Ths, should conribu a lil bi o h diffusion of h Ni (II) ions o h Luffa cylindrica biosorbn surfac [22-25]. Th small numbr of macroporous srucur is confirmd by h low spcific surfac ara of h biosorbn (s Tabl 1). As h biosorbn marial prsns fw numbrs of macroporous srucur, i adsorbd low amoun of nirogn, which ld o a low BET surfac ara [22-25]. Thrfor h major conribuion of h Ni (II) ions upak can b aribud o micro- and msoporous srucurs (s Figur 2). Figur 2. Scanning lcron microscopy of Luffa cylindrica biosorbn: Transvrsal viw of h mixur of sd and spong 4000.

4 4 Innocn Osribho Oboh: Modlling h Effc of Dosag on h Biosorpion of Ni 2+ Ions ono Luffa Cylindrica Figur 3a. FTIR spcrum of h mixur of sd and spong of L. cylindrica biosorbn bfor biosorpion. Figur 3b. FTIR spcrum of h mixur of sd and spong of L. cylindrica biosorbn afr biosorpion of Ni 2+ ions.

5 Journal of Marials Scincs and Applicaions 2018; 4(1): Figurs 3a and 3b show h FTIR spcral. Th funcional groups on h binding sis wr idnifid by FTIR spcral comparison of h fr biomass wih a viw o undrsanding h surfac binding mchanisms. Th significan bands obaind ar shown in Figur 3a and 3b. Funcional groups found in h srucur includ carboxylic, alkyns or nirils and amin groups [26]. Th srching vibraions of C-H srch of -CHO group shifd from o , , and cm -1 afr Ni 2+ ions biosorpion. Th assignd bands of h carboxylic, amin groups and alkyns or nirils vibraions also shifd on biosorpion. Th shif in h frquncy showd ha hr was biosorpion of Ni 2+ ions on h L. cylindrica biosorbn and h carboxylic and amin groups wr involvd in h sorpion of h Ni 2+ ions [11]. Figur 4. A plo showing h por siz disribuion of h biosorbn - L. cylindrical. Tabl 2. Kinic modls and paramrs for Ni (II) ions using L. cylindrica as biosorbn. Kinic paramrs Dosag Psudo-firs ordr 0.3g 0.5g 0.7g 0.9g q (mg/g) k f(min -1 ) R Psudo-Scond ordr q (mg/g) k s(g/mg/min) Kinic paramrs Dosag R Inra-paricl diffusion K i(mg/g min -0.5 ) C R Avrami q (mg/g) K a(min -1 ) n a R

6 6 Innocn Osribho Oboh: Modlling h Effc of Dosag on h Biosorpion of Ni 2+ Ions ono Luffa Cylindrica Th por siz disribuion of h Luffa cylindrica sampl was obaind by Mrcury inrusion mhod, and i is shown in Figur 4. Th disribuion of avrag por diamr curv prsns a maximum wih an avrag por diamr of abou 30 µm. Th amoun of pors sn in h Luffa cylindrica biosorbn; dcrass for avrag por diamrs ranging from 30 o 1000 µm. On h ohr hand, h amoun of avrag pors ranging from 3.0 x o 30 µm is prdominan. Thrfor, his biosorbn can b considrd mixurs of micro- and msoporous marials [22-25]. Som slcd s of kinic racion modls [27-31] wr usd o fi h xprimnal daa bu h corrlaion cofficins wr no as high as h ra law for a psudoscond ordr (Tabl 2). Th q valus found in h psudo-scond-ordr for Tabl 2 wr in good agrmn wih h xprimnal q valus. Ths rsuls indica ha h psudo-scond- ordr kinic modl should b akn ino accoun for xplaining h biosorpion procss of Ni (II) ions rmoval by h L. cylindrica biosorbn. Whn analyzing h valus of h kinic paramrs dpicd on Tabl 2, i should b mniond ha h k s valus srongly dpnd on h iniial concnraion, sinc is unis is gmg 1 min 1. Tabl 2 shows ha h kinic rsuls obaind fid vry wll o h psudo-scond-ordr kinic modl for h nickl (II) ions sudid wih R 2 valus of uniy for h various dosags undr considraion. Th sorpion of Ni (II) ions ono Luffa cylindrica could b a psudo-scond ordr procss Drivaion of Empirical Modl Luffa cylindrica conains polar funcional groups such as aldhyds, kons, and acids. Ths groups can b involvd in chmical bonding and ar rsponsibl for h caion xchang capaciy of h Luffa cylindrica [28]. I appars rasonabl ha in many cass ion xchang rahr han sorpion o fr sis is h rlvan ovrall-mchanism for h binding of mal ions in biosorpion. Sinc h ovrall charg of h biomass paricl has o b nural, any binding of on caion mus b accompanid by ihr a soichiomric rlas of ohr caions or by h binding of anions [32]. Thus, h Luffa cylindrica-mal racion may b rprsnd in wo ways: and 2L - + Ni 2+ NiL 2 2HL + Ni 2+ NiL 2 + 2H + (1a) (1b) whr L and HL ar polar sis on h Luffa cylindrica surfac. In dvloping h mahmaical dscripion of his sorpion procss, crain assumpions wr mad: a. Th procss may b psudo-scond ordr and h ra limiing sp may b chmical sorpion or chmisorpion; b. hr is a monolayr of mal ion on h surfac of Luffa cylindrica; c. h nrgy of sorpion for ach ion is h sam and indpndn of surfac covrag; d. h sorpion occurs only on localisd sis and involvs no inracions bwn sorbd ions;. h ra of sorpion is almos ngligibl in comparison wih h iniial ra of sorpion. Th ra of psudo-scond ordr racion may b dpndn on h amoun of divaln mal ion on h surfac of Luffa cylindrica and h amoun of divaln mal ion sorbd a quilibrium. Th sorpion quilibrium, q, is a funcion of, for xampl, h iniial mal ion concnraion, h Luffa cylindrica dos and h naur of solu-sorbn inracion [28]. Th ra xprssion for h sorpion dscribd by Eqs (1a) and (1b) is: or d( L) d d( HL) d = k = k [( L) ( L) ] 2 whr (L) and (HL) ar h numbr of aciv sis occupid on h Luffa cylindrica a im, (L) 0 and (HL) 0 ar h numbr of quilibrium sis availabl on h Luffa cylindrica [28]. Th kinic ra quaions can b rwrin as follows: whr k is h ra consan of sorpion, (g/mg min), q is h amoun of divaln mal ion sorbd a quilibrium, (mg/g), q is amoun of divaln mal ion on h surfac of h sorbn a anyim,, (mg/g). Sparaing h variabls in Eq. (2) givs: ingraing his for h boundary condiions = 0 o = and q = 0 o q = q, givs: his is h ingrad ra law for a psudo-scond ordr racion. Eq. (3) can b rarrangd o obain: 0 [( HL) ( HL) ] 2 dq = k d dq ( q q ) 2 ( q q ) q = 1 0 ( q q ) 2 = kd 1 = q + k ( 1/ kq 2 + / q ) 2 h =kq (2) (3) (4) (5)

7 Journal of Marials Scincs and Applicaions 2018; 4(1): Subsiuing Eq. (5) ino Eq. (4), givs: q = ( 1 / h + / q ) Alhough hr ar many facors which will influnc sorpion, conac im, ph, mpraur, sorbn concnraion, naur of h solu and is concnraion, a kinic modl is concrnd only wih h ffc of obsrvabl paramrs on h ovrall ra. Ths includ iniial mal ion concnraion, mpraur, Luffa cylindrica dos and naur of solu [28]. (6) wih an incras in h Luffa cylindrica dos from g. Th corrsponding linar plos of h valus of q, k and h agains m (dosag) wr rgrssd o obain xprssions wih xponns for hs valus in rms of h m paramrs for all h mal ions sudid Effc of Luffa cylindrica Dos and Naur of Solu Figurs 5 and 6 show ypical sorpion curvs for ffc of Luffa cylindrica dos on h sorpion kinics of zinc, nickl, coppr and lad ions ono Luffa cylindrica a mpraur of 25 C and iniial ion concnraion of 100 mg/l. Th plod xprimnal daa (Figur 5) also gav a good fi wih h psudo-scond ordr quaion and h rgrssion cofficins for h linar plos wr vry clos o 1.00 as can b sn in Tabl 3. Figur 5. Th sorbd capaciy agains im for h ffc of varid doss on h sorpion kinics of Nickl (II) ions ono Luffa cylindrica a ph= 8.0. Tabl 3. Th ffc of dosag on mal ions biosorpion daa. Dosag (g) r 2 q (mg/g) k (g/mgmin) h (mg/gmin) Figur 6 show ha for all h various doss, h amoun of h divaln mal ions sorbd incrass rapidly wih im in h bginning and vry slowly owards h nd of h racion. Furhrmor, a larg fracion of h oal amoun of mal was rmovd wihin a shor im ha is bfor 20 minus. Th plo as sn in Figur 6 also showd ha sorpion capaciy incrasd for lowr Luffa cylindrica dosags a any spcific im. Thr wr ffcs on h conac im rquird o rach sauraion du o h variaion in Luffa cylindrica doss. I was found ha h quilibrium sorpion of mal ions sudid was a funcion of Luffa cylindrica doss. Th ra consan, k, h quilibrium sorpion, q and h iniial sorpion ra, h, of sorpion a diffrn Luffa cylindrica doss wr calculad from h inrcp and slop of h sraigh lin plos of /q vrsus. Th iniial sorpion ra dcrasd Figur 6. Th sorbd capaciy agains im for h ffc of varid doss on h sorpion kinics of Nickl (II) ions ono Luffa cylindrica a ph= 8.0. Th xprssion Whr x= q, k or h Tabl 4. Empirical paramrs for prdicd q, k and h. x = Am b (7) M 2+ A q b q r 2 A k b k r 2 A h b h r 2 Ni Tabl 4 shows h mpirical paramrs for prdicd q, k and h and hir corrsponding corrlaion cofficins. Subsiuing h valus of A q, B q, A h and B h from Tabl 4 in Eq. (6), h ra law for a psudo-scond ordr racion and h rlaionship bwn q, m and can b rprsnd as: q = m m 0.96 (8)

8 8 Innocn Osribho Oboh: Modlling h Effc of Dosag on h Biosorpion of Ni 2+ Ions ono Luffa Cylindrica Figur 7. Effc of L. cylindrica dos on nickl (ii) ions sorpion a various ims. Ths quaions can hn b usd o driv h sorpion amoun of nickl a any givn dosag and h racion im. Th hr-dimnsional plo of h Equaion (8) is shown in Figur 7. Th Equaion rprsn a gnralisd prdiciv modl for h amoun of mal ion sorbd a any conac im and involvd L. cylindrica dos. I indicas ha h mal sorbd a any conac im is highr as h L. cylindrica dos is dcrasd. This is du o h fac ha incrasing h L. cylindrica dos incrass h surfac ara for sorpion and hnc h ra of mal sorpion is incrasd whn h iniial mal ion concnraion is consan. A kinic modl has bn drivd for h sorpion of h nickl (II) ions ono L. cylindrica. Th paramr which has h gras influnc on h kinics of h sorpion racion was sorpion quilibrium; q is a funcion of L. cylindrica dos and naur of solu and his is in agrmn wih prvious rsarch [28]. 4. Conclusion A kinic sudy was carrid ou and h xprimnal daa fid ino Psudo-firs ordr, Psudo-scond ordr, Inraparicl diffusion and Avrami modls using h non-linar rgrssion mhod o obain h kinic paramrs. A kinic modl has bn dvlopd and fid for h sorpion of h divaln nickl ions ono L. cylindrica. Th rsuls showd sorpion for Ni (II) ions ono L. cylindrica during agiaion by suspndd shaking; h procss can b dscribd by all kinic modls wih psudo-scond ordr having h R 2 valu of uniy for all h doss sudid. Th xprimnal daa fis h psudo-scond ordr modl basd on h assumpion ha h ra limiing sp may b chmical sorpion involving ion xchang bwn sorbn and sorba. Th paramr which has h influnc on h kinics of h sorpion racion was h sorpion quilibrium capaciy, q, a funcion of iniial mal ion concnraion, Luffa cylindrica dos and h naur of solu ion. Rfrncs [1] Vglio, F. and Bolchini, F. (1997). Rmoval of mals by biosorpion: a rviw. Hydromallurgy, 44, [2] Volsky, B. (1990). Rmoval and rcovry of havy mals by biosorpion, Biosorpion of havy mals, B. Volsky (Edior), CRC Prss, Boca Raon, FL, pp [3] Abdl-Ghani, N. T., Ahmad K. H., El-Chaghaby, G. A. and Lima, E. C. (2009). Facorial xprimnal dsign for biosorpion of iron and zinc using Typha domingnsis phyomass. Dsalinaion 249: [4] Abdlnaim, M. Y., El Shrif, I. Y., Aia, A. A., Fahy, N. A., El- Shaha. (2016). Impac of chmical acivaion on h adsorpion prformanc of common rd owards Cu(II) and Cd(II). Inrnaional Journal of Minral Procssing. 157, pp [5] Singh, S., Vrma, L. S., Sambi, S. S. and Sharma, S. K.. Adsorpion Bhaviour of Ni (II) from War ono Zoli X: Kinics and Equilibrium Sudis. Procdings of h World Congrss on Enginring and Compur Scinc 2008 (WCECS 2008), Ocobr 22-24, San Francisco, USA. [6] Luqman, C. A., Muhammad, Saidaul S. J. and Thomas S. Y. C. (2010). Modlling of Singl and Binary Adsorpions of Havy mals ono Acivad carbon- Equilibrium sudis. Pranika Journal of Scinc and Tchnology 18 (1): [7] Mohan, D., Singh, K. P. and Singh, V. K. (2005). Rmoval of hxavaln chromium from aquous soluion using low-cos acivad carbons drivd from agriculural was marials and acivad carbon fabric cloh, Ind. Eng. Chm. Rs. 44, [8] Babl, S. and Kurniawan, T. A. (2003). Low-cos adsorbns for havy mals upak from conaminad war: a rviw, J. Hazard. Mar. 97,

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