Characterization and usefulness of corn cob as biosorbent for Pb2+, Cu2+ and Zn2+ ions removal from aqueous solutions

Abstract

The objective of this study was to investigate corncob as biosorbent for heavy metals removal from aqueous solutions. All biosorption experiments were performed in batch system. The biosorbent were caracterized by thermal analysis (DTA/TGA), Scanning Electron Microscopy and Energy Disperzive X-Ray analysis (SEM-EDX) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. FTIR analysis of corn cob before and after Pb2+, Cu2+ and Zn2+ removal from aqueous solutions showed that ion exchange and chemisorption were involved in biosorption process of metal ions on to corn cob. Experimental data were fitted by Langmuir and Freundlich isotherm models. Maximum adsorption capacity of corn cob for Pb2+, Cu2+ and Zn2+ were 5,59; 2,62 i 1,23 mg/g, respectively. Desorption study showed that metal adsorbed corn cob can be effectively regenerated by HNO3 solution. Results from this study indicated that corn cob can be used as potential biosorbent for Pb2+, Cu2+ and Zn2+ removal from aqueous solutions.

Cilj ovog rada je ispitivanje mogućnosti upotrebe oklaska kukuruza za uklanjanje teških metala iz vodenih rastvora. Svi biosorpcioni eksperimenti izvođeni su u šaržnom sistemu. Karakterizacija biosorbenta izvršena je termijskom analizom (DTA/TGA), metodom skenirajuće elektronske mikro-skopije i energijsko-disperzivne rendgenske analize (SEM-EDX) i infracrvenom spektroskopijom sa Furijeovom transformacijom (FTIR). Na osnovu FTIR analize oklaska kukuruza pre i nakon uklanjanja Pb2+, Cu2+ i Zn2+ jona, ustanovljeno je da jonska izmena i hemisorpcija učestvuju u procesu biosorpcije jona metala na oklasku kukuruza. Eksperimentalni rezultati obrađeni su Lengmirovim i Frojndlihovim modelom izotermi. Maksimalni adsorpcioni kapacitet oklaska kukuruza za Pb2+, Cu2+ i Zn2+ iznosi 5,59; 2,62 i 1,23 mg/g, respektivno. Nakon ispitivanja procesa desorpcije zaključeno je da se adsorbovani joni metala na oklasku kukuruza efikasno i lako mogu ukloniti rastvorom HNO3. Rezultati ovog istraživanja ukazuju da se oklasak kukuruza može primeniti kao potencijalni biosorbent za uklanjanje Pb2+, Cu2+ i Zn2+ jona iz vodenih rastvora.