Equilibrium and Kinetic Studies of Biosorption of Zn(II) Ions from Wastewater Using Modified Corn Cob

The objective of this study was to convert corn cob to heavy metal ion biosorbent for wastewater treatment. Corn cob was modified with phosphoric acid (PA) to help improve their natural biosorption capacity. The influence of various parameters such as initial solution concentration, initial biomass concentration and temperature on biosorption potential of agricultural waste material was studied in detail. The adsorption equilibrium data were adequately characterized by Langmuir, Freundlich and Temkin equations. The equilibrium biosorption isotherms showed that modified corn cob possess high affinity, with sorption capacities of 79.21 mg Zn(II) per 1 g biomass. Analysis indicated that pseudo-second-order kinetics controlled the adsorption rate. All results showed that corn cob is an alternative low cost biosorbent for removal of heavy metal ions from aqueous media.