Biosorption of zinc from aqueous solution by Penicillium sp immobilised in Calcium alginate

Abstract

The biosorption of Zn (II) in aqueous solution by alginate- immobilised Penicillium sp was investigated. Parameters which are responsible for optimizing sorption such as: initial pH of the solution, contact time and initial Zn (II) concentrations were varied and observed. The results were fitted into Langmuir, Freundlich and Temkin Isotherms. Optimization parameters were focused on initial solution pH, contact time and initial Zn (II) concentrations. Results were fitted to Langmuir, Freundlich and Temkin isotherms. The maximum Zn (II) biosorption of 94.29 % in aqueous solution was achieved at pH of 6.0, contact time of 120 minutes and initial Zn (II) concentration of 1 mg/L. The experimental results showed the R² values for the isotherms to be 0.7591, 0.7780 and 0.9552 respectively for the Langmuir, Freundlich and Temkin isotherms indicating that the results fitted the Temkin isotherm more than the other isotherms. The maximum biosorption capacity was 3.78 mgg^-1 while the value of n, a measure of biosorption intensity, was 1.43 Lmg^-1 showing a favorable adsorption. These results show that immobilized Penicillium sp is a good biosorbent for the removal of Zn (II) from waste water with minimal environmental impact.