Kinetic, isotherm and thermodynamic studies of the biosorption of zinc (II) from solution by maize wrapper

Abstract

2+ from solution. The optimum pH obtained was in the range pH 5 - 7, therefore pH 6 was used for other studies. The kinetic study shows that uptake of Zn 2+ increased with time and that maximum biosorption was obtained within 60 min of the process. The result obtained showed that the pseudo- first order model correlated with the experimental data better than the pseudo-second order model examined in this study. Freundlich and Langmuir isotherm models were used to analyse the experimental data of the biosorption process. The Freundlich and Langmuir equations obtained are log � = 0.643 log Ce + 1.1177 and 1/� = 0.0411/Ce + 0.009, respectively. The correlation factors are 0.9971 and 0.9889, respectively. The free energy change for the biosorption of Zn 2+ at 27oC, initial