Cadmium removal using potato peels as adsorbent: kinetic studies

Abstract

In this study, untreated waste potato peels were used as adsorbents for treatment and cadmium removal mechanisms were investigated. Maximum removal efficiency was 76% at an initial concentration of 100 mg L-1 of Cd(II) at pH 5.8 in an aqueous solutions at room temperature; 7.61 mg of cadmium was removed per gram of adsorbent. However, as the initial concentration increased, the removal efficiency decreased. Under optimum conditions, two parameters equilibrium isotherms (Langmuir, Freundlich, Temkin etc.) were applied. The Freundlich isotherm has the highest correlation (99.9%) in isotherms. Isothermal adsorption capacity (K-F) has 19.94 mg g(-1) and heterogeneity factor (1/n) 1.0 were determined. In adsorption, it was found that both the boundary layer diffusion and the intra-particle diffusion steps were effective, and the determination of the adsorption rate showed that the Type I pseudo-second-order equation had a high correlation (99%) at all concentrations.