Adsorption of Copper, Zinc, and Nickel Using Loess as Adsorbents

Abstract

This study focuses on the investigation of the adsorption behavior of copper, zinc, and nickel on red and yellow loess by applying batch technique. Contact time, initial concentration of metal ions, and temperature were observed as the influential parameters in the adsorption process. The results expressed that the equilibrium time was attained within four hours; the adsorption capacity was temperature-dependent and endothermic. The removal efficiency at lower concentration was superior to the higher one, whereas the adsorption capacity was enhanced at higher concentrations. Freundlich and Langmuir models can be found satisfactory to predict the adsorption isotherm. The maximum adsorption capacities of red and yellow loess at 30C of Cu, Zn, and Ni were respectively found to equal 0.95 mg/g, 1.27 mg/g, 0.79 mg/g, 1.23 mg/g, 1.65 mg/g, and 1.65 mg/g. The yellow loess comprised with the highest removal capacities and the maximum adsorption capacities in comparison with the red one. Zinc consisted of the best adsorption affinity with the order of Cu<Ni<Zn for both kinds of adsorbents.