Adsorption behavior of heavy metals on various soils

This article studies the adsorption behaviours of Cu, Ni, and Zn in various natural soils. The effects of contact time, adsorption isotherm, and temperature were investigated using the batch method. The column method was also adopted, to simulate the conditions found in the field. The results indicate that the adsorption isotherm can be satisfactorily described using the Freundlich and Langmuir models. Almost all soils showed adsorption capacities, in the order of Ni>Cu>Zn. The adsorption capacity of the metals increased when temperatures increased. From the column test, we find that heavy metals can be leached from the soil using distilled water. After leaching, the adsorption capacity of the soils slightly increased.