| Abstract: | Desorption of heavy metals is an important factor in determining heavy-metal availability in soils. The objective of this research was to determine the applicability of kinetic equations to describe the kinetics of copper (Cu) and cadmium (Cd) desorption at two agricultural soils of Kerman Province in Iran. For Cd and Cu desorption studies, 5 g of the air-dried <2-mm soil fraction was extracted with 25 ml of 0.01 M ethylenediamenetetraacetic acid (EDTA) at pH 7.0 with a shaker for periods of 5 to 2880 min. The desorption patterns of Cu and Cd were generally characterized by an initial fast reaction, followed by a slower continuing reaction. Desorption of Cu and Cd from the two soils was equally well described by the two-constant rate and simple Elovich equations. The results of this study can be used to make better prediction about the mobility and bioavailability of the Cu and Cd in soil. |
