Cadmium distribution coefficients and Cd transport in structured soils

摘要

In the case of cadmium transport via soil macropores, the short-term duration of an interaction between the reactive solute in aqueous phase and soil, as well as cadmium precipitation or adsorption on particles < 10(-5) m should be taken into account. Two distribution coefficients are proposed for predicting the cadmium transport in a structured soil: the matrix distribution coefficient K-dm, equal to the equilibrium distribution coefficient K-d(eq) and estimated using the conventional batch technique, and the macropore distribution coefficient K-dM, estimated using the modified batch technique. It was found that the conventional approach (using the coefficient K-d(eq) only) would underestimate a penetration of the part of Cd transported in the macropores about 255-times in the loamy-sand soil in Kalinkovo, 20-times in the loam soil in Macov, and 122-times in the clay soil in Jurova in comparison with the approach proposed in this study.