Abstract:
The chromium (VI) sorption to the natural soils samples was
investigated by batch and column tests. Soil samples were previously
analyzed and characterized. The influence of physico-chemical key
parameters such as the initial concentration of chromium in solution, soil
quantity, pH and the temperature of the solution has been considered in
batch tests. The adsorption data are tested for a number of kinetic and
isotherm equations. In order to understand the adsorption mechanism, the
kinetic parameters of adsorption of chromium (VI) onto the natural soils
were determined. An evaluation of thermodynamic parameters on Cr (VI)
adsorption onto soil was made. The value of activation energy (Ea) suggests
that the rise of the solution temperature favors sorption of chromium (VI)
onto the soil, and the sorption process might be by chemical adsorption. The
results are used further to determine chromium bioavailability and the need
for soil remediation, based on risk assessment, since Cr (VI) is a powerful
epithelial irritant, and a confirmed human carcinogen.
