Adsorption Studies of Chromium(VI) and Molybdenum(VI) Through Soil Static Phase

Adsorption of chromium(VI) and molybdenum(VI) by six types of soil beds was examined using soil thin layer chromatography. The effects of decomposition of soil organic matter by 30% H2O2, cation saturation (K+, Mg2+, Ca2+ and NH4+), size of the soil particles, soil pH, sewage sludge, sample pH and surfactants (cationic, nonionic and anionic) were investigated. On the basis of differential migration, optimum conditions for the separation of Cr(VI) from Cr(III) and from Mo(VI) on soil thin layer plates were identified. The mobility (or RF value) of Cr(VI) and Mo(VI) through all soils follows the order: Cr(VI) > Mo(VI) > Cr(III). The RF values of Cr(VI) and Mo(VI) were found to depend upon the soil parameters such as soil organic matter, clay content of soil, cation exchange capacity of soil, cation saturation, size of soil particles, soil pH, sewage sludge content and the nature of surfactant (cationic, anionic or nonionic) in the mobile phase. The obtained results have been explained on the basis of adsorption behavior of Cr(III), Cr(VI) and Mo(VI) on soil colloids