Effect of Soil Chemical and Physical Properties on Cd Mobility Studied by Soil Thin-Layer Chromatography

Heavy metals contamination threat to the environment is a big concern. Predicting the movement of heavy metals such as Cd in soil is an important goal. In this study the effect of soil chemical and physical properties on Cd mobility were done using a thin layer chromatography (Soil TLC). The soils used in this research have a wide range of organic matter (2.1-29 g/kg), pH value (4.9-8.8), CEC (4.1-99 cmol/kg), bases saturation, iron and aluminum oxides to examines its effect on Cd mobility. The (Rf) values obtained from soil thin layer chromatography ranged from 0.25 to 0.95 and it showed that Cd was slightly mobile in 64 %, moderately mobile in 29 % and very mobile in 7 % of the soils. The Rf indicates that Cd mobility would decrease with increasing amounts of iron oxide fractions; silt % and exchangeable Mg2+ in the soils. Rcd values increased with increasing amounts of the iron oxide fractions (Feo, Fep, and Fed); silt % and exchangeable Mg2+ in the soils. Finally, both Rcd and Rf factors showed Cd mobility to be higher in those soils with a high percentage of sand.