Heavy metal retention behavior of clayey soils

Abstract

Effective waste management requires the protection of groundwater resources against potential contamination from the leachates generated by the land disposed wastes. In general, waste disposal facilities are lined with impermeable barriers to protect against the migration of leachates into the natural water bodies. Clayey soils, due to their easy availability and economic viability, are normally preferred as liner materials. In this regard, extensive laboratory studies have been conducted on clayed soils to understand their permeability behavior as affected by the permeation of contaminant cationic solutions. It is also known that the clayey soils retain the heavy metal ions due to their surface characteristics. However, relatively little information is available on the retention characteristics of clayey soils. Hence, in this study, an attempt has been made to study the retention characteristics of clayey soils upon permeation of inorganic cationic solutions. The results indicate that the major portion of the retention of metal ions by clayed soils is through ion exchange.