Heavy metal retention behavior of clayey soils

Effective waste management requires the protection of groundwater resources against potential contamination from the leachates generated by the land d isposed wastes. In general, waste disposal facilities are lined with imperm eable barriers to protect against the migration of leachates into the natur al water bodies. Clayey soils, due to their easy availability and economic viability, are normally preferred as liner materials. In this regard, exten sive laboratory studies have been conducted on clayey soils to understand t heir permeability behavior as affected by the permeation of contaminant cat ionic solutions. It is also known that the clayey soils retain the heavy me tal ions due to their surface characteristics. However, relatively little i nformation is available on the retention characteristics of clayey soils. H ence, in this study, an attempt has been made to study the retention charac teristics of clayey soils upon permeation of inorganic cationic solutions. The results indicate that the major portion of the retention of metal ions by clayey soils is through ion exchange.