Laboratory investigation of heavy metal removal by soil washing

The purpose of this study was to explore the influence of organic matter in soils while removing heavy metals by sodium metabisulfite and EDTA solutions. The results obtained show that both sodium metabisulfite and sodium EDTA solutions have good removal efficiencies of zinc and lead. However, sodium metabisulfite was effective in extracting lead from a low organic content silty clay soil, and 0.05 M EDTA solution was a better extraction agent for soils with high organic matter content. These preliminary experimental results indicate that it might be worthwhile to consider the use of a chelating agent like sodium EDTA in the treatment of heavy-metal contaminated soils.