Heavy metal immobilization in the mining-contaminated soils using various industrial wastes

The remediation of contaminated sites, legacies of past industrial activities, requires more or less complex and costly measures depending on the nature and extent of contamination, the environmental protection legislation currently in force, the anticipated future use and the commercial value of the land. Remedial action involves implementing techniques capable of removing or containing the contaminants to prevent them from migrating to surrounding areas. Here we explore the possibility of using red muds, bauxite ore processing waste, and/or fly ash produced by coal fired power stations for immobilizing the heavy metals contained in severely contaminated soils. The results of laboratory column leaching demonstrate that relatively small additions of fly ash or red muds, or a combination of the two, to the contaminated soils drastically reduces the heavy metal content in the effluent.