Clean-Up and Assessment of Metal Contaminated Soils

Heavy metal contamination of soils is still an unsolved problem although metals are associated with human life and have been used for thousands of years. Mining activities in particular have led to the spreading of large amounts of heavy metals in the environment. In many industrial processes (e.g., in the plating industry, accumulator production, chlorine-alkali-electrolysis, pesticide production), metals and their compounds are used, produced and subjected to different finishing proc­esses, and then applied in various fields of human life. When introduced into soils, heavy metal compounds are hazardous pollutants because they are not biodegrad­able, toxic at relatively low concentrations, and they may be mobilised under changing physical-chemical conditions like redox potential or pH. Soils have a limited capacity to accumulate pollutants, and if this retention capacity is ex­ceeded, the environment, (e.g. ground and surface water, plants and livestock) is likely to be at further risk.