Integrated or Risk Based Soil Management as a Tool for Ecological Restoration of Brownfields

摘要

Mining and mining related activities like processing of ore and waste disposal have resulted in a serious degradation of the environment in the vicinity of mines. Often, hazardous substances like heavy metals and organic contaminants are present in levels that affect soil life, plant growth and lead to contamination of ground- and surface waters. Classical clean-up procedures including excavation of polluted soils or in-situ treatments are often not applicable due to the sheer size of the area affected. In this case, soil management aiming at the improvement of soil conditions are a key to reducing unwanted effects and restoring a natural environment. The first step of the process involves a screening of toxic substances and their behaviour in the soil - water - plant system. Based on this information suitable soil amendments can be selected that reduce the toxicity of hazardous substances. Simultaneously, plant species that are able to withstand specific toxicants are selected. The combination of soil treatment and plant growth results in an improved soil life (soil microflora and fauna like bacteria, fungi etc) which stimulates the build up of organic matter in soil. Also, contamination of ground- and surface waters is reduced as well as the loss of soil material due to erosion. Examples of successful treatments will be shown illustrating the impact of integrated soil management on soil life, plant growth and the quality of groundwater.