Process for fixing pollutants, in particular heavy metals, in sewage sludges

摘要

The primary pollution load of domestic and industrial sewage sludge is demonstrated. Leaching of the pollutants from the sewage sludge is determined by elution trials. It is shown how by adding clay powder having a proportion of montmorillonite to the sewage sludge the leaching of pollutants can be substantially reduced by fixing the heavy metals, such as in particular cadmium, to clay minerals. The action of the clay minerals and in particular of the montmorillonite is explained in relation to their capacity to fix inorganic and organic compounds. In addition, a marked reduction of the odour pollution of sewage sludge during processing, transport and landfill is achieved.