HEAVY METAL REMOVAL FROM SEWAGE SLUDGES - FACTORS GOVERNING DETOXIFICATION PROCESS EFFICIENCY.

The ultimate disposal of sewage sludge is governed to a considerable degree by the level of toxic metal contamination in the sludge. In addition, potential exploitation of sewage sludge as a resource is limited by the presence of toxic metals. Present environmental considerations and future legislative trends indicate the implementation of increasingly tighter controls on the disposal of sewage sludges with high toxic metal loadings, and this has led to the development of detoxification processes for the reduction of overall toxic metal dispersal levels. These detoxification processes have in general been based on acid treatment methods. The studies described have involved an examination of process variables in toxic metal removal systems.