INFLUENCE OF SEWAGE-SLUDGE UTILIZATION AND DISPOSAL ON HEAVY-METAL MOBILITY IN SOIL - AN OVERVIEW

The utilization of different types of wastes as a source of nutrients for crop production is considered with increasing interest, particular ly in soils with a low organic matter content due intensive agricultur e practices. However, the presence of heavy metals in wastes can conta minate the food chain and lead to dangerous consequences for the healt h of men and animals. Concentration of heavy metals in wastes is very variable. A better understanding of the effect of heavy metals in soil after waste application could be achieved only from knowledge of the chemical form of these elements which determines their mobility and he nce a possible crop contamination.