Sewage sludge, also referred as biosolids, is a byproduct of sewage  treatment process. Land application of sewage sludge is one of the important disposal alternatives. Characteristics of sewage sludge depend upon the quality of sewage and type of treatment process followed. Being rich in organic and inorganic plant nutrients, sewage sludge may substitute for fertilizer, but available of potential toxic metals often restricts its uses. Sludge amendment to the soil modifies its physico-chemical and biological properties. Bioavailability of metals increases in sludge amended soils at excessive rates of application for many years. Plants differ in their abilities to absorb heavy metals from sludge applied on the soil. The aim of the paper is to review the available information on various aspects of sewage sludge application on soil fertility and consequence effects on plant production to explore the possibilities of exploiting this byproduct in agriculture.

sewage sludge; disposal alternatives; heavy metals bioavailability

Presentation: oral