Effects Of Heavy Metals On The Environment By Utilization Of Urban Waste Compost For Land Application: A Review

Composting is becoming a more acceptable and economical method for treating urban waste including sewage sludge, municipal solid waste, tannery waste etc., especially for cities with a high population density. However, the major disadvantage of composting these wastes is the high heavy metal contents in the end-product then it is harmful to the environment. Heavy metals are toxic to soil, plants, aquatic life, and human health if their concentration is high in the compost. Heavy metals exhibit toxic effects toward soil biota by affecting key microbial processes and decrease the number and activity of soil microorganisms. Even low concentration of heavy metals may inhibit the physiological metabolism of the plant. Uptake of heavy metals by plants and subsequent accumulation along the food chain is a potential threat to animal and human health. Contaminants in aquatic systems, including heavy metals, stimulate the production of reactive oxygen species (ROS) that can damage fishes and other aquatic organisms. Hence the compost has to be used for agriculture it should be free from heavy metals. Therefore, the present study evaluated the effects of heavy metal containing compost on soil, plants, human health, and aquatic life.