Characterization of Sewage Sludge for Quality Assessment and Its Safe Utilization in Agriculture

Abstract

The current investigation was undertaken to explore the physico-biochemical properties of sewage sludge (SS) and its feasible application in agricultural field as an organic manure as source of nutrients with to solve the environmental concern. Sewage sludge samples were collected from sewage treatment plants (STP), Bhagwanpur, Varanasi, Uttar Pradesh, India and passed through a 2 mm sieve for further analysis of different physical, chemical and biological parameters. The treated sewage sludge consists of both major and micro nutrients along with a good amount of organic matter. Application of this sewage sludge has the ability to enhance the physical, chemical and biological properties of soil which is beneficial for plant growth and development sustainable soil environment. However, it also contains some amount of toxic heavy metals and organic pollutants that can adversely affect soil environment depending on the origin source of sewage sludge, and treatment process of sewage sludge. Furthermore, the toxic elements go through the food chain due to its uptake and accumulation by crops posing a possible threat to human health. Sewage sludge application in soil offers essential nutrients particularly for plant growth, maintains the organic carbon in soil and decreases environmental concern with economic factors that restrict landfill or incineration disposal of sewage sludge. However, a careful assessment of the characteristics of sewage sludge is required prior to its soil application to improve the soil health without causing environmental hazard. The SS analyzed in the present study had heavy metals content but was within permissible limits as resulted its suitable for soil application as source of nutrients.