Application of Sewage Sludge as an Agricultural Soil Amendment

During the wastewater treatment process, the disposal of sewage sludge has raised many concerns about the various pollutants that are contained within it. Given the high concentrations of organic substances and nutrients found in sewage sludge, it is now attractive to apply sewage sludge as an agricultural soil amendment for growing crops and an environmentally friendly method of waste management. However, it is important to identify the properties of sewage sludge and possible challenges prior to the application. In this chapter, the physico-chemical properties of sewage sludge are described, as are the types of treatment processes and quantity and quality of sewage. Applying sewage sludge in agricultural soil was evaluated in terms of soil property and plant growth. Since sewage sludge contains pollutants, such as antibiotics, heavy metals and microplastics, the use of this sludge in agriculture may result in serious unintended environmental problems. For this reason, such issues were identified here. Lastly, conclusions are documented and possible future directions for developing agricultural applications of sewage sludge were suggested.