Use of sewage sludge in agricultural soils: Useful or harmful

Abstract

Sewage sludge is an important type of organic wastes among the various categories of solid waste. Organic matter resources in soils are relatively low and frequently require replenishment. Therefore, the use of sewage sludge in agricultural soils is a desirable method of their utilisation. The addition of sewage sludge to soils may be an inexpensive and effective alternative to the methods applied currently (mineral fertilisation, manure etc.). In spite of the undisputable advantages resulting from the application of sewage sludge in agriculture, it also involves some serious threats. Among those we should mention the presence of pathogens, heavy metals, and organic pollutants. In the current scenario of increasing global population, the generation of solid wastes like biosolids is bound to increase remarkably. Improper and unscientific disposal of biosolids results in several environmental issues such as surface and groundwater contamination, degradation of land, and food chain contamination. According to the principles of waste management hierarchy, agricultural recycling of biosolids will be a more environmentally preferred option over the traditional disposal methods. Utilizing the potential of biosolids to recycle valuable plant nutrients and as an effective soil amendment will not only help in sustainable management of this waste but also in minimizing the negatives associated with its traditional disposal. Every country must obey their regulations and legislations for managing their sewage sludge as a basic solution for use of sewage sludge in agricultural soil.