A review on sewage sludge (Biosolids) a resource for sustainable agriculture

Sewage sludge (Biosolids) generation is fastly increasing resulting from the regular increase of population, urban planning and industrial developments worldwide. The sludge needs to be adequately treated and environmentally managed to reduce the negative impacts of its application or disposal. The present review deals with the different applications of sewage sludge for sustainable agriculture. The scattered literature is harnessed to critically review the uses of biosolids to promote sustainable practices focusing on the productive uses of sewage sludge or biosolids. Biosolids or sewage sludge is the byproduct of municipal wastewater, sewage effluent and effluent treatment plants. The treatment plants are generating huge amount of biosolids. The present review focuses on the different applications of biosolids or sewage sludge as in many countries the biosolids or sewage sludge are frequently using for various purposes like for biogas production, land filling, organic fertilizer, soil amendment, and to enhance the crop yield of agricultural crops. Therefore, biosolids or sewage sludge is in the consideration as a resource worldwide. Besides this higher content of different heavy metals and microorganisms are the important constraints for the application of biosolids or sewage sludge in the various fields. Thus, this review emphasizes the different applications and possible limitations for the use of biosolids or sewage sludge as a resource. Efforts have been made on the possible pretreatment of biosolids or sewage sludge to make it more feasible for their applications. Therefore, different properties of biosolids or sewage sludge, their applications along with possible limitations have been discussed in the present review to formulate the biosolids or sewage sludge as a resource for the sustainable development.