Sewage Sludge—A Latent Biogold

The water consumption in the country and the subsequent generation of the wastewater (domestic sewage) has increased by leaps and bounds because of the rising population and the associated activities. Sewage treatment is definitely a big challenge and adding to the complexity are the issues related to the by-product of the sewage treatment i.e., ‘Sewage Sludge’. Approximately 144 kg of dry sewage sludge is generated per million liters of sewage treated in India and accordingly around 1.4 million tons (MT) of dry sewage is generated annually. As the wastewater management infrastructure is getting increased significantly, it will result in an increased quantity of wastewater treatment which would result in an increase in the quantity of dry sewage sludge. While sewage sludge is a good source of Organic Carbon, Nitrogen, Phosphorous and Potassium which are essential for plant growth it also contains heavy metals, pathogens and microplastics which have serious health implications on human health and agricultural productivity. If these pollutants are removed from the sewage sludge, then it can be used as a soil conditioner on a mass scale. Strategies like restricting the mixing of domestic sewage with the industrial wastewater can partially address the heavy metal contamination in sewage sludge, irradiation of the sewage sludge with gamma radiation can make it pathogen free while vermi-composting can reduce the microplastics’ concentration in sewage sludge. With this background, the present research was done to discover the success stories of the effectiveness of the Sewage Sludge as an organic soil conditioner and also to bring out the associated challenges. The outcomes of the study will significantly help the policy makers to strengthen the ‘Organic Waste Management Strategy’ focusing the sewage sludge and the researchers to address the bottlenecks associated with the effective utilization of the sewage sludge. All this would help in the country’s mandate of moving towards organic farming and reduce its dependence on chemical fertilizers. It would also help in the country’s ‘Swachh Bharat Mission’ leading a path to Clean India and Green India.