Electrochemical treatment of sewage sludge and pathogen inactivation

Abstract: Treatment and disposal of sewage sludge is still a worldwide challenging problem. Improper sludge treatment results in severe environmental impact and endangering public health. Moreover, sewage sludge disposal is a cost-intensive process. Therefore, pathogen removal and solid reduction are indispensable for sludge disposal management. In this study, a novel electrochemical method in alkaline media was developed to break down the sludge structure at room temperature. A reduction of 24.85% in total solids and 46.42% in volatile solids was achieved, which represents approximately a 25% reduction in the sludge disposal cost when compared to conventional treatment methods. Also, a 90% reduction in energy consumption was demonstrated when compared to other electrochemical methods. The post-processed samples characterization showed that a large quantity of organic material was released from the sludge samples into the liquid phase, which indicates the potential to reduce the residence time in anaerobic digesters and to generate more biogas. The proposed treatment demonstrated the feasibility of pathogen removal and biosolid production for safe landfilling or agriculture applications such as fertilizers. Graphic abstract: [Figure not available: see fulltext.]