Methods for increasing sludge organic matter in sewage treatment plants

Against the backdrop of global warming, countries around the world have taken action under the call of the United Nations to reform and innovate various industries with the primary goal of achieving carbon neutrality. China proposes to achieve carbon peak by 2030 and carbon neutrality by 2060. From the perspective of wastewater treatment plants, carbon neutrality can be achieved by increasing the organic matter in sludge. In this paper, four methods for increasing sludge organic matter are discussed, such as the improvement of rainwater and sewage combined flow systems, front-end screening chemical oxygen demand (COD), A/B method – A section COD concentration, and anaerobic co-digestion. The basic principles, application, and effects of these methods are compared to give some strategies for increasing the energy recovery from sewage sludge.