ABSTRACT
Increased sludge production poses a major environmental risk, and reducing the water content of sludge is the most effective strategy for reducing sewage treatment costs. However, sludge contains a large amount of hydrophilic organic compounds, resulting in poor dewatering performance. Bioleaching is a successful and cost-effective strategy for sludge dewatering. The application of bioleaching to improve sludge dewatering performance is introduced, including its principle, influencing factors, and dewatering mechanism. In addition, recent advances in bioleaching for sludge dewatering are presented. The relationship between protein secondary structure and sludge dewaterability is summarized. Additionally, the micromechanism of bioleaching to improve sludge dewatering is described from the perspective of microecology. Bioleaching technology improves the dewatering effect of sludge by changing the microstructure of extracellular polymeric substances (EPS) in sludge flocs, reducing the charge stability, and changing the microbial composition. Engineering applications of this technology can be promoted by coupling with physicochemical pre-treatment technology and enhancing the stability of microbial systems in large-scale applications.
