Preparation of a starch-based degradable flocculant and its application in municipal wastewater treatment

Against the backdrop of dual carbon goals, to address environmental pollution caused by traditional hardly biodegradable flocculants like polyacrylamide (PAM), this study synthesized a starch-based bioflocculant (SDF) with both high flocculation efficiency and biodegradability. Using quaternary ammonium cationic starch and PAM as primary raw materials, SDF was synthesized via aqueous solution polymerization. Characterization results confirmed the successful synthesis of the product, demonstrating excellent thermal stability and degradability. Key findings indicate that the SDF starch backbone serves as a microbial carbon source enabling rapid degradation, while exhibiting optimal flocculation and dewatering performance under neutral conditions (pH = 7.0). Sewage sludge conditioned with SDF demonstrated higher efficiency during the dewatering stage and superior bioconversion performance in subsequent aerobic composting processes, thereby simultaneously achieving sludge reduction and resource recovery. This study provides new insights for developing integrated 'flocculation-resource recovery' green water treatment agents.