Optimizing sludge extract reuse from physico-chemical processes for zero-waste discharge: A critical review

Efficiently managing sludge extract from physio-chemical processes in water/wastewater treatment plants is imperative for achieving zero-waste discharge and advancing environmental sustainability. This review critically examines current practices, challenges, and opportunities associated with sludge extract management, with a specific focus on maximizing resource recovery while minimizing environmental impacts. It distinguishes between primary sludge, generated from physico-chemical processes, and secondary sludge from biological treatments, highlighting the unique treatment needs of primary sludge. By evaluating the role of physico-chemical processes in sludge generation and exploring the significance of zero-waste discharge strategies, this review highlights the importance of optimizing sludge extract reuse within waste management bases. Key factors influencing the quality and composition of sludge extract, including chemical characteristics and treatment techniques, are thoroughly assessed. Furthermore, technological approaches for optimizing sludge extract reuse are discussed, including advanced treatment technologies and successful case studies. Challenges and limitations associated with sludge extract reuse are identified, along with recommendations for overcoming these barriers. The implications of optimizing sludge extract reuse for environmental sustainability, resource conservation, and regulatory agreement are discussed, highlighting the potential for significant positive impacts on waste management practices. Future research directions are also delineated, aiming to advance the field of sludge extract management and promote the adoption of zero-waste strategies in waste management. This review serves as a valuable resource for sludge management guiding sustainable waste practices.