Electrochemical phosphorus recovery from wastewater: a critical analysis of mechanisms, process optimization, and future pathways toward industrial application

Addressing the dual challenges of global phosphorus scarcity and aquatic eutrophication, electrochemical phosphorus recovery represents a transformative approach to achieving closed-loop phosphorus management. This work presented the first systematic comparative analysis of all mainstream electrochemical phosphorus recovery technologies: capacitive deionization (CDI), membrane capacitive deionization (MCDI), flow electrode capacitive deionization (FCDI), electrodialysis (ED), electroflocculation (EC), electrochemically mediated precipitation (EMP), and bioelectrochemical (BES). Through a critical assessment of cutting-edge advances, technology-critical design points were discussed and key system optimization principles were established. Then, the effects of initial phosphorus (P) concentration, solution pH, applied voltage and current density, and coexisting ions on the performance of electrochemical technologies for phosphorus recovery were summarized and thoroughly discussed, and the technology-specific applicability boundaries based on wastewater characteristics were clearly delineated. The analysis further determined the feasibility of various technologies for energy economy and industrial applications, while existing studies still lack a full process economic assessment of electrochemical recovery of P. Overall, this paper provides valuable guidance for technology matching based on wastewater composition, energy consumption, and recovery objectives. It establishes a roadmap for next-generation electrochemical phosphorus recovery systems, advancing both fundamental understanding and practical implementation in the circular water economy.