Abstract:Under the background of promoting environmental function quality and carbon peak and carbon neutrality, the hidden problems of repeated consumption and low sustainability in artificial nitrogen fixation/ nitrogen removal process come to prominence. Synthesizing the necessity and resource availability of ammonium-nitrogen in wastewater, research and development of ammonium-nitrogen resource recovery technology is receiving more and more attention in wastewater treatment. Among the existing techniques, electrochemical technology has become a hot research direction due to its advantages such as fast reaction, simple equipment, and convenient operation. In this paper, an overview of the research and development status of electrochemical-mediated ammonium recovery technology in recent years was reviewed. Focusing on the migration and conversion mechanism of different forms of ammonium-nitrogen in the electrochemical system, three main principles of recovery technology were introduced including electrochemical-driven migration and adsorption, cathode reaction-driven volatilization and anode reaction-driven precipitation. The enhancement effect of electrodes and membrane materials on the ammonium recovery performance was then highlighted and the energy efficiency of related processes including capacitive deionization and membrane-based processes (via cation-exchange membrane, gas-permeable membrane and bipolar membrane) was analyzed, leading to the conclusion that an integrated process toward ammonia recovery exhibits merits of low energy input and high removal/recovery efficiency. Finally, the inherent demand for technological innovation in a low-carbon background was discussed, the future efforts would hopefully be directed toward the development of high-performance system components, energy reduction, and functional expansion/smart operation to promote the high-quality and sustainable development of electrochemical-mediated ammonium recovery technology.