AOPs–Anammox Coupled System for High-Salinity High-Ammonia Organic Wastewater (HSAOW) Treatment: A Review

High-salinity high-ammonia organic wastewater (HSAOW) has diverse sources and complex compositions, and a single technology can hardly achieve efficient nitrogen removal, organic mineralization and low carbon emissions simultaneously. This paper systematically reviews the research progress of the coupled system combining advanced oxidation processes (AOPs) and anaerobic ammonium oxidation (Anammox) for the treatment of HSAOW. AOPs can degrade recalcitrant organic compounds, reduce toxicity and improve biodegradability, while the Anammox process enables low-carbon nitrogen removal via autotrophic metabolism, forming a synergistic mode of oxidative pretreatment—autotrophic nitrogen removal. For AOPs, high salinity causes radical quenching, formation of halogenated byproducts, and deactivation of electrodes and catalysts, while non-radical and electrochemical AOPs exhibit superior salt tolerance. High salinity exerts a general effect on the Anammox process, tending to promote it under low salinity, reversible inhibition under moderate salinity, and irreversible collapse under high salinity. Salt-tolerant genera such as marine Ca. Scalindua can adapt to elevated salinity through osmotic regulation. The coupled system requires synergistic regulation through process parameter optimization, configuration innovation and exogenous enhancement. Besides, the coupled system can efficiently remove conventional as well as emerging contaminants and significantly reduce carbon emissions. Moreover, water reuse can be realized via membrane integration, and simultaneous recovery of nitrogen and phosphorus can be achieved through struvite crystallization. Integrated research on interfacial interactions, salt-tolerant functional materials and microbial consortia, together with full-scale life-cycle assessment, will accelerate the application of the AOPs–Anammox technology for sustainable HSAOW treatment.