Compact wastewater treatment process based on abiotic nitrogen management achieved high-rate and facile pollutants removal.

[Display omitted] • A CAIRM process was developed by coagulation, NH 4 + exchange – regeneration, and MBR. • CAIRM obtained effluent with 0.3 mg/L NH 4 + and 2.3 mg/L TN within total HRT of 4.6 h. • Long-term operation didn't impair NH 4 + exchange capacity of exchangers. • Membrane fouling was alleviated in MBR with large sludge flocs and good bioactivity. • CAIRM will address insufficient N removal and large footprint of conventional WWTPs. Chemically enhanced primary treatment (CEPT), ammonium ion exchange and regeneration (AIR) and membrane bioreactor (MBR) were coupled as CAIRM to treat domestic wastewater compactly and efficiently. CAIRM achieved efficient removal of chemical oxygen demand, ammonia nitrogen, total nitrogen (TN) and total phosphorus with total hydraulic retention time of 4.6 h, and obtained 2.3 ± 0.9 mg/L TN in the effluent. CEPT removed phosphate and impurities and prevented AIR from pollution. AIR maintained excellent nitrogen removal with a slight decrease in the exchange capacity of ion exchangers. MBR polished the effluent from AIR, and the larger particle size and better dewaterability of sludge mitigated the membrane fouling. Many heterotrophic genera, such as Rhodobacter and Defluviimonas , were enriched in the oligotrophic MBR. This study demonstrates the viability and stability of CAIRM in efficient wastewater treatment, which will address critical challenges in insufficient nitrogen removal and high land occupancy of current processes. [ABSTRACT FROM AUTHOR]