Long-term performance of ZVI-stimulating anaerobic/aerobic system - PEI modified ceramic membrane SMBR in reusing food wastewater for irrigation: An industrial project and microbial community shift

A large-scale project was carried out using an integrated treatment system composed of anaerobic and aerobic unit followed by ceramic membrane SMBR for reclaiming 200 m3/d of food wastewater for the purpose of irrigation. Utilization of ZVI technology to facilitate the organic contaminants degradation in UASB and aerobic unit in the operation of successive 240 days was investigated. A membrane flux of around 30 LMH was stably attained in a novel PEI-modified flat sheet ceramic membrane SMBR equipped with in situ intensive mechanical cleaning bush system. The ceramic MBR system investigated had significantly alleviated membrane fouling and no severe membrane fouling occurred throughout the whole filtration process. Overall, the combined treatment system can produce high quality reusable water for irrigation and the final effluent had a COD of around 120 mg/L and BOD5 of around 32 mg/L, respectively. Finally, variations in dominant species in both initial sludge Day-1 and sludge Day-240 in ZVI assisting UASB and aerobic unit was further unraveled by the high throughput sequencing analysis.