Abstract: For the anaerobic biogas slurry, and other industrial and domestic wastewater produced from a food waste treatment plant in Zhejiang, the “regulating tank + air flotation + MBR built-in membrane + nanofiltration system” process was adopted, and the main indicators of effluent complied with the third-level standards of GB 8978—1996 Integrated Wastewater Discharge Standard. Through a series of process design optimization measures such as strengthening pretreatment to remove oil and impurities, extending biochemical retention time, and increasing reflux multiples, the treatment effects of relevant operation data during debugging were analyzed. Under pre-treatment settings with multi-precision interception of solids, a total hydraulic retention time in the bioreactor of 16.17 days, and a 48-fold recirculation rate, the removal rates of CODCr, ammonia nitrogen, and total nitrogen by membrane bioreactor were not less than (96.15±1.75)%, (99.64±0.17)%, and (97.14±0.59)%, respectively, and the effluent from MBR ultrafiltration could stably meet the standards. The system demonstrates excellent treatment performance, operates with high energy efficiency and low carbon emissions, and possesses strong economic viability and broad application potential.

Key words: food waste, anaerobic digestate, in-built MBR, design optimization, debugging effect