[Performance and Membrane Fouling Characteristics of Mariculture Wastewater Treated by Anoxic MBR-MMR].

An anoxic membrane bioreactor-microalgae membrane reactor coupling system (anoxic MBR-MMR) was used to deal with mariculture wastewater. Pre-anoxic MBR was used for the degradation of organic matter, NO-N and NO-N, and the released NH-N entered MMR for microalgae growth and was removed. Meanwhile, the treatment efficiency and the microalgae recovery were studied, and the membrane fouling behavior was investigated. After running for 91 days, the removal rates of the system toward NO-N and NH-N were stable at above 90.0% and 88.0%, respectively. Furthermore, the average removal rates of PO-P and TOC were 49.4% and 84.7%, respectively. Under the condition that the microalgae were harvested continuously, the biomass can be stably operated at an average concentration of 9×10 cells·mL and good removal efficiency and resource utilization could be achieved. Through infrared spectrum and three-dimensional fluorescence spectrum analysis, the main substances causing membrane fouling in MMR were tryptophan proteins and humic acids. The membrane fouling in MMR was lighter than that in anoxic MBR.