Biological nitrogen removal and metabolic characteristics in a full-scale two-staged anoxic-oxic (A/O) system to treat optoelectronic wastewater

In order to explore the treatment efficiency of optoelectronic wastewater and pollutant degradation mechanism of full-scale two-stage AO process, 160 d monitoring was conducted in this study. The results showed that the two-stage AO process owned relatively stable nitrogen and organic matter removal performance. The average concentration of COD, NH4+-N, and TN in effluent was 54, 3.78 and 13.77 mg L−1, respectively, and the removal rate was over 80%. The results of high-throughput sequencing demonstrated that the dominant microorganism was Proteobacteria, Bacteroidetes, Firmicutes, Chlorofeli, and Acidobacteria, and differences of interaction networks exited between aerobic and anoxic units. Meanwhile, the microorganism metabolism in aerobic units was significantly different from that in anoxic unit, and the metabolism of the microbial community for treating optoelectronic wastewater was significantly different from that for treating urban domestic sewage.