Iron-carbon (Fe-C) micro-electrolysis coupling with anaerobic-anoxic-oxic (A2/O) process: Nitrogen and phosphorus removal performance and microbial characteristics

For exploring the nitrogen and phosphorus removal performance of iron-carbon (Fe-C) micro-electrolysis pretreatment coupling with anaerobic-anoxic-oxic (A(2)/O) process, a pilot experiment was constructed and microbial community structure of A(2)/O process was investigated by high-throughput sequencing. The results showed that Fe-C micro-electrolysis could reduce the toxicity of refractory organic compounds (ROC) and improve wastewater biodegradability. Though sodium dodecyl benzene sulfonate (SDBS) contributed to the accumulation of ammonia nitrogen (NH4+-N) by inhibiting nitrifying process, the chemical oxygen demand (COD), total nitrogen (TN), NH4+-N and total phosphorus (TP) in effluent reached 75.80, 0.65, 0.62, 0.74 mg (L-1), respectively, with the addition of 40% Fe-C micro-electrolysis effluent (met the discharged standards of China (GB21900-2008)). High-throughput sequencing results demonstrated that the greatest changes occurred in anaerobic unit, and the dominant microbial genera were Aeromonas, Enterobacter, uncultured_bacterium_c_Gammaproteobacteria, Zoogloea and Acidovorax.