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Simultaneous nitrogen and phosphorus removal by combined anammox and denitrifying phosphorus removal process

Zhang, Meijiao, Qiao, Sen, Shao, Donghai, Jin, Ruofei, Zhou, Jiti
Journal of chemical technology and biotechnology 2018 v.93 no.1 pp. 94-104
Nitrosomonas, Rhodocyclales, acetates, anaerobic ammonium oxidation, carbon, chemical oxygen demand, denitrification, nitrates, nitrifying bacteria, nitrogen, nitrogen content, phosphorus, wastewater
BACKGROUND: Single‐stage nitrogen removal using anammox and partial nitrification process (SNAP process) is a promising process to treat low C/N wastewater relying on ammonia‐oxidizing bacteria (AOB) and anaerobic ammonium oxidation (anammox) bacteria. However, excess nitrate (NO₃ ⁻) in effluent is a common problem for the SNAP process. The denitrifying phosphorus removal (DPAO) process using NO₃ ⁻ as electron acceptor was adopted to reduce nitrate in effluent from the SNAP process, while phosphorus removal was also achieved simultaneously. Thus, a novel combined process (DPAO‐SNAP process) was established to achieve nitrogen and phosphorus removal simultaneously. RESULTS: The DPAO‐SNAP process achieved average 95.7% chemical oxygen demand, 98.2% total nitrogen and 97.8% total phosphorus removal efficiencies during stable stages. Furthermore, Candidatus Kuenenia and Nitrosomonas were identified as the dominant genus for anammox bacteria and AOB, respectively. Defluviicoccus was enriched as the glycogen‐accumulating microorganism (GAOs) for the DPAO process with acetate as the carbon source, while Rhodocyclales was the dominant genus in the DPAO process with mixed carbon source. CONCLUSION: This DPAO‐SNAP process could not only resolve the problem of effluent NO₃ ⁻ in the SNAP process but also simultaneously achieved high removal efficiency of COD, TN and TP with a low need for carbon sources (COD/N/P=25:15:1). © 2017 Society of Chemical Industry