National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
Sci Total Environ. 2021 Nov 1;793:148581. doi: 10.1016/j.scitotenv.2021.148581. Epub 2021 Jun 22.
Denitrifying phosphorus removal (DPR) technology is one of the most effective approach to simultaneously realize nitrogen (N) and phosphorus (P) removal from low COD/N ratio wastewater. Identifying the interaction of denitrifying phosphate-accumulating organisms (DPAOs), denitrifying glycogen organisms (DGAOs) and denitrifying ordinary heterotrophic organisms (DOHOs) is critical for optimizing denitrification and anoxic P uptake efficiency in DPR processes. In this study, a novel DPR system of anaerobic anoxic oxic - biological contact oxidation (AAO-BCO) was employed to dispose actual sewage with various influent COD/N ratios (3.5-6.7). High efficiency of TIN (76.5%) and PO-P (94.4%) removal was observed when COD/N ratio was between 4.4 and 5.9. At the COD/N ratio of 5.7 ± 0.2, prominent DPR performance was verified by the superior DPR efficiency (88.7%) and anoxic phosphorus uptake capacity (PUA/ΔTIN = 1.84 mg/mg), which was further proved by the preponderance of DPAOs in C, N and P removal pathways. GAOs have a competitive advantage over PAOs for COD utilization at low COD/N ratio of 3.7 ± 0.2, which further limited the N removal efficiency. High proportion of N removal via DOHOs (21.2%) at the COD/N ratio of 6.5 ± 0.2 restrained the DPR performance, which should be attributed to the outcompete of DOHOs for NO. The nutrient removal mechanisms were explicated by stoichiometric calculation methodology to quantify the contribution of diverse functional microorganisms, contributing to improving the robustness of AAO-BCO system when facing the fluctuation of influent carbon source concentration.
反硝化除磷（DPR）技术是同时实现低 COD/N 比废水中氮（N）和磷（P）去除的最有效方法之一。确定反硝化聚磷菌（DPAOs）、反硝化糖原菌（DGAOs）和反硝化普通异养菌（DOHOs）的相互作用对于优化 DPR 过程中的反硝化和缺氧吸磷效率至关重要。在本研究中，采用新型厌氧缺氧好氧-生物接触氧化（AAO-BCO）DPR 系统处理不同进水 COD/N 比（3.5-6.7）的实际污水。当 COD/N 比在 4.4 到 5.9 之间时，TIN（76.5%）和 PO-P（94.4%）的去除效率很高。在 COD/N 比为 5.7±0.2 时，通过卓越的 DPR 效率（88.7%）和缺氧吸磷能力（PUA/ΔTIN=1.84mg/mg）验证了显著的 DPR 性能，这进一步证明了在 C、N 和 P 去除途径中 DPAOs 的优势。在低 COD/N 比为 3.7±0.2 时，GAOs 对 COD 的利用具有竞争优势，进一步限制了 N 的去除效率。在 COD/N 比为 6.5±0.2 时，通过 DOHOs 去除的高比例 N（21.2%）限制了 DPR 性能，这归因于 DOHOs 对 NO 的竞争。通过化学计量计算方法阐明了养分去除机制，以量化不同功能微生物的贡献，有助于提高 AAO-BCO 系统在面对进水碳源浓度波动时的鲁棒性。
