一体式PN/A耦合EBPR工艺高效低耗处理实际低C/N主流城市污水

针对低C/N城市污水脱氮除磷因碳源不足存在能耗、药耗高以及脱氮除磷效率低等问题，开发一体式短程硝化/厌氧氨氧化 (PN/A) 耦合强化生物除磷工艺 (EBPR) ，以降低碳源消耗和能耗、提高脱氮除磷效率，从而实现高效低耗减污降碳。通过构建悬浮污泥和生物膜共存的混合系统，采用厌氧-好氧运行模式以及间歇曝气，考察短程硝化/厌氧氨氧化与强化生物除磷过程的耦合效果。结果表明，反应器能长期稳定运行，出水总无机氮 (TIN) 质量浓度稳定低于4 mg·L⁻¹，溶解态磷 (DP) 质量浓度约0.2 mg·L⁻¹，TIN平均去除率大于90%，DP的平均去除率大于85%，平均脱氮负荷为53 mg·(g·d)⁻¹，强化间歇曝气能够在系统内实现NOB抑制，亚硝氮积累率可达60%以上，甚至100%。控制悬浮污泥好氧污泥龄为3.5 d，NOB由悬浮污泥向填料转移。由于生物膜传质受限，系统的亚硝氮积累率并未受到影响。该系统内厌氧氨氧化活性提高了5倍，厌氧氨氧化菌以Candidatus Brocadia为主，相对丰度为1.1%，较主流条件下提高了2.75倍。本研究结果证实了主流条件下厌氧氨氧化与传统脱氮除磷工艺耦合的可行性，这表明此耦合工艺具备更好应对水质波动的能力，能保证稳定良好的出水水质。该案例可为低C/N城市污水实现高效低耗减污降碳的脱氮除磷提供参考。

Integrated PN/A and EBPR process for real low C/N mainstream municipal wastewater treatment

An integrated partial nitritation/anammox (PN/A) coupled with enhanced biological phosphorus removal process (EBPR) has been developed to decrease carbon source consumption and energy consumption, as well as improve nitrogen and phosphorus removal efficiency, in response to the problems of energy consumption, high drug consumption, and low efficiency in nitrogen and phosphorus removal of low C/N municipal wastewater due to insufficient carbon source. The operation efficiency of the integrated process was investigated by stablishing a mixed system comprising suspended sludge and biofilm and employing anaerobic-aerobic operation mode and intermittent aeration strategy. The results showed that the reactor operated stably in a long term, with a total inorganic nitrogen (TIN) concentration lower than 4 mg·L−1 and a phosphorus concentration of 0.2 mg·L−1 in the effluent. The average TIN removal efficiency was above 90%, the average P removal rate was over 85%, and the average nitrogen removal rate was 53 mg·(gVSS·d)−1. With enhanced intermittent aeration, nitrite oxidation bacteria (NOB) can be well suppressed in the system and the rate of nitrite nitrogen accumulation reached up to 60% or even 100%. After adopting a tight aerobic sludge age (3.5 days) control for suspended sludge, NOB started to move from suspended sludge to biofilm, however, the accumulation rate of nitrite was unaffected due to the restriction of biofilm mass transfer. The specific anaerobic ammonia oxidation activity in this system has increased by 5 times. Candidatus Brocadia was the dominant anaerobic ammonia oxidizing bacteria genus with a relative abundance of 1.1%, which is 2.75 times greater than under mainstream conditions. This work demonstrated the feasibility of cooperation of PN/A and EBPR for low C/N municipal wastewater treatment. This process has a good ability to cope with quality fluctuations and ensures a stable operation.