Interdisciplinary Graduate School, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore; Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore.
Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Sci Total Environ. 2022 Apr 20;818:151758. doi: 10.1016/j.scitotenv.2021.151758. Epub 2021 Nov 18.
Nitrogen removal via anammox is a promising and sustainable solution in mainstream wastewater treatment. To maintain stable anammox process, competitors of anammox bacteria should be suppressed while cooperators need to be favoured. This study demonstrated a synchronous aerobic and anaerobic ammonium removal process in a membrane aerated biofilm reactor (MABR) under minimal lumen pressure. By adjusting the lumen pressure, aerobic and anaerobic ammonium oxidation rate can be synchronized to minimize interference of nitrite oxidizing bacteria (NOB) by limiting NOB's access to both oxygen and nitrite. Long-term performance indicated that PN/A in MABR could be achieved at zero positive aeration pressure. Furthermore, by connecting two MABRs in series, high total nitrogen (TN) removal efficiency of 71.1% ± 5.3% was attained with a TN removal rate of 30.1 ± 3.2 mg-N/L/d. The organic carbon present in the wastewater reduced the nitrate concentration in the effluent while not affecting the overall nitrogen removal efficiency and rate. Real-time qPCR analysis suggested that the abundance of amoA gene was relatively stable while K-strategist Nitrospira 16S rRNA gene did not surge in the long-term operation. High throughput sequencing showed that Candidatus Brocadia and uncultured anaerobic ammonium oxidizing bacteria from Chloroflexi were the most abundant anammox taxa. Denitrifiers, such as Denitratisoma may be responsible to reduce the nitrate in the effluent.
通过厌氧氨氧化脱氮是主流废水处理中一种很有前途且可持续的解决方案。为了维持稳定的厌氧氨氧化过程，需要抑制厌氧氨氧化菌的竞争者，同时需要有利于合作者。本研究在最小内腔压力下，在膜曝气生物膜反应器（MABR）中展示了一种同步好氧和厌氧氨氧化去除过程。通过调节内腔压力，可以同步好氧和厌氧氨氧化速率，通过限制亚硝酸氧化菌（NOB）对氧气和亚硝酸盐的同时获取，最小化亚硝酸氧化菌的干扰。长期性能表明，在零正曝气压力下可以实现 MABR 中的 PN/A。此外，通过将两个 MABR 串联连接，可以实现高总氮（TN）去除效率 71.1%±5.3%，TN 去除率为 30.1±3.2mg-N/L/d。废水中存在的有机碳降低了出水硝酸盐浓度，而不影响总氮去除效率和速率。实时 qPCR 分析表明，amoA 基因的丰度相对稳定，而 K 策略性的 Nitrospira 16S rRNA 基因在长期运行中并未激增。高通量测序表明，Candidatus Brocadia 和未培养的厌氧氨氧化菌 Chloroflexi 是最丰富的厌氧氨氧化菌类群。反硝化菌，如 Denitratisoma 可能负责降低出水中的硝酸盐。
