Department of Environmental and Resource Engineering, Technical University of Denmark, Bygningstorvet, Building 115, 2800 Kgs. Lyngby, Denmark.
Department of Environmental and Resource Engineering, Technical University of Denmark, Bygningstorvet, Building 115, 2800 Kgs. Lyngby, Denmark.
Sci Total Environ. 2023 Sep 15;891:164329. doi: 10.1016/j.scitotenv.2023.164329. Epub 2023 May 25.
Membrane-aerated biofilm reactors (MABRs) are an emerging technology for nutrient removal; however, a trade-off remains between their removal rate and oxygen transfer efficiency. This study compares nitrifying flow-through MABRs operated under continuous and intermittent aeration modes at mainstream wastewater ammonia levels. The intermittently-aerated MABRs maintained maximal nitrification rates, including under conditions allowing the oxygen partial pressure on the gas side of the membrane to considerably drop during the no-aeration period. Nitrous oxide emissions of all reactors were comparable and amounted to approximately 20 % of the converted ammonia. Intermittent aeration increased the transformation rate constant of atenolol, yet did not affect the removal of sulfamethoxazole. Seven additional trace organic chemicals were not biodegraded by any of the reactors. The ammonia-oxidizing bacteria in the intermittently-aerated MABRs were dominated by Nitrosospira, previously shown to be abundant at low oxygen concentrations and provide reactor stability under changing conditions. Our findings indicate that intermittently-aerated flow-through MABRs can achieve high nitrification rates and oxygen transfer efficiencies, highlighting the possible implications of air supply discontinuity on nitrous oxide emissions and trace organic chemical biotransformation.
膜曝气生物膜反应器（MABRs）是一种新兴的脱氮技术，但在其去除率和氧气转移效率之间仍存在权衡。本研究比较了在主流废水氨水平下连续和间歇曝气模式下运行的硝化流量式 MABR。间歇曝气的 MABR 保持了最大的硝化速率，包括在曝气期间膜气体侧的氧气分压可显著下降的条件下。所有反应器的氧化亚氮排放量相当，约为转化氨的 20%。间歇曝气增加了阿替洛尔的转化速率常数，但不影响磺胺甲恶唑的去除。其他七种痕量有机化学品均未被任何反应器生物降解。间歇曝气的 MABR 中的氨氧化菌主要由 Nitrosospira 组成，此前已证明该菌在低氧浓度下丰富，并在不断变化的条件下为反应器提供稳定性。我们的研究结果表明，间歇曝气的流量式 MABR 可以实现高硝化速率和氧气转移效率，突出了空气供应不连续性对氧化亚氮排放和痕量有机化学物质生物转化的可能影响。
