Dissolved methane is a hurdle for anaerobic wastewater treatment, which would be stripped into the atmosphere by conventional bubble aeration and increase the release of greenhouse gases into the environment. The high oxygen transfer efficiency and less turbulence in membrane aerated biofilm reactor (MABR) could prevent the stripping of dissolved methane. In this study, an MABR was established to remove dissolved methane aerobically in parallel to the nitrogen removal driven by the anammox process. The long-term results demonstrated that aerobic methane oxidation has a short start-up period, in which a high level (>90 %) of dissolved methane removal was achieved in 20 days. Meanwhile, the anammox-based nitrogen removal process reached a total nitrogen removal rate of ∼150 mg N/L/d (0.27 g N/m²/d). In situ batch tests confirmed the active bioreactions of ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, anammox bacteria and aerobic methanotrophs, while 16S rRNA gene amplicon sequencing further validated their existence. Moreover, nitrite/nitrate-dependent anaerobic methane oxidation (n-DAMO) bacteria were enriched to a relative abundance of 2.5 % on Day 372, suggesting their potential role in removing nitrogen and dissolved methane in the MABR. This study provides an alternative technology for removing dissolved methane and nitrogen in parallel from anaerobically treated wastewater.

中文翻译：

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气体输送膜作为替代曝气方法，用于从厌氧处理的废水中去除溶解的甲烷


溶解的甲烷是厌氧废水处理的一个障碍，传统的气泡曝气会将其剥离到大气中，并增加向环境中释放的温室气体。曝气膜生物膜反应器 （MABR） 中的高氧转移效率和较小的湍流可以防止溶解甲烷的剥离。在这项研究中，建立了一个 MABR，以有氧方式去除溶解的甲烷，同时由厌氧氨氧化过程驱动脱氮。长期结果表明，好氧甲烷氧化的启动期很短，在 20 天内实现了高水平的溶解甲烷去除 （>90 %）。同时，基于厌氧氨氧化的脱氮工艺达到了 ∼150 mg N/L/d （0.27 g N/m²/d） 的总脱氮率。原位批量测试证实了氨氧化细菌、亚硝酸盐氧化细菌、厌氧氨氧化细菌和需氧嗜甲烷菌的活性生物反应，而 16S rRNA 基因扩增子测序进一步验证了它们的存在。此外，亚硝酸盐/硝酸盐依赖性厌氧甲烷氧化 （n-DAMO） 细菌在第 372 天富集至 2.5% 的相对丰度，表明它们在去除 MABR 中的氮和溶解甲烷方面具有潜在作用。本研究提供了一种从厌氧处理的废水中并行去除溶解的甲烷和氮气的替代技术。