The emissions of two major greenhouse gases, i.e., CH₄ and N₂O, during the treatment of partially stabilized municipal solid waste leachate by a practical-scale two-stage membrane bioreactor (MBR) were investigated. The system consisted of anoxic and aerobic reactors that had a total hydraulic retention time (HRT) of 4 days and were operated with internal sludge recirculation at 100% of the influent flow rate. At steady operation, high organic and nitrogen removals of 99% for BOD, 97% for COD, 99% for TOC and 94% for TKN were achieved. During operation, high direct CH₄ emissions from the anoxic reactor, accounting for 90% of the total emissions from the system and 16.2% of the total organic carbon mass removed, were observed. N₂O was emitted to a much lower extent, and N₂O emissions varied much less between the reactors. The presence of methane- and nitrous oxide-producing bacteria was confirmed by PCR-DGGE and real-time PCR analyses. The operation of the two-stage MBR with sludge recirculation enabled the co-existence of CH₄- and N₂O-producing microorganisms in the sludge from the anoxic and aerobic reactors, with an approximately 30% difference in their microbial communities.

通过实用规模的两级膜生物反应器（MBR）研究了部分稳定的城市固体垃圾渗滤液处理过程中两种主要温室气体（CH ₄和N ₂ O）的排放。该系统由缺氧和好氧反应器组成，它们的总水力停留时间（HRT）为4天，在内部污泥再循环的情况下以进水流量的100％运行。在稳定运行下，BOD的有机和氮去除率高达99％，COD的去除率为97％，TOC的去除率为99％，TKN的去除率为94％。在运行过程中，观察到来自缺氧反应器的较高的直接CH ₄排放量，占系统总排放量的90％和所除去的有机碳总量的16.2％。N ₂O的排放量要低得多，N ₂ O的排放量在反应堆之间的变化要小得多。通过PCR-DGGE和实时PCR分析确认了产生甲烷和一氧化二氮的细菌的存在。具有污泥再循环的两级MBR的操作使缺氧和好氧反应器的污泥中共生成CH ₄和N ₂ O的微生物共存，其微生物群落相差约30％。