不同生境氨氮浓度及悬浮污泥对厌氧氨氧化生物膜特性的协同影响

生物膜技术是厌氧氨氧化工艺应用的关键，但关于不同生境氨氮浓度和悬浮污泥协同作用下形成的生物膜特性鲜有报道。本研究在推流式固定生物膜-活性污泥反应器中，发现在高氨氮浓度下生长的生物膜具有较高的污泥量和厚度，但低氨氮浓度生长的生物膜具有更高的厌氧氨氧化菌丰度((4.91±0.65)×10⁹ 拷贝数·g⁻¹，P<0.05)和厌氧氨氧化比活性(6.53 mg·(g·h)⁻¹)。高通量分析结果表明，Candidatus Brocadia是生物膜和悬浮污泥中主要的厌氧氨氧化菌，在两类生物膜上的丰度未有显著差异；在低氨氮浓度生物膜中Candidatus Jettenia的相对丰度显著高于高氨氮浓度的生物膜，但Candidatus Kuenenia的丰度则相反。综合分析发现，厌氧氨氧化菌种的附着生长与悬浮污泥群落多样性的初始定殖有关，而低丰度菌种的分布则受不同生境的影响，该结果表明不同氨氮浓度和悬浮污泥类型的选择对生物膜的协同影响不可忽略。

Synergistic effects of different habitats ammonia concentration and suspended sludge on anammox biofilm characteristics

Biofilm technology is the key to the application of anaerobic ammonia oxidation process, but there are few reports on the characteristics of biofilms formed under synergistic effect of different ammonia nitrogen concentrations and suspended sludge. In this study, in a plug-flow fixed biofilm-activated sludge reactor, the biofilm sludge concentration and thickness under high ammonia nitrogen concentration conditions were greater than those under low ammonia nitrogen concentration, but the latter had higher anammox bacteria abundance ((4.91±0.65)×109 copies·g−1, P<0.05) and activity (6.53 mg·(g·h)−1). High-throughput analysis showed that Candidatus Brocadia was the major anaerobic ammonia oxidation bacteria in both biofilms and suspended sludge, and there was no significant difference in abundance between the two types of biofilms. The relative abundance of Candidatus Jettenia was significantly higher in biofilms at low ammonia nitrogen concentrations than at high ammonia nitrogen concentrations, but the abundance of Candidatus Kuenenia was the opposite. Comprehensive analysis revealed that the attachment growth of anaerobic ammonia oxidation bacteria was related to the initial colonization of suspended sludge community diversity, while the distribution of low abundance AnAOB was influenced by different microhabitats. This study suggests that the synergistic effect of different ammonia nitrogen concentrations and suspended sludge types on biofilms should not be neglected.