硫自养反硝化系统运行效能和微生物群落结构研究

启动了单质硫自养反硝化反应器并研究其脱氮性能，通过血清瓶批式实验测定了污泥的反硝化活性，并采用扫描电镜和高通量测序手段揭示了系统内微生物群落结构特征.结果表明，SBR反应器进水NO₃^--N浓度为80mg/L，随水力停留时间由12h逐渐缩短为6h，反应器的自养脱氮性能逐渐增强，稳定期反应器的总无机氮去除率达99.1%，总无机氮去除负荷平均值为0.158kg N/（m³·d）；SBR周期内NO₂^--N浓度最大值为13.3mg/L，NO₃^--N还原为NO₂^--N过程pH值由7.38降低至6.94，NO₂^--N还原为N₂过程pH值基本不变；批式实验结果表明，硫自养反硝化和异养反硝化NO₃^--N去除速率分别为0.515，0.196kg N/（kg VSS·d），硫自养反硝化污泥NO₂^--N降解速率为0.117kg N/（kg VSS·d），污泥同时具有自养反硝化和异养反硝化活性；扫描电镜显示，污泥中存在大量的杆状细菌和球状菌；污泥中主要的硫反硝化细菌分别为Thiobacillus、Sulfurimonas和Thermomonas属，其相对丰度分别为14.5%、7.6%和6.0%.

Study on operation efficiency and microbial community structure of sulfur-based autotrophic denitrification system

The sulfur-based autotrophic denitrification reactor was set up and its denitrification performance was evaluated in this study. The denitrification activity of the sludge was determined by batch tests, and the microbial community structure was revealed by scanning electron microscopy(SEM) and high-throughput sequencing. The influent NO₃^--N concentration of the reactor operated with sequencing batch mode was 80mg/L. The autotrophic denitrification performance increased with the hydraulic retention time (HRT) gradually shortened from 12h to 6h, the total inorganic nitrogen(TIN) removal efficiency and the average TIN removal loading rate of the reactor during the stable period were 99.1% and 0.158kg N/(m³·d), respectively. The maximum NO₂^--N concentration during the SBR cycle was 13.3mg/L, the pH value decreased from 7.38 to 6.94 during the reduction process from NO₃^--N to NO₂^--N, and the pH value remained stable during the process of reducing NO₂^--N to N₂. The batch test results showed that the NO₃^--N removal rate of sulfur autotrophic denitrifying bacteria and heterotrophic denitrifying bacteria were 0.515and 0.196kg N/(kg VSS·d), respectively, and the NO₂^--N removal rate of sulfur autotrophic denitrifying bacteria was 0.117kg N/(kg VSS·d), the sludge had both autotrophic denitrification activity and heterotrophic denitrification activity. SEM images showed that both rod-shaped bacteria and spherical bacteria were observed in the sludge. The dominant sulfur autotrophic denitrifying bacteria in the sludge were Thiobacillus, Sulfurimonas and Thermomonas, with relative abundance of 14.5%, 7.6% and 6.0%, respectively.