缓释碳源填充管式生物反应装置强化脱氮性能及其微生物分布特征

为研究缓释碳源填充管式生物反应装置（TBD）对不同氮组分生活污水的脱氮性能及机理，考察中试规模的TBD在3种不同溶解氧（DO）、氨氮（NH₄ ⁺-N）及硝氮（NO₃ ⁻-N）浓度工况下的实际运行效果，同时监测TBD沿程的DO浓度、碳氮比（C/N）、碳源等环境因子变化情况，并在运行期末对TBD的管内基质进行16S rRNA多样性高通量测序。结果表明：3种工况条件下TBD对污水中NH₄ ⁺-N、NO₃ ⁻-N和总氮（TN）的去除率均达90%以上，TBD具有良好的脱氮性能；缓释碳源有助于TBD沿程C/N的增加，且TBD出水COD_Cr始终低于GB 3838—2002《地表水环境质量标准》Ⅴ类水质标准限值，表明TBD在强化脱氮的同时不会产生有机质过量排放问题。此外，TBD中DO浓度沿程递减，形成了好氧-缺氧沿程分布的特征，且该特征促进了好氧反硝化-缺氧反硝化菌属在TBD的沿程分布。

Enhanced denitrification performance and microbial distribution characteristics of Tubular Bio-reactor Device filled with slow-release carbon source

To study the denitrification performance and mechanism of tubular bio-reactor device (TBD) filled with slow-release carbon source for domestic sewage with different nitrogen components, the actual operation effect of TBD in pilot scale under three different concentrations of dissolved oxygen (DO), ammonia nitrogen (NH4 +-N) and nitrate nitrogen (NO3 −-N) was investigated. At the same time, the change trends of environmental factors such as DO concentration, carbon-nitrogen ratio (C/N ratio), and carbon source along the TBD were monitored, and 16S rRNA diversity high-throughput sequencing of the matrix in the tube of TBD was conducted at the end of the operation period. The results showed that the removal rates of NH4 +-N, NO3 −-N and total nitrogen (TN) in sewage by TBD under three working conditions were more than 90%, proving that TBD had good denitrification performance. The slow-release carbon source contributed to the increase of C/N ratio along the TBD, and CODCr of TBD effluent was always lower than the Class Ⅴ standard of Environmental Quality Standards for Surface Water (GB 3838-2002), which indicated that the TBD did not produce excessive organic matter emission during enhanced nitrogen removal. Furthermore, the decrease of DO concentration along the process formed the characteristics of aerobic hypoxia distribution along the TBD and promoted the distribution of aerobic denitrification-anoxic denitrification bacteria along the TBD.