中文摘要：

为探究低碳氮比条件下3DBER-S（三维电极生物膜与硫自养耦合脱氮工艺）阴极反硝化菌群特征、强化脱氮机制,在TOC/TN=0.36的进水条件下稳定运行反应器,运用nir S基因克隆文库方法,分析了3DBER-S阴极生物膜反硝化菌群结构。结果表明,在3DBER-S阴极生物膜上反硝化菌中,β变形菌（β-proteobacteria）是优势菌种,占细菌总数的59.22%。其中,所占比例最大的是异养菌,包括与固氮弧菌属（Azoarcus tolulyticus）和趋磁螺菌（Magnetospirillum magneticum）类似的细菌,分别占44.74%和21.05%。能够分别利用硫单质或氢气作为电子供体进行反硝化脱氮的Sulfuricella denitrifican、高氯酸盐降解菌（Dechlorospirillum sp.）和陶厄氏菌属（Thauera）三者所占比例之和达到了17.11%。表明系统中氮的去除是由异养反硝化、氢自养反硝化和硫自养反硝化共同作用的结果,既有效减少了脱氮过程中有机碳源的消耗,又维持了系统酸碱度的平衡,从而能够在低碳氮比条件下维持稳定高效的脱氮效果。

英文摘要：

To investigate the features of denitrifying bacteria in a cathode of a 3DBER-S reactor and enhance the nitrogen removal mechanism in low carbon-to-nitrogen ratio conditions,the community structure of denitrifying bacteria in cathode biofilms was analyzed using a nir S gene clone library after stably operating the reactor under TOC / TN = 0. 36 in the influent. The dominant class was β-proteobacteria,which accounted for59. 22% of all denitrifying bacteria. Among the denitrifying bacteria,the most highly represented species were similar to Azoarcus tolulyticus and Magnetospirillum magneticum,which accounted for 44. 74% and 21. 05% of species,respectively. The total proportion of species that were Sulfuricella denitrificans,Dechlorospirillum sp.and Thauera sp. reached 17. 11%; these three kinds of bacteria use elemental sulfur or hydrogen as an electron donor for denitrification. In conclusion,nitrogen removal depended on heterotrophic denitrification,hydrogen autotrophic denitrification,and sulfur autotrophic denitrification. Not only did it reduce the consumption of the organic carbon source,but it also maintained the p H balance of the system. Thus,a stable and efficient nitrogen removal system can be maintained in low carbon-to-nitrogen ratio conditions.