典型工业污染物对好氧反硝化菌群脱氮性能及群落结构的影响

针对工业废水中的典型污染物影响城镇污水生物脱氮系统正常运行的问题，以富集筛选到的好氧反硝化菌群为研究对象，深入研究了工业废水中的典型污染物(包括NaCl、Cr(Ⅵ)和TC等)对好氧反硝化菌群的影响机理。结果表明：NaCl、Cr(Ⅵ)和TC均会抑制好氧反硝化菌群的脱氮性能，提高胞外多聚物(EPS)的含量；与此同时，Cr(Ⅵ)和TC的胁迫导致微生物群落多样性减少，降低了napA基因的丰度，然而，NaCl的胁迫呈现相反的变化趋势；NaCl和Cr(Ⅵ)使得菌群中优势菌属由Pseudomonas向Azoarcus转变，反之，TC能够显著增加Pseudomonas的相对丰度，降低Thauera的相对丰度。工业废水中的典型污染物对好氧反硝化菌群的脱氮性能具有较显著的抑制作用，长期胁迫下菌群通过产生胞外多聚物和改变菌群结构来抵御污染物。研究结果对于接纳工业废水的城镇污水处理厂应用好氧反硝化技术进行生物脱氮具有指导和借鉴意义。

Effects of typical industrial pollutants on the denitrification performance and the community structure of aerobic denitrifying bacteria

The normal operation of biological nitrogen removal systems for urban sewage is affected by typical contaminants in industrial wastewater, while the biological nitrogen removal based on pollutant-tolerated aerobic denitrifying bacteria provides a solution to this toxic wastewater treatment. In this study, the effects of typical contaminants in industrial wastewater, i.e., sodium chloride, hexavalent chromium, and tetracycline hydrochloride on the denitrifying performance of the enriched aerobic denitrifying bacteria were investigated. The results showed that these contaminants apparently inhibited the denitrifying performance of aerobic denitrifying bacteria, and enhanced the EPS production. Meanwhile, the long-term stress from hexavalent chromium and tetracycline hydrochloride reduced the diversity of the microbial community and the abundance of napA gene, while the long-term stress from sodium chloride resulted in an opposite trends. The stress of sodium chloride and hexavalent chromium led to the transformation of the dominant genus from Pseudomonas to Azoarcus, but the stress of tetracycline hydrochloride could significantly improve the relative abundance of Pseudomonas, and reduce that of Thauera. Although the initial significant inhibitory effect by typical industrial contaminants on the performance of aerobic denitrifying bacteria occurred, these bacteria could produce extracellular polymers and change their microbial community structure to relieve this inhibitory effect under long-term stress conditions. The study can provide a reference for the practical application of aerobic denitrification technology for bio-denitrification in urban sewage treatment plants with admission of industrial wastewater.