尾水排放对河道水质及底泥细菌群落结构影响

Effects of Effluent from Water Purification Plant on River Water Quality and Bacterial Community Composition in Sediment

城镇污水处理厂尾水排放后对河道的影响已逐渐成为当前的研究热点,文章以青岛市某水质净化厂为例,研究了该厂尾水排入张村河后对河道水质以及底泥细菌群落结构的影响。结果表明,水质净化厂通水前,河道大多数断面COD和TN污染较为严重,通水后各项污染指标均明显下降。通水后,上游漫水桥点底泥细菌种群丰富度略有升高,而迷宫堰点显著升高,漫水桥点优势菌占比升高,而迷宫堰点优势菌占比降低;下游点位细菌种群丰富度均略有升高,优势菌占比降低。在门水平上,不论是通水前还是通水后,丰度较高的细菌均为Proteobacteria、Chloroflexi和Firmicutes,在属水平上,通水后下游点位Trichococcus菌的丰度有所下降,而Flavobacterium菌丰度有所上升,上游点位Thiobacillus菌含量有所降低,而下游点位有所升高,与之相反,上游点位Anaerolinea菌含量显著升高,而下游点位则有所降低。通水前Actinobacteria门Brooklawnia属的细菌丰度与通水后差异最显著,而Firmicutes门的显著差异菌最多,通水后Actinobacteria门Ilumatobacter属的细菌丰度与通水前差异最显著,而Proteobacteria门的显著差异菌最多。COD与Trichococcus有最大的正相关,与Thiobacillus有最大的负相关,TN与Flavobacterium呈显著正相关,与Desulfoprunum有最大的负相关,NH_(4)^(+)-N与Anaerolinea和Ilumatobacter呈显著负相关,TP值与Brooklawnia呈显著正相关,与Leptothrix呈显著负相关。

The effect of effluent of wastewater treatment plants on rivers is currently becoming a research focus. This paper considered a water purification plant in Qingdao City as an example to investigate the influence of effluent discharged into Zhangcun River on water quality and the bacterial community structure of sediment. The results indicated that most sections of the river had serious COD and TN pollution before the effluent supply, and all the pollution indexes significantly decreased after effluent supply. Compared with that before effluent supply, the microbial population richness of microorganism at point Manshuiqiao of the upstream slightly enhanced after effluent supply, while that of point Migongyan significantly improved.The dominant microbial population proportion at point Manshuiqiao increased, while that of point Migongyan decreased. The microbial population richness of microorganism at the downstream sites was slightly enhanced, and the dominant microorganism accounted for a lower proportion. Bacteria with high abundance at phylum level mainly included Proteobacteria, Chloroflexi and Firmicutes regardless of before or after effluent supply. At genus level, the abundance of Trichococcus at the downstream sites reduced after effluent supply, but that of Flavobacterium improved. The abundance of Thiobacillus at the upstream sites decreased, while that at the downstream sites increased. On the contrary, the abundance of Anaerolinea at the upstream sites increased, while that at the downstream sites decreased. The abundance of Brooklawnia of Actinobacteria had the most significant difference from that of the genus after effluent supply, but bacteria with significant difference had the most kinds in Firmicutes. And the abundance of Ilumatobacter of Actinobacteria had the most significant difference from that of the genus before effluent supply, but bacteria with significant difference had the most kinds in Proteobacteria. The values of COD had the strongest positive correlation with Trichococcus, and had the strongest negative correlation with Thiobacillus.The values of TN had significantly positive correlation with Flavobacterium, and had the strongest negative correlation with Desulfoprunum. The values of NH_(4)^(+)-N had significantly negative correlation with Anaerolinea and Ilumatobacter. The values of TP had significantly positive correlation with Brooklawnia, and had significantly negative correlation with Leptothrix.