原水水质对输送管道中含氮污染物转化和生物膜的影响

Effect of Raw Water Quality on Transformation of Nitrogenous Pollutants and Biofilm in Raw Water Diversion Pipelines

原水的水质条件会影响原水输水管道内含氮污染物的转化。采用2套模拟管道装置,对不同原水水质条件下含氮污染物的转化以及微生物种群结构进行探究。结果表明,A、B两种原水在管道中均会发生硝化反应,NH4+-N和NO2--N的含量降低,NO3--N的浓度增高,原水水质较差的A水源水在管道中的硝化反应更为明显,且出水中出现更多比例的小分子溶解性有机氮(DON)。由于水中藻类较多,A水源水在出水中产生了更多比例的亲水性DON物质。仅当水源水不同时,原水营养水平高的管道中的微生物存在水平也相应更高,不同原水水质的输送管道内壁生物膜中的优势菌门基本一致,但各优势菌门的丰度不同,且原水水质好可促进管道内的生物多样性。

Quality of raw water can affect the conversion of nitrogenous pollutants in raw water diversion pipelines.Two sets of simulating pipeline devices were used to explore the transformation of nitrogenous pollutants in raw water and microbial population structure under different raw water quality conditions.Results showed that nitrification occurred in both A and B raw water diversion pipelines.The content of NH4+-N and NO2--N decreased,while the concentration of NO3--N increased.Nitrification reaction was more obvious in raw water with poor water quality of A source water in the pipeline,and more small molecules of dissolved organic nitrogen(DON)appeared in outlet water.As there were more algae in A source water,there were a higher proportion of hydrophilic DON substances in outlet water.Only when the water was of different sources,the level of microbial presence in diversion pipeline with a higher nutrient level of raw water was also correspondingly higher.The dominant bacteria phylum in the biofilm of diversion pipelines with different raw water quality was basically the same,but the abundance of each dominant bacteria phylum was different.Better quality of raw water promoted greater biological diversity in diversion pipelines.