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目的:在市政供水管网系统中,由冲刷引起的管道内壁生物膜脱落可能造成饮用水二次污染。本文旨在通过研究冲刷前后生物膜理化特性和微生物种群结构的变化,探讨不同金属管材管道和不同冲刷流速对生物膜脱落的影响,从而为管道生物安全的风险评估提供科学依据。创新点:不同菌属的细菌对水力冲刷的敏感程度不同;各菌属对水力变化的敏感程度既与菌属本身的性质有关,也与其附着生长的管材有关。方法:1.采用R2A培养基平板计数、16S rD NA检测、荧光定量聚合酶链式反应及454焦磷酸测序技术。2.通过理化指标检测与测序相结合的方式进行分析,并以丰度图和热度图的形式呈现结果。结论:1.球墨铸铁管内壁生物膜的抗水力剪切能力较强,能够抵抗低剪切冲刷,在高剪切力冲刷后才会明显脱落,而灰口铸铁管和不锈钢复合管内壁生物膜的抗水力剪切能力较弱,低剪切力冲刷工况便会导致生物膜的明显脱落。2.生物膜对冲刷的抵抗作用在其群落的属水平和纲水平上有显著变化,这与群落本身和管材特性均有关联。
OBJECTIVE: In municipal water supply pipe network systems, biofilm removal from the inner walls of pipelines caused by erosion may cause secondary pollution of drinking water. The purpose of this paper is to study the physical and chemical properties of biofilms before and after washing and the changes of microbial population structure to explore the impact of different metal pipelines and different scouring flow rates on biofilm shedding so as to provide a scientific basis for the risk assessment of biological safety of pipelines. Innovative point: bacteria of different genus are sensitive to hydraulic scouring; the susceptibility of each genus to hydraulic changes is not only related to the nature of the genus, but also to the pipe to which it is attached. Using R2A medium plate count, 16S rD NA detection, fluorescence quantitative polymerase chain reaction and 454 pyrosequencing technology. Through physical and chemical index detection and sequencing combined with the way of analysis, and the abundance and heat map in the form of the results presented. Biofilms on the inner wall of ductile iron pipe are more resistant to hydro-shearing, resistant to low-shear scour, and will not come off significantly after high-shear-force scouring. However, the biofilm of gray cast iron pipe and stainless steel composite pipe inner wall biofilm Of the hydraulic shear capacity is weak, low shear force scouring conditions will lead to significant loss of biofilm. The biofilm resistance to scouring had significant changes in the genus and level of its community, which were related to the community itself and the characteristics of the pipe.