给水管网中水流流速对生物膜形成的影响

Influence of Flow Rate on Biofilm Formation in Water Supply Network

给水管网中有95%的细菌以附着形式存在,水动力的胁迫会影响到细菌在载体表面的附着,适当的流速会刺激细菌增长和胞外聚合物分泌。以自来水中细菌为研究对象,通过构建动态模拟装置实验平台,借助活死细胞染色、Lowry蛋白法、硫酸蒽酮法等分析方法来观测不同流态下生物膜上总细胞数及其胞外聚合物的分泌情况,剖析水流流速对生物膜形成的影响。结果表明,中等流速(0.7 m/s)可以促进生物膜上细菌生长和胞外聚合物分泌,高剪切力又会抑制生物膜生长;中度流速下主体水中胶体最不稳定,有利于细菌向载体表面附着。

In water supply network,95%of bacteria exist in the form of adhesion.Hydrodynamic stress will affect the adhesion of bacteria on the carrier surface,and the appropriate flow rate will stimulate the growth of bacteria and extracellular polymer secretion.In this paper,the bacteria in tap water were taken as the research object,and the experimental platform of dynamic simulation device was constructed.The total number of cells on the biofilm and the secretion of extracellular polymer under different flow states were observed with the help of the analysis methods such as dead staining,Lowry protein method and anthrone sulfate method,so as to analyze the influence of water flow rate on the formation of biofilm.Through this experiment,it is found that the moderate flow rate(0.7 m/s)can promote the growth of bacteria and the secretion of extracellular polymer substances on the biofilm,and the high shear force will inhibit the growth of the biofilm;the colloid in the main body water is the most unstable under the moderate flow rate.Facilitate attachment of bacteria to the surface of the carrier.