中文摘要：

利用全比例非循环管网中试平台的球墨铸铁管模拟不同水流剪切力下管壁生物膜的生长.采用总固体（TS）、挥发性固体（VS）和化学需氧量（COD）表征生物膜的理化特性,实时荧光定量PCR和RT-PCR计数细菌总数和活菌数量,高通量测序（454焦磷酸测序）探究生物膜、细菌种群多样性.结果表明,水流剪切力对管壁生物膜理化指标细菌总数和细菌种群结构有显著影响（理化参数p〈0.05）,但对活菌数量的影响并不显著（p〉0.05）.并且生物膜的理化指标、细菌数量并不是随水流剪切力的增大而简单地增大或减小,存在生物膜生长的最佳水流剪切力.在水流剪切力为0.8Pa下生物膜生物量最大,每平方厘米管壁细菌总数高达2.10×10^9个,而在水流剪切力为0.05和2.5Pa下每平方厘米管壁细菌总数分别为2.20×10^8和2.27×10^8个.

英文摘要：

A full scale,non-circulated experimental facility with ductile cast iron pipes was used to simulate the growth of biofilm.The physicochemical properties of biofilm were analyzed by total solid（TS）,volatile solid（VS）and chemical oxygen demand（COD）.Real-time fluorescence quantification PCR and RT-PCR were used to count the numbers of total bacteria and viable bacteria,respectively.Highthroughput sequencing（454-Pyrosequencing）was also used to study the microbial diversity of biofilm.The results show that shear stress has an obvious influence on the physico-chemical parameters,total bacteria and bacterial communities of biofilm（p〈0.05）but weak influence on viable bacteria（p〈0.05）.The physico-chemical parameters and bacterial quantity of biofilm don＇t simply increase or decrease with a same tendency as shear stress increases.An optimal shear stress exists for biofilm to develop on pipe inner walls in DWDS.The number of total bacteria in biofilm under 0.8Pa shear stress is the largest,which is up to 2.10×10^9 per square centimetre,while under 0.05 Pa and 2.5Pa shear stres the number is 2.20×10^8 and 2.27×10^8 per square centimetre,respectively.