试验给水管网不同给水管材腐蚀的电镜分析及细菌API鉴定

目的研究不同给水管材的腐蚀、结垢及饮用水与生物膜中的菌种情况。方法以实验室模拟给水管网为研究对象,应用环境扫描电镜对目前给水管网中使用较为普遍的镀锌管、PPR管(无规共聚聚丙烯管)和ABS(苯乙烯管)管的腐蚀、结垢情况及结垢层元素组成进行了分析;应用生物梅里埃API(Analytic products NC)细菌鉴定系统10S和20E对饮用水及生物膜中常见的菌种进行了鉴定,并分析了菌种致病性。结果镀锌管的腐蚀、结垢情况最为严重,PPR和ABS管内壁存在薄结垢层。API10S试剂条鉴定实验给水管网水样的10株菌中有7株为条件致病菌;API20E试剂条鉴定水样及生物膜样品的21株菌中5株为致病菌,11株为条件致病菌,其余5株对人体尚无致病报道。结论饮用水管网微生物学水质较差,水及生物膜样品中大多数细菌都为条件致病菌,存在一定的微生物风险。在给水管材方面应加快城市旧管网改造步伐,推广应用新型管材。

Analysis of different pipe corrosion by ESEM and bacteria identification by API in pilot distribution network

OBJECTIVE: To understand the corrosion of different material water supply pipelines and bacterium in drinking water and biofilms. METHODS: A pilot distribution network was built and water quality detection was made on popular pipelines of galvanized iron pipe, PPR and ABS plastic pipes by ESEM (environmental scanning electron microscopy). Bacterium in drinking water and biofilms were identified by API Bacteria Identification System 10s and 20E (Biomerieux, France), and pathogenicity of bacterium were estimated. RESULTS: Galvanized zinc pipes were seriously corroded; there were thin layers on inner face of PPR and ABS plastic pipes. 10 bacterium (got from water samples) were identified by API10S, in which 7 bacterium were opportunistic pathogens. 21 bacterium (got from water and biofilms samples) were identified by API20E, in which 5 bacterium were pathogens and 11 bacterium were opportunistic pathogens and 5 bacteria were not reported for their pathogenicities to human beings. CONCLUSION: The bacterial water quality of drinking water distribution networks were not good. Most bacterium in drinking water and biofilms on the inner face of pipeline of the drinking water distribution network were opportunistic pathogens, it could cause serious water supply accident, if bacteria spread in suitable conditions. In the aspect of pipe material, old pipelines should be changed by new material pipes.