Poté John, Goldscheider Nico, Haller Laurence, Zopfi Jakob, Khajehnouri Fereidoun, Wildi Walter
Forel Institute, University of Geneva, 10 Route de Suisse, PO Box 416, 1290 Versoix, Switzerland.
Environ Monit Assess. 2009 Jul;154(1-4):337-48. doi: 10.1007/s10661-008-0401-8. Epub 2008 Jun 19.
The origin and distribution of microbial contamination in Lake Geneva's most polluted bay were assessed using faecal indicator bacteria (FIB). The lake is used as drinking water, for recreation and fishing. During 1 year, water samples were taken at 23 points in the bay and three contamination sources: a wastewater treatment plant (WWTP), a river and a storm water outlet. Analyses included Escherichia coli, enterococci (ENT), total coliforms (TC), and heterotrophic plate counts (HPC). E. coli input flux rates from the WWTP can reach 2.5 x 10(10) CFU/s; those from the river are one to three orders of magnitude lower. Different pathogenic Salmonella serotypes were identified in water from these sources. FIB levels in the bay are highly variable. Results demonstrate that (1) the WWTP outlet at 30 m depth impacts near-surface water quality during holomixis in winter; (2) when the lake is stratified, the effluent water is generally trapped below the thermocline; (3) during major floods, upwelling across the thermocline may occur; (4) the river permanently contributes to contamination, mainly near the river mouth and during floods, when the storm water outlet contributes additionally; (5) the lowest FIB levels in the near-surface water occur during low-flow periods in the bathing season.
利用粪便指示菌（FIB）评估了日内瓦湖污染最严重海湾中微生物污染的来源和分布。该湖被用作饮用水源、娱乐用水和渔业用水。在一年时间里，在该海湾的23个点位以及三个污染源（一座污水处理厂、一条河流和一个雨水排放口）采集了水样。分析项目包括大肠杆菌、肠球菌（ENT）、总大肠菌群（TC）和异养平板计数（HPC）。污水处理厂的大肠杆菌输入通量率可达2.5×10¹⁰CFU/秒；河流的通量率则低一至三个数量级。在这些来源的水体中鉴定出了不同的致病性沙门氏菌血清型。该海湾中的FIB水平变化很大。结果表明：（1）冬季全混合期时，30米深处的污水处理厂排放口会影响近地表水水质；（2）湖泊分层时，排放的水通常被困在温跃层以下；（3）在大洪水期间，可能会出现跨越温跃层的上升流；（4）河流持续造成污染，主要在河口附近以及洪水期间，此时雨水排放口会额外造成污染；（5）近地表水的FIB水平在游泳季节的低流量期最低。
