路面径流的大肠菌群污染及其雨水花园处理

调查了上海市区路面径流中大肠菌群的污染状况,分析了径流中大肠菌群含量的主要影响因素,采用雨水花园模拟柱,考察雨水花园对城市路面径流中大肠菌群的去除效果。结果表明,上海市区地面道路径流中总大肠菌群、粪大肠菌群的均值分别为2.28×106、9.48×105 cfu/100 mL,污染较严重,径流中大肠菌群含量与气温呈正相关;雨水花园对径流中大肠菌群具有良好的去除效果,不同模拟柱平均去除率范围在92.4%~99.5%。填料深度和水力停留时间是影响雨水花园对大肠菌群去除效果的主要因素。长期运行后,填料中没有大肠菌群的积累,雨水花园对大肠菌群的去除效果可保持长期稳定。

Coliforms in road runoff and its removal by rain gardens

Based on monitoring the number of coliforms in road runoff of Shanghai urban area, the factors affecting the number of coliforms in road runoff were analyzed, further more, rain garden columns were developed to investigate the removal efficiencies of coliforms in road runoff. The results indicated that coliforms pollution of road runoff in Shanghai urban area was serious, and mean counts of total coliforms, fecal coliforms were 2.28×106, 9.48×105cfu/100 mL, respectively. Temperature had a statistically significant positive effect on the number of coliforms in road runoff. Different types of rain garden columns all achieved high removal efficiency of total coliform group, ranging from 92.4% to 99.5%. The depth of media and hydraulic retention time (HRT) of rain garden were important factors on the removal of coliforms in road runoff. Total coliforms had no significant increase in column media after application. Rain garden has significant potential for application for removal of coliform bacteria in urban stormwater runoff.