生物滞留池对雨水径流中污染物的净化效果

Removal of Contaminants from Stormwater Runoff through Bioretention

采用砂壤土作为生物滞留装置的填料,进行了模拟人工降雨试验,配制雨水中的污染物浓度分为低、中、高3种梯度,研究其对雨水径流的净化效果。结果表明,只有当雨水径流中特定污染物浓度达到一定的值,生物滞留池才会对该特定污染物有明显净化效果,否则出水中特定污染物浓度变化不大,甚至反而会有所增加。生物滞留池出水中的COD、TP、TN以SCOD、DTP和DTN为主。生物滞留池对污染物去除率的大小排序为COD>TP>TN。

Bioretention is frequently used as a LID facility for removing pollutants from stormwater runoff and controlling nonpoint source pollution.We analyzed the water quality purification effect of bioretention by using sandy loam as the medium.Runoff events were simulated,and inflow concentrations of contaminants were preset in three levels.The exoerimental results show that the bioretention will exhibit evident purification effects only when the concentration of specific pollutants in stormwater runoff reaches a certain value.Otherwise,the concentration will be unchanged or even increase.The COD,TP,and TN in effluent are mainly SCOD,DTP,and DTN,correspondingly.The size of the removal rate of pollutants is sorted by COD>TP>TN.