基于水质水量监测的武汉市雨水径流污染特征分析

Analysis of Pollution Characteristics of Rainwater Runoff in Wuhan City Based on Water Quality and Quantity Monitoring

以武汉市茶山刘分流制排水区域为例,基于4场雨水径流水质水量监测资料,采用初始冲刷无量纲累积分析M(V)曲线分析了雨水径流初始冲刷效应,并使用SPSS软件对4场降雨事件的水质指标进行相关性分析。结果表明,武汉市雨水径流污染物COD、TP、TN、NH_(3)-N的降雨径流平均浓度分别为地表水Ⅴ类标准的4.9、6.2、13.0、9.7倍,雨水径流污染负荷较高;降雨强度和前期干旱天数是影响初始冲刷效应的主要因素,截流前40%~60%的径流量可截流大部分污染物;降雨强度不大时,雨水径流中SS与COD、TP、TN有较强的相关性;降雨达到暴雨级别时,雨水径流中SS仅与COD呈现相关性;降雨强度不大的降雨事件,可通过去除SS来削减雨水径流污染物量;对于暴雨时的雨水径流,通过去除SS削减污染物量的效果不显著。

Taking the separated drainage area of Chashanliu in Wuhan City as an example,based on the water quality and quantity monitoring data of four rainwater runoff,M(V)curve was used to analyze initial erosion effect.The software SPSS was used to analyze the correlation of water quality indexes for four rainfall events.The results show that the EMC of the concentration of pollutants COD,TP,TN,NH_(3)-N in the rainwater runoff were 4.9、6.2、13.0 and 9.7 times of the surface water class V standard.Rainwater runoff had a high pollution load.The rainfall intensity and previous dry days were the main factors affecting the initial erosion effect.The first 40%-60% of the runoff volume carried most part of the pollutants.The SS in the rainwater runoff had a strong correlation with the COD,TP and TN when the rainfall intensity was smaller.The SS in the rainwater runoff only showed the correlation with the COD when the rainfall intensity reached the rainstorm level.The amount of pollutants in rainwater runoff could be cut down effectively by removing SS when the rainfall intensity was low.Removing SS had no significant effect to cut down the amount of pollutants in rainwater runoff of heavy rains.