南京市梅雨期雨水水质特性分析

Analysis on Rainwater Quality of Rainy Season in Nanjing

为了解南京市梅雨季节降雨在不同下垫面类型水质变化状况和污染特性,于2016年6月-7月进行5场雨水径流水质的监测,分别对其pH、悬浮物、色度和重金属含量进行分析。结果表明:(1)南京市梅雨期天然降水以中性为主;瓦屋面和油毡屋面降水质呈酸性,而水泥屋面则为呈碱性,在路面径流中均呈酸性。(2)路面雨水径流中固体悬浮物(SS)含量均显著高于天然雨水和屋面雨水。(3)路面雨水由黑褐色最终变为浅黄色;油毡屋面,由黄色最终变为浅黄色;路面雨水的色度远大于屋面雨水色度。(4)降雨中Mn、Zn、Pb、Cd、Fe均出现超标现象,重金属污染先后顺序为:交通区机动车道>住宅区机动车道>屋面(油毡)>屋面(瓦房)>天然降雨。研究结论对南京市梅雨季节雨水中重金属污染评价及污染治理等提供了理论参考。

In order to understand rainfall water quality change of and pollution characteristics in different types of underlying sur-face condition in plum rains season in Nanjing, 5 times evolution process of rainfall water quality were monitored and analyzed in the aspects of pH、SS、chroma、heavy metal contents from June to July in 2016. The research results showed the water quality of natural precipitation mainly presented neutrality in plum rains season in Nanjing. The runoff on the roof and linoleum presented acid, the run-off water on cement roof was alkalineand the water of road runoff was acidic. SS in the road runoff was obiviouly higher than that of the natural rain and on the roof. The water color of road runoff changed from dark brown into pale yellow eventually. The water color of roof became to be a light yellow from yellow eventually. The water chroma of road runoff was heavier than that of roof runoff. The con-tent of Mn, Zn, Pb, Cd and Fe in rainfall all exceed standards. The pollution of heavy metal elementswas in the following orderroad traffic area of motor vehicle 〉 residential area of motor vehicle 〉 the roof（ linoleum） 〉 the roof（ tile） 〉 natural rainfall. The research and evaluation of heavy metal pollution in plum rains season in Nanjing provides a theoretical basis for pollution control.