百年一遇大旱后城区降雨径流中重金属与悬浮物相关性分析

Correlations Analysis among Heavy Metals and Suspended Solids in Precipitation Runoff of Urban Area after the Once-in-a-century Drought

为了探讨2009年入秋至2010年春,西南百年一遇大旱后城市降雨径流中重金属污染特性,对昆明市交通干道路面及路旁一处混凝土屋面的3次降雨径流进行了监测,研究了城区降雨径流中Cu、Zn、Cd、Pb、Fe、Mn、Cr的变化过程,分析了不同重金属之间、重金属与悬浮物(SS)之间的相关性。3次降雨径流中重金属质量浓度随降雨呈不同程度下降。大旱后的首次降雨径流重金属污染最严重,次日的降雨径流重金属污染最轻。降雨径流中各重金属均与SS在含量上明显相关,径流中的重金属主要以吸附在SS上的不溶态存在。屋面与路面径流中的大多数重金属具有良好的同源性。

To probe into heavy metal pollution characteristics of urban precipitation runoff after the once-in-a-century drought in Southwest China from the autumn of 2009 to the spring of 2010,the process variation of Cu,Zn,Cd,Pb,Fe,Mn and Cr in urban precipitation runoff in Kunming had been analyzed according to correlations among the heavy metals and suspended solids in precipitation runoff.It was found that the concentrations of heavy metals in the three precipitation runoff processes decreased with the rainfall time.The top pollution of heavy metals happened in the first runoff and the light pollution on the next day.There were significant correlations between each heavy metal and suspended solids in the runoff.The heavy metals were adsorbed on suspension solids and existed in insoluble forms.The heavy metals in runoff on roof and road surface came obviously from a same source.