Mercury mobilization in urban stormwater runoff
Mercury mobilization in urban stormwater runoff
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DOI：
10.1016/j.scitotenv.2008.05.021
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发表时间：
2008-09-15
影响因子：
9.8
通讯作者：
Branfireun, Brian
中科院分区：
文献类型：
--
作者：
Eckley, Chris S.;Branfireun, Brian
城市雨水径流已被确定为许多污染物的水道损害的主要原因，但一直缺乏直接测量城市雨水径流中汞的研究。本研究的目标是：使用高频采样来描述单个降雨事件期间城市微流域(即停车场)的汞输出动态；确定悬浮泥沙与汞迁移之间的关系；收集事件尺度下大气汞输入、地表储存和径流中汞输出的质量平衡，以评估降雨来源的汞和地表来源的汞在径流中的相对重要性；最后，将城市微流域的汞产生量与更大的混合土地利用的城市集水区的汞产生量进行比较，以评估结果的可行性。结果表明，径流中汞浓度最高出现在过程线上升段(一次冲刷效应)，以颗粒结合态汞为主(84+/-8%)。径流中汞浓度与总悬浮固体(TSS)浓度之间存在显著的相关性。在所有事件中，最大的汞通量发生在峰值放电期间，尽管这一时期的汞浓度明显较低。集水区表面汞负荷(即街道灰尘)在研究过程中有所不同，但变化与降雨事件没有明显联系。从汇水区输入和输出的汞的质量平衡表明，它可以作为汞的汇或源，这取决于降雨特征。较大的混合土地覆盖集水区的汞出口都在停车场集水区的值范围内，但由于流域内的滞留量增加和来源/干扰较少，往往较低。(C)2008爱思唯尔B.V.保留所有权利。
Urban stormwater runoff has been identified as a leading cause of waterway impairment for many pollutants, but there has been a lack of research that directly measures Hg in urban stormwater runoff. The objectives of this research were: to use high frequency sampling to characterize the Hg export dynamics from an urban micro-catchment (i.e. a parking lot) during individual rain events; determine the relationship between suspended sediments and Hg transport; assemble event-scale mass balances of atmospheric Hg inputs, surface storage, and Hg export in runoff to evaluate the relative importance of rainfall-derived Hg and surface-derived Hg in runoff; and finally, to compare the yield of Hg from the urban micro-catchment to that of a larger mixed land-use urban catchment to evaluate the feasibility of scaling the results. The results found that the highest Hg concentrations in runoff were observed during the rising limb of the hydrograph (first flush effect), which was dominated by particulate bound Hg (84 +/- 8%). There was a significant relationship between the Hg and total suspended solids (TSS) concentrations in runoff. For all events, the largest Hg flux occurred during the period of peak discharge, even though the Hg concentrations were substantially lower during this period. The catchment surface Hg load (i.e. street dust) varied over the course of the study, but the changes were not clearly linked to the rain events. The mass balance of the Hg inputs and outputs from the catchment showed that it could act as a Hg sink or a source depending on the rainfall characteristics. The export of Hg from the larger mixed land-cover catchment were all within the range of the values from the parking-lot catchment, though tended to be lower as a result of increased retention and fewer sources/disturbance within the catchment. (C) 2008 Elsevier B.V. All rights reserved.