Department of Civil and Environmental Engineering , Colorado School of Mines , Golden , Colorado 80401 , United States.
Department of Environmental Chemistry , Eawag, Swiss Federal Institute of Aquatic Science and Technology , 8600 Dübendorf , Switzerland.
Environ Sci Technol. 2019 Apr 2;53(7):3634-3644. doi: 10.1021/acs.est.8b05833. Epub 2019 Mar 22.
Urban-use pesticides are of increasing concern as they are widely used and have been linked to toxicity of aquatic organisms. To assess the occurrence and treatment of these pesticides in stormwater runoff, an approach combining field sampling and watershed-scale modeling was employed. Stormwater samples were collected at four locations in the lower San Diego River watershed during a storm event and analyzed for fipronil, three of its degradation products, and eight pyrethroids. All 12 compounds were detected with frequency ranging from 50 to 100%. Field results indicate pesticide pollution is ubiquitous at levels above toxicity benchmarks and that runoff may be a major pollutant source to urban surface waters. A watershed-scale stormwater model was developed, calibrated using collected data, and evaluated for pesticide storm load and concentrations under several management scenarios. Modeling results show that enhanced stormwater control measures, such as biochar-amended biofilters, reduce both pesticide storm load and toxicity benchmark exceedances, while conventional biofilters reduce the storm load but provide minimal toxicity benchmark exceedance reduction. Consequently, biochar amendment has the potential to broadly improve water quality at the watershed scale, particularly when meeting concentration-based metrics such as toxicity benchmarks. This research motivates future work to demonstrate the reliability of full-scale enhanced stormwater control measures to treat pollutants of emerging concern.
城市用农药的使用越来越受到关注，因为它们广泛使用，并与水生生物的毒性有关。为了评估这些农药在雨水径流中的出现和处理情况，采用了一种结合现场采样和流域尺度建模的方法。在圣迭戈河下游流域的四个地点，在一次风暴事件中收集了雨水样本，并对氟虫腈、其三种降解产物和八种拟除虫菊酯进行了分析。所有 12 种化合物均被检测到，频率范围为 50%至 100%。现场结果表明，农药污染普遍存在，且水平高于毒性基准，径流可能是城市地表水污染的主要污染源。开发了一个流域尺度的雨水模型，使用收集的数据进行了校准，并在几种管理情景下评估了农药雨水负荷和浓度。模拟结果表明，增强雨水控制措施，如生物炭改良生物过滤器，可以减少农药雨水负荷和毒性基准超标，而传统生物过滤器则减少了雨水负荷，但对毒性基准超标减少的作用有限。因此，生物炭改良有可能在流域尺度上广泛改善水质，特别是在满足基于浓度的指标（如毒性基准）时。这项研究激发了未来的工作，以证明全尺度增强雨水控制措施处理新兴关注污染物的可靠性。
