Stormwater best management practices: Experimental evaluation of chemical cocktails mobilized by freshwater salinization syndrome
Stormwater best management practices: Experimental evaluation of chemical cocktails mobilized by freshwater salinization syndrome
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DOI：
10.3389/fenvs.2023.1020914
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发表时间：
2023-04
影响因子：
8.7
通讯作者：
J. Galella;S. Kaushal;P. Mayer;C. Maas;Ruth R. Shatkay;Robert A. Stutzke
中科院分区：
文献类型：
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作者：
J. Galella;S. Kaushal;P. Mayer;C. Maas;Ruth R. Shatkay;Robert A. Stutzke
淡水盐化综合症（FSS）是指盐离子对自然、工程和社会系统退化产生的一系列物理、生物和化学影响。 FSS 对化学混合物调动的影响已在溪流和地下水中得到记录，但很少有研究关注 FSS 对雨水最佳管理实践 (BMP) 的影响，例如：人工湿地、生物洼地、池塘和生物滞留。然而，新兴研究表明，雨水最佳管理措施可能既是污染物的来源，又是污染物的汇，并随着道路盐的施用而季节性变化。我们进行了实验室实验来研究这个前提；从四种不同的雨水特征类型（生物滞留、生物沼泽、人工湿地和滞留池）收集重复的水和土壤样本，并用于在六种不同盐度下使用三种不同盐（NaCl、CaCl2 和 MgCl2）进行的盐孵化实验。盐浓度的增加对主要元素和微量元素的迁移产生了深远的影响，所有三种盐在几乎所有分析的元素中都显示出显着的正相关关系。在所有地点，Na+、Mg2+ 和 Ca2+ 的平均盐保留分别为 34%、28% 和 26%，并且雨水 BMP 之间存在显着差异。盐型显示出某些元素的优先动员。氯化钠动员铜（一种对水生生物群的强毒物）的速率比氯化钙和氯化镁高一个数量级。雨水 BMP 类型也对元素动员有显着影响，池塘动员的锰明显多于其他地点。然而，盐浓度和盐类型始终对所有雨水 BMP 中动员的元素的平均浓度有显着影响 (p < 0.05)，这表明离子交换等过程会动员金属，而无论 BMP 类型如何。我们的结果表明，有关用作除冰剂的盐的数量和类型的决定可以对减少污染物迁移到淡水生态系统产生重大影响。
Freshwater Salinization Syndrome (FSS) refers to the suite of physical, biological, and chemical impacts of salt ions on the degradation of natural, engineered, and social systems. Impacts of FSS on mobilization of chemical cocktails has been documented in streams and groundwater, but little research has focused on the effects of FSS on stormwater best management practices (BMPs) such as: constructed wetlands, bioswales, ponds, and bioretention. However emerging research suggests that stormwater BMPs may be both sources and sinks of contaminants, shifting seasonally with road salt applications. We conducted lab experiments to investigate this premise; replicate water and soil samples were collected from four distinct stormwater feature types (bioretention, bioswale, constructed wetlands and retention ponds) and were used in salt incubation experiments conducted under six different salinities with three different salts (NaCl, CaCl2, and MgCl2). Increased salt concentrations had profound effects on major and trace element mobilization, with all three salts showing significant positive relationships across nearly all elements analyzed. Across all sites, mean salt retention was 34%, 28%, and 26% for Na+, Mg2+ and Ca2+ respectively, and there were significant differences among stormwater BMPs. Salt type showed preferential mobilization of certain elements. NaCl mobilized Cu, a potent toxicant to aquatic biota, at rates over an order of magnitude greater than both CaCl2 and MgCl2. Stormwater BMP type also had a significant effect on elemental mobilization, with ponds mobilizing significantly more Mn than other sites. However, salt concentration and salt type consistently had significant effects on mean concentrations of elements mobilized across all stormwater BMPs (p < 0.05), suggesting that processes such as ion exchange mobilize metals mobilize metals and salt ions regardless of BMP type. Our results suggest that decisions regarding the amounts and types of salts used as deicers can have significant effects on reducing contaminant mobilization to freshwater ecosystems.