School of Chemical, Biological, and Environmental Engineering, Oregon State University, 103 Gleeson Hall, Corvallis, OR 97331-2702, USA.
School of Chemical, Biological, and Environmental Engineering, Oregon State University, 103 Gleeson Hall, Corvallis, OR 97331-2702, USA.
Water Res. 2012 Nov 1;46(17):5788-5798. doi: 10.1016/j.watres.2012.08.008. Epub 2012 Aug 14.
Low concentrations of dissolved copper have been shown to adversely affect the olfactory system of salmonid species, impairing their ability to avoid predators and likely increasing mortality. These studies have resulted in increased regulatory scrutiny of stormwater discharges to surface waters inhabited by threatened and endangered salmonid species. Because it is primarily the free ionic (Cu(2+)) and weakly complexed forms of copper that are bioavailable, it is critical to understand the speciation of copper in stormwater. This paper reports on the characterization of copper binding ligands and copper speciation in composite samples of highway stormwater runoff collected at four sites in Oregon, USA using competitive ligand exchange - adsorptive cathodic stripping voltammetry (CLE-ACSV). Although the concentration and strength of copper binding ligands in stormwater varied considerable between sites and storms, the vast majority (>99.9%) of the total dissolved copper in composite samples was complexed by organic ligands in stormwater. Although total dissolved copper concentrations range from 2 to 20 μg/L, the analytically determined free ionic copper concentrations did not exceed 10(-10) M (6.3 ng/L) in any of the fully characterized samples, suggesting that much of the copper in highway stormwater is not bioavailable. Analytically determined free ionic copper concentrations were compared with those predicted by a readily available chemical equilibrium models and found to be in reasonable agreement.
低浓度的溶解态铜已被证明会对鲑鱼物种的嗅觉系统产生不利影响，削弱它们逃避捕食者的能力，并可能导致死亡率上升。这些研究导致对受威胁和濒危鲑鱼物种栖息的地表水中雨水排放的监管审查更加严格。由于游离离子（Cu(2+)）和弱配位形式的铜才具有生物可利用性，因此了解雨水铜的形态至关重要。本文报告了使用竞争配位交换 - 吸附阴极溶出伏安法（CLE-ACSV）在美国俄勒冈州四个地点收集的高速公路雨水径流复合样品中铜结合配体的特征描述和铜形态。尽管雨水和风暴之间的雨水铜结合配体的浓度和强度差异很大，但在复合样品中，绝大多数（>99.9%）的总溶解铜与雨水中的有机配体络合。尽管总溶解铜浓度范围为 2 至 20μg/L，但在所有完全特征化的样品中，分析确定的游离离子铜浓度均未超过 10(-10) M（6.3ng/L），这表明高速公路雨水中的大部分铜没有生物可利用性。分析确定的游离离子铜浓度与易于获得的化学平衡模型预测的浓度进行了比较，结果发现两者基本一致。
