Institute of Mining and Special Civil Engineering, Technical University Mining Academy, Gustav-Zeuner Street 1A, Freiberg, 09599, Germany.
U.S. Environmental Protection Agency, Office of Research and Development, Center for Environmental Measurement and Modeling, Atlantic Coastal Environmental Sciences Division, 27 Tarzwell Drive, Narragansett, Rhode Island 02882, USA.
Environ Sci Process Impacts. 2024 Nov 13;26(11):2076-2089. doi: 10.1039/d4em00133h.
In equilibrium-based passive sampling applications, the accuracy of estimating freely dissolved concentration () of hydrophobic organic compounds (HOCs) relies on the passive sampler-water partition coefficient () values applied. The vast majority of are generated under standard conditions: 20 °C in deionized or freshwater. Few empirically derived values are available for non-standard conditions. In this study, polyethylene (PE)-water partitioning coefficients () were experimentally determined for 15 polycyclic aromatic hydrocarbons (PAHs, comprising 9 parent and 6 alkylated compounds) under three different temperature (10, 20, 30 °C) and salinity (0, 18 and 36‰) regimes, the values were found to correlate strongly with a variety of molecular parameters (, octanol-water partition coefficients (), molecular weight (MW) and molecular volume ()). The effects of temperature and salinity on the magnitude of were found to be substantial. For temperature, the values range between -0.005 and -0.023 log units per °C; these values indicate that every 10 °C rise in temperature would potentially decrease the by a factor of between 0.4 to 1.6. For salinity, the values range from 0.0028 to 0.0057 log units per unit ‰, indicating that an 18‰ increase in salinity would likely increase the by a factor of between 0.28 and 0.82. Moreover, temperature and salinity were shown to be independent of each other and non-interacting. Temperature effects were chemical-specific and moderately dependent on hydrophobicity (expressed as the ), whereas salinity effects were independent of hydrophobicity. We also assessed the combined impact of temperature and salinity, which showed increasing effects with the hydrophobicity of the PAHs studied. Based on the results, values adjusted for site-specific temperature and salinity can be calculated. The impact of applying such site-specific values was demonstrated using a PE-based field monitoring dataset for PAHs from coastal waters of Grand Isle (LA, USA) collected during the 2010 Deepwater Horizon oil spill. When values were adjusted to 10 °C and 30 °C, the final freely dissolved concentrations () decreased or increased depending on the adjustment. Use of the results of this investigation allow for adjusting existing PE-based datasets to site-specific conditions resulting in more accurate values for estimating exposure and adverse ecological effects.
在基于平衡的被动采样应用中，估计疏水性有机化合物（HOC）自由溶解浓度（）的准确性取决于所应用的被动采样器-水分配系数（）值。绝大多数值是在标准条件下产生的：20°C 去离子水或淡水。很少有经验得出的值可用于非标准条件。在这项研究中，实验确定了 15 种多环芳烃（PAH，包括 9 种母体和 6 种烷基化化合物）在三种不同温度（10、20 和 30°C）和盐度（0、18 和 36‰）下的聚乙烯（PE）-水分配系数（），发现值与多种分子参数（、辛醇-水分配系数（）、分子量（MW）和分子体积（））密切相关。温度和盐度对值大小的影响很大。对于温度，值范围在 -0.005 到-0.023 每°C 的对数单位之间；这些值表明，温度每升高 10°C，可能会使降低 0.4 到 1.6 倍。对于盐度，值范围从 0.0028 到 0.0057 每单位‰的对数单位，表明盐度增加 18‰可能会使增加 0.28 到 0.82 倍。此外，温度和盐度被证明是相互独立的，并且没有相互作用。温度影响是特定于化学物质的，并且与疏水性（用表示）中度相关，而盐度影响与疏水性无关。我们还评估了温度和盐度的综合影响，结果表明，研究的 PAH 的疏水性越大，影响越大。基于结果，可以计算出针对特定地点的温度和盐度调整后的值。通过使用来自美国路易斯安那州格兰德艾尔岛（Grand Isle）沿海地区的 2010 年深海地平线（Deepwater Horizon）石油泄漏期间收集的基于 PE 的现场监测数据集来证明应用这种特定地点值的影响。当值调整为 10°C 和 30°C 时，最终的自由溶解浓度（）会根据调整而降低或升高。使用本研究的结果可以调整现有的基于 PE 的数据集以适应特定地点的条件，从而为估计暴露和不利生态影响提供更准确的值。
