Université de Lorraine, CNRS, LIEC, F-54000, Nancy, France.
GeoRessources lab, Université de Lorraine, CNRS, CREGU, F-54000, Nancy, France.
Environ Sci Pollut Res Int. 2019 Jan;26(2):1693-1705. doi: 10.1007/s11356-018-3708-1. Epub 2018 Nov 17.
In industrial sites, historically contaminated by coal tar (abandoned coking and manufactured gas plants), other families of organic pollutants than the 16 PAHs (polycyclic aromatic hydrocarbons) classified by the US-EPA can occur and induce potential risk for groundwater resources. Polar PACs (polycyclic aromatic compounds), especially oxygenated and nitrogenated PACs (O-PACs and N-PACs), are present in the initial pollution and can also be generated over time (i.e., O-PACs). Their aqueous solubilities are much greater than those of the PAHs. For these reasons, we need to increase our knowledge on polar PACs in order to better predict their behavior and the potential on-site risk. Batch leaching tests were carried out under various conditions of temperature, ionic strength, and availability of pollutants to determine the mechanisms and key parameters controlling their release. The results show a release of low-molecular-weight PAHs and polar PACs mainly by dissolution, while higher molecular weight PAHs are mainly released in association with colloids. Aging mainly controls the former mechanism, and ionic strength mainly controls the latter. Temperature increased both dissolution and colloidal mobilization. The Raoult law predicts the PAC equilibrium concentration for soils presenting high pollutant availability, but this law overestimates PAC concentration in aged soils (low pollutant availability). This is mainly due to limitation of PAC diffusion within coal-tar particles with aging. The most soluble PACs (especially polar PACs) are the most sensitive to aging. For better prediction of the PAC behavior in soils and water resources management, aging needs to be taken into account.
在工业场地中，历史上受到煤焦油污染（废弃的炼焦和人工煤气厂），除了美国环保署（US-EPA）分类的 16 种多环芳烃（PAHs）外，还可能存在其他有机污染物家族，这可能会对地下水资源造成潜在风险。极性 PAHs（多环芳烃化合物），特别是含氧和含氮的 PAHs（O-PACs 和 N-PACs），存在于初始污染中，并且随着时间的推移也会产生（即 O-PACs）。它们的水溶解度比 PAHs 大得多。出于这些原因，我们需要增加对极性 PAHs 的了解，以便更好地预测它们的行为和潜在的现场风险。进行了批式浸出试验，在不同的温度、离子强度和污染物可利用性条件下进行，以确定控制其释放的机制和关键参数。结果表明，低分子量 PAHs 和极性 PAHs 主要通过溶解释放，而高分子量 PAHs 主要与胶体一起释放。老化主要控制前一种机制，而离子强度主要控制后一种机制。温度升高了溶解和胶体的迁移。拉乌尔定律预测了高污染物可利用性土壤中 PAH 的平衡浓度，但该定律高估了老化土壤（低污染物可利用性）中 PAH 的浓度。这主要是由于老化过程中 PAC 在煤焦油颗粒内扩散受限。最易溶解的 PAHs（特别是极性 PAHs）对老化最敏感。为了更好地预测 PAHs 在土壤和水资源管理中的行为，需要考虑老化。
