Transport and fate of fluorinated DNAPL in a surficial clay aquitard

加拿大各地有数以万计的受污染地点，它们对人类健康和/或生态构成潜在风险，并为清理这些地点承担着巨大的经济责任。了解控制污染物迁移和去向的过程对于评估这些风险并就场地管理和补救作出明智的决定是必要的。然而，传统的现场调查方法通常缺乏基于过程的理解所需的解决方案，因此无法可靠地估计影响或风险。理解控制过程的另一个障碍是，大多数地点污染物排放的性质和时间非常不确定。拟议的研究涉及1982年由于火车脱轨而发生的大量氟化稠密非水相液体(4-氯苯三氟)释放到地面粘土蓄水层中，因此可以很确定地知道释放的地点、时间和体积。因此，这一地点提供了一个独特的机会来研究三十多年来“陈旧”的DNAPL泄漏的演化，以及它在质量和相分布、流动性和命运方面的长期演化。将使用先进的高分辨率方法进行调查，重点是

There are tens of thousands of contaminated sites across Canada which pose potential human health and /or ecological risks and carry immense financial liabilities for their cleanup. Understanding the processes controlling contaminant transport and fate is necessary for assessing these risks and making informed decisions on site management and remediation. However conventional site investigation approaches generally lack resolution required for process-based understanding and therefore, reliable estimation of impacts or risks. Another impediment to understanding controlling processes is that the nature and timing of contaminant releases at most sites is very uncertain. The proposed study involves a release of a large volume of a fluorinated dense non-aqueous phase liquid (DNAPL) (4- chlorobenzotrifluoride) that occurred in 1982 into a surficial clayey aquitard as a result of a train derailment, such that the location, timing and volume of the release is known with good certainty. Therefore this site offers a unique opportunity to study evolution of an "aged" DNAPL spill that has evolved over three decades and its long-term evolution of mass and phase distribution, mobility and fate. Investigations will be conducted using advanced high resolution methods focused on the