Transport and fate of fluorinated DNAPL in a surficial clay aquitard

加拿大各地有成千上万个受污染的场地，对人类健康和/或生态构成潜在风险，清理这些场地需要承担巨大的经济责任。了解控制污染物运输和命运的过程对于评估这些风险和在现场管理和补救方面做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分辨率，因此缺乏对影响或风险的可靠估计。了解控制过程的另一个障碍是，大多数地点污染物释放的性质和时间非常不确定。拟议的研究涉及1982年因火车脱轨而发生的大量氟化致密非水相液体（DNAPL）（4-氯苯三氟）释放到浅层粘土水道中，因此释放的位置、时间和体积是非常确定的。因此，该地点提供了一个独特的机会来研究“老化”的DNAPL泄漏的演变，该泄漏已经演变了30多年，以及其质量和相位分布、流动性和命运的长期演变。调查将采用先进的高分辨率方法进行，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