Fate of contaminants in groundwater and development of passive remediation systems

遗留的人类活动释放的污染物已导致加拿大和世界各地许多地方的地下水、土壤和沉积物受到大规模污染。例如，采矿和制造活动导致有毒元素的释放，包括As、Cd、Co、Cu、Mo、Ni、Pb、Hg、Zn和V，这些元素现已造成水质退化或在来源地区下游的土壤和沉积物中积累。由于污染的规模，需要采取昂贵的控制措施，以尽量减少供水和受影响生态系统的进一步退化。在过去几十年中，已经制定了一些补救地下水、沉积物和土壤的办法，并取得了进展。就地补救技术一般适用于规模小于几平方公里的受污染场地。由于场地准入的限制和试剂的高成本，在更大规模上实施补救方法带来了更大的挑战。 我最近的研究活动集中在确定低成本的方法，稳定污染物，可以应用在流域规模。我们正在开展的项目包括：1）了解汞的循环和动态流域中汞甲基化的控制过程，2）了解地表水、废水和地下水中新出现的污染物（包括爆炸物、药物化合物、人工甜味剂和全氟化合物）的命运，3）了解Cr、Se、Cu、Cu、Cr、Se和Se的稳定同位素的分馏，Zn和Ni作为描述反应机理和反应进程的工具。我们评估了稳定或处理地下水、废物和土壤中污染物的新方法。我利用一系列的仪器，包括痕量汞分析仪，自动甲基汞分析仪，离子色谱仪，气相色谱仪，和一个新的高效液相色谱仪/电喷雾三重四极杆质谱仪。通过合作，我还可以使用多收集器电感耦合等离子体质谱仪。我们已经应用了新的同步加速器技术，以进一步了解反应机理。 在接下来的五年里，我计划加快我的研究活动，以评估可适用于大规模污染场地的补救策略。我将进行实验室研究，以评估应用活性介质作为共混试剂，以稳定污染土壤和沉积物中的金属。我将研究地下新出现的污染物的命运，并确定可持续的处理方法。我将继续开发新的工具来描述补救系统的有效性。总的目标是以切实可行、成本效益高和技术上合理的方式努力改善环境。

The release of contaminants from legacy anthropogenic activities has resulted in large-scale contamination of groundwater, soils and sediments at many locations in Canada and around the world. As an example, mining and manufacturing activities have led to the release of toxic elements, including As, Cd, Co, Cu, Mo, Ni, Pb, Hg, Zn, and V that have now caused degradation of water quality or have accumulated in soils and sediments downstream from source areas. Due to the scale of the contamination, costly controls are required to minimize further degradation of water supplies and affected ecosystems. A number of approaches have been developed for remediating groundwater, sediment and soils and advances have been made over the past several decades. In situ remediation techniques are generally applied at contaminated sites that are less than several km2 in scale. Implementing remediation approaches at larger scales presents greater challenges due to limitations to site access and high costs for reagents. My recent research acitivities have focused on identifying low cost approaches for stabilizing contaminants that can be applied at the watershed scale. Projects we are conducting include studies to 1) understand the cycling of Hg and processes controlling Hg methylation in a dynamic watershed, 2) understand the fate of emerging contaminants, including explosives, pharmaceutical compounds, artificial sweeteners, and perfluorinated compounds in surface water, wastewater and groundwater, and 3) understand the fractionation of stable isotopes of Cr, Se, Cu, Zn and Ni as tools for delineating reaction mechanisms and reaction progress. We have evaluated new methods for stabilizing or treating contaminants in groundwater, waste materials and soils. I utilize a series of instruments, including a trace Hg analyzer, an automated methyl Hg analyzer, and ion chromatographs, a gas chromatograph, and a new high-performance liquid chromatograph/electrospray triple quadrupole mass spectrometer. I also have access to a multi-collector inductively coupled plasma mass spectrometer through collaboration. We have applied novel synchrotron techniques to further understand reaction mechanisms. During the next five years, I plan to accelerate my research activities to assess remediation strategies that can be applied to large-scale contaminated sites. I will conduct laboratory studies to evaluate the application of reactive media as co-blending reagents to stabilize metals in contaminated soils and sediments. I will study the fate of emerging contaminants in the subsurface and identify sustainable treatment approaches. I will continue to develop novel tools to characterize the effectiveness of remediation systems. The overall goal is to work towards improving the environment in a practical, cost-effective and technically sound manner.