Thermally Enhanced Remediation of Groundwater Contamination

石油碳氢化合物和氯化溶剂对地下水的污染严重威胁着人类和生态系统的健康。积极的热修复方法，如导热加热、电阻加热和蒸汽冲洗，对相对均匀土壤中的挥发性有机物是有效的。然而，这些方法技术复杂，成本昂贵，在更多的地下系统中，对于挥发性较低的有机物，复杂性和成本大幅增加。对于小型网站来说，这些技术按每卷一美元计算的成本特别高。*化学氧化和就地生物修复已在加拿大和全球受污染的地点广泛实施。在环境地下温度下，特别是在加拿大，这些工艺去除污染物的速度可能相当慢。通过热空气冲洗、热水冲洗或电加热将温度适度提高30至40摄氏度，可能会以适度的成本和技术复杂性显著改进这些补救方法。*拟议研究计划的长期目标是开发和优化基于热强化、耦合技术和替代能源的更可持续的地下水修复方法。短期目标是研究嗜热菌在热强化生物修复中的作用，并确定在硫酸盐还原条件下热激活过硫酸盐氧化与生物修复相结合的有效性。这项研究将包括在柱子和二维储罐中进行实验室研究，这些储罐充斥着不均匀的土壤以及来自行业合作伙伴现场的地下水和土壤。通过将温度、地化和微生物群落变化与修复结果联系起来的统一方法，将有可能为热强化生物修复的现场规模设计提供迫切需要的新指南。将开发一个全面的模拟模型，作为工业界设计现场规模的热强化补救方案的工具。将从成本、复杂性和碳足迹方面研究其他更可持续的取暖方法，包括太阳能电加热方法、太阳能热水加热方法和工业废热回收。*这项研究将极大地促进对热量对加强地下补救过程的影响的理解。由于这些过程中的不确定性目前是其实施的障碍，这将导致更广泛地应用热法，从而有效地清理更多的地点。这将通过改善对地下水的保护而使加拿大人受益。通过出版物、会议演讲和研究生培训将知识转移到加拿大公司，将为这些公司带来更多的商业机会。

Groundwater contamination by petroleum hydrocarbons and chlorinated solvents is a serious threat to human and ecosystem health. Aggressive thermal remediation methods such as thermal conductive heating, electrical resistance heating, and steam flushing are effective for volatile organics in relatively homogeneous soils. However, these methods are technologically complex and expensive with complexity and cost increasing substantially for less volatile organics in more heterogeneous subsurface systems. The costs of these technologies on a dollar per volume basis are particularly high for small sites. ******Chemical oxidation and in situ bioremediation have been widely implemented at contaminated sites in Canada and globally. At ambient subsurface temperatures, particularly in Canada, the rates of contaminant removal by these processes may be quite slow. Moderately increasing temperatures by 30 to 40 oC through hot air flushing, hot water flushing, or electrical heating may lead to significant enhancement of these remediation methods at modest cost and technical complexity. ******The long term objective of the proposed research program is to develop and optimize more sustainable groundwater remediation methods based on thermal enhancements, coupled technologies, and alternative energy sources. The short term objectives are to investigate the role of thermophiles in thermally enhanced bioremediation and to determine the effectiveness of thermally activated persulfate oxidation coupled to bioremediation under sulfate reducing conditions. The research will involve lab studies in columns and two-dimensional tanks packed with heterogeneous soils and groundwater and soil from industry partner field sites. With a unified approach of relating temperature, geochemistry, and microbial community changes to remediation outcomes, new much needed guidelines for field scale design of thermally enhanced bioremediation will be possible. A comprehensive simulation model will be developed as a tool for industry to design field scale thermally enhanced remediation schemes. Alternative more sustainable methods of heating will be investigated with respect to cost, complexity, and carbon footprint, including solar electric heating methods, solar water heating, and industrial waste heat recovery. ******This research will significantly advance the understanding of the impact of heat on enhancement of subsurface remediation processes. As the uncertainty in these processes is currently a barrier to their implementation this will lead to more widespread application of thermal methods, resulting in effective cleanup of more sites. This will benefit Canadians through improved protection of groundwater. Transfer of the knowledge to Canadian companies through publications, conference addresses, and training of graduate students will lead to increased business opportunities for these companies.**