Remediation in Challenging Environments: A New Approach for Accelerating Bioremediation in Cold Climates

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In Canada, the Federal Contaminated Sites Inventory lists more than 21,000 sites that are contaminated or suspected of being contaminated. In about 80% of the total number of contaminated sites, it is the soil environments, including surface and subsurface soils, sediments and groundwater, which are contaminated. The most frequently identified contaminants at these sites are petroleum hydrocarbons, which are non-aqueous phase liquids that include toxic and carcinogenic organic compounds. **In many of the contaminated sites in Canada, hydrocarbon contamination exists in cold-climate soil environments. The ground in cold regions remains semi-frozen and frozen for 6 to 9 months of the year, which greatly shortens the active treatment period compared to temperate regions. In cold regions, current remedial strategies and on-site activities, regardless of the type of remediation technology, have often been designed to be effective only during the summer months (only 2 to 4 months per year).**Considering the large number of hydrocarbon-impacted sites and the environmental risks associated with toxic and carcinogenic hydrocarbon fractions, there is a strong demand for new research and development concerning more efficient, more cost-effective, and low-energy remediation technologies for hydrocarbon-impacted soil environments in cold climates. **My recent research shed light on how to overcome the current limitations of site remediation technologies applied to cold-climate sites. In the Discovery research, I will focus on how to accelerate the bioremediation during short summers and how to extend the bioremediation to non-summer months. My research program is divided into three themes: 1) New Approach for Assessing Bioremediation Feasibility and Selecting an Effective Strategy; 2) Accelerated Bioremediation during Short Summers; and 3) Extended Long-Term Bioremediation during Cold Months. The associated short-term objectives are to: **1. Quantitatively explain how bioaccessible microsites in soil particles are related to the enhancement of biodegradation activity and to the optimization of unfrozen water characteristics;*2. Develop a freeze-thaw induced Separation-Dissolution-Biodegradation (SDB) ex situ treatment to be applied during short summers in cold climates;*3. Enhance, measure, and predict microbial activity related to hydrocarbon biodegradation during non-summer months.**My research will be expanded in the long-term to produce `engineering products'. A larger-scale statistical decision-making system for bioremediation that can be linked to the Federal Contaminated Sites Inventory will be developed using the results from Theme 1. The SDB process developed in Theme 2 will be tested in scale-up systems in the field and will be considered a patentable technology. From Theme 3, the developed microbial activity model will be expanded to become an effective tool for climate change-adaptive remediation design and management for mine wastes buried in seasonally freezing and thawing or frozen ground. * *The expected outcomes of the research into expanding decision-making models, remediation strategies, and management principles to include periods beyond short summers will clearly benefit the Canadian public, provincial and federal contaminated site programs, and the energy, mining, and remediation industries.* *Overall, the proposed research related to the environmental sustainability of cold regions impacted by intensified natural resource development and industrial activities will contribute to meeting Canada's needs today and become one of the most important research fields for Canada's future. The research is thus on the frontline of Canada's innovation for sustainable development and environmental protection.