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

在加拿大，联邦污染场地清单列出了21 000多个被污染或疑似被污染的场地。在约80%的受污染场地中，土壤环境受到污染，包括表层和次表层土壤、沉积物和地下水。在这些地点最常发现的污染物是石油碳氢化合物，这是一种非水相液体，包括有毒和致癌的有机化合物。在加拿大的许多受污染场地，碳氢化合物污染存在于寒冷气候的土壤环境中。寒冷地区的地面一年中有6至9个月保持半冻结和冻结状态，与温带地区相比，这大大缩短了积极治疗期。在寒冷地区，目前的补救战略和现场活动，无论补救技术的类型如何，往往只在夏季有效（每年只有2至4个月）。考虑到受碳氢化合物影响的地点数量众多，以及与有毒和致癌碳氢化合物馏分有关的环境风险，对于在寒冷气候中受碳氢化合物影响的土壤环境的更有效、更具成本效益和低能耗的补救技术，存在着对新的研究和开发的强烈需求。我最近的研究揭示了如何克服目前适用于寒冷气候地区的场地修复技术的局限性。在探索研究中，我将专注于如何在短暂的夏季加速生物修复，以及如何将生物修复扩展到非夏季月份。我的研究计划分为三个主题：1）评估生物修复可行性和选择有效策略的新方法; 2）在短期夏季加速生物修复;和3）在寒冷的月份延长长期生物修复。相关的短期目标是：1。定量解释了土壤颗粒中生物可及微位点与生物降解活性增强和未冻水特性优化的关系;2.开发一种冻融诱导的分离-溶解-生物降解（SDB）非原位处理方法，应用于寒冷气候下的短夏;3.增强，测量和预测在非夏季月份与碳氢化合物生物降解相关的微生物活性。我的研究将在长期内扩大到生产“工程产品”。将利用专题1的结果开发一个可与联邦污染场地清单相联系的生物补救的大规模统计决策系统。主题2中开发的SDB工艺将在现场放大系统中进行测试，并将被视为可申请专利的技术。从主题3开始，开发的微生物活性模型将被扩展成为一个有效的工具，用于季节性冻融或冻土中埋置的矿山废物的气候变化适应性修复设计和管理。扩大决策模式，补救策略和管理原则，包括短期夏季以外的研究的预期成果将明显有利于加拿大公众，省级和联邦污染场地计划，能源，采矿和补救行业。总的来说，拟议的研究与受强化自然资源开发和工业活动影响的寒冷地区的环境可持续性有关，将有助于满足加拿大今天的需求，并成为加拿大未来最重要的研究领域之一。因此，该研究处于加拿大可持续发展和环境保护创新的前沿。

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.