In Situ Biodegradation Potential in Petroleum Hydrocarbon-Contaminated Soils Exposed to Seasonal Freeze-Thaw Conditions.

石油碳氢化合物是非水相液体(NAPL)，包括致癌和有毒有机物质 化合物，在受石油开采和运输影响的土壤环境中是令人担忧的原因， 意外漏油，以及油砂废物的处置。根据联邦污染场地的说法 在加拿大，最常见的污染物是石油碳氢化合物，以及许多 加拿大受污染的地点受到寒冷气候季节性的影响。刺激适应寒冷的本土人 细菌降解碳氢化合物一直被认为是一种可行、破坏性较小和低成本的补救选择 适用于寒冷气候下夏季温度下的碳氢化合物污染土壤。然而，寒冷地区的土壤 保持部分冻结，每年冻结6至9个月，这大大缩短了积极补救的时间 目前在寒冷气候下的补救措施被认为只在短期内有效。 夏季(2-4个月)，主要原因是非夏季气温较低和场地通达性有限 月份。然而，Won Jae Chang博士最近的研究表明，微生物具有巨大的潜力 碳氢化合物污染土壤在季节性冻融条件下的增强 寒冷气候中的夏后。这一新发现为拟议的试点规模传记片提供了理论基础 现场研究石油烃污染土壤中的原位生物降解潜力 季节性冻融条件。缺乏关于碳氢化合物生物降解程度的现场数据。 以及自然季节性冻融温度下受污染土壤中的微生物反应。变化 在季节性冻融期，土壤温度和未冻土壤水分的变化速度远远慢于 在以前的许多实验室冻融研究中使用，并提供了本地所需的真实条件 碳氢化合物降解菌在寒冷的土壤中生存和/或适应环境压力。建议数 研究将通过监测自然温度循环下的微生物活动来产生现场数据，并将 因此，为环境挑战条件下的生物修复提供了新的见解。

Petroleum hydrocarbons are non-aqueous phase liquids (NAPLs) that include carcinogenic and toxic organic compounds, and are a cause for concern in soil environments impacted by oil extraction and transportation, accidental oil spills, and the disposal of oil sands wastes. According to the Federal Contaminated Sites Inventory, the most frequently identified contaminants in Canada are petroleum hydrocarbons, and many contaminated sites in Canada are influenced by cold-climate seasonality. Stimulating indigenous cold-adapted bacteria to degrade hydrocarbons has been considered a feasible, less destructive, and low-cost remedial option for hydrocarbon-contaminated soils at summer temperatures in cold climates. However, soils in cold regions remain partially frozen and frozen for 6 to 9 months each year, which greatly shortens the active remediation period, and current remediation practices in cold climates have only been considered effective during short summers (2-4 months), mainly due to colder temperatures and limited site accessibility during non-summer months. Dr. Won Jae Chang's recent study, however, indicated a significant potential for microbial enhancement in hydrocarbon-contaminated soils under seasonal freeze-thaw conditions during pre- and post-summers in cold climates. This new finding provides the rationale for this proposed pilot-scale biopile field study entitled In Situ Biodegradation Potential in Petroleum Hydrocarbon-Contaminated Soils Exposed to Seasonal Freeze-Thaw Conditions. There is a lack of field data about the extent of hydrocarbon biodegradation and microbial response in contaminated soils subjected to natural seasonal freeze-thaw temperatures. Changes in soil temperatures and unfrozen soil water during seasonal freeze-thaw periods are much slower than the rates used in many previous laboratory freeze-thaw studies, and provide the real conditions needed for native hydrocarbon-degrading bacteria to survive and/or adapt to environmental stresses in cold soils. The proposed study will generate field data by monitoring microbial activity under natural temperature cycles and will therefore provide new insight for bioremediation in environmentally challenging conditions.