Impact of Aged Contamination on Bioventing Performance

被石油碳氢化合物污染的场所是一个全球性的挑战。场地修复是一项大生意，业主和政府都在寻找成本效益高、对环境负责的方法来清理这些场地。生物排气是一种修复方法，它被归类为生物刺激方法，通过向土壤中添加氮来刺激土壤中的石油降解物，从而降低石油烃污染水平。然而，需要进行研究来确定这些泄漏对修复工作的影响。具体来说，老化如何影响降解速率、将实验室结果推广到现场时的放大因子以及降解过程中代谢物的发展？使用200克呼吸计和4公斤反应器的降解研究将用于研究使用合成汽油的不同类型的老化过程和持续时间。两种反应器尺寸的各种生物通气条件将允许测定在不向土壤中添加改良剂时的降解速率，评估添加改良剂（如营养物和生物炭）的降解速率，提取效率作为老化的函数，以及鉴定可能的代谢物形成。比较一级降解率，以及提取效率和代谢物形成数据将确定关键因素。由此产生的老化数据将确定对生物利用度的影响，改进在几十年前污染的地点实施生物通风。从实验室实验中获得的降解率将允许开发三维生物通气模型。该模型将为顾问提供一种工具，通过这种工具，他们可以预测特定地点生物通风的有效性，并估计达到关闭所需的时间，这是网站所有者和政府官员一直在问的问题。拥有这样的工具可以帮助加拿大和世界各地的石油污染场地进行经济有效的修复，提供许多就业机会。

Sites contaminated with petroleum hydrocarbons are a challenge worldwide. Site remediation is big business, with owners and governments looking for cost effective, yet environmentally responsible methods to clean up these sites. Bioventing is such a remediation method that it is classified as a biostimulation approach, where nitrogen is added to the soil to stimulate the petroleum degraders in the soil to reduce the petroleum hydrocarbon contamination level. However, studies are needed to determine how aged spills impact remediation efforts. Specifically, how does aging affect the degradation rate, the scale-up factor when extending the lab results to the field and the development of metabolites through the degradation process? Degradation studies using 200 g respirometers and 4 kg reactors will be used to investigate different types of aging procedures and durations using synthetic gasoline. Various bioventing conditions for both reactor sizes will allow determination of the degradation rate when no amendments are added to the soil, evaluation of degradation rate with amendments like nutrients and biochar, extraction efficiency as a function of aging and identification of possible metabolite formation. Comparing the first order degradation rates, along with extraction efficiencies and metabolite formation data will identify the critical factors. The resulting aging data will identify the impact on bioavailability, improving the implementation of bioventing at sites with decades old contamination. The degradation rates obtained from the laboratory experiments will allow development of a 3-D bioventing model. This model will give consultants a tool by which they can predict the effectiveness of bioventing for a given site and estimate the time needed to attain closure, a question site owners and government officials continue to ask. Having such a tool can assist with the cost effective remediation of petroleum contaminated sites in Canada and the world, providing many job opportunities.