Impact of Aged Contamination on Bioventing Performance

受石油碳氢化合物污染的场地是全世界面临的一个挑战。 场地修复是一项大业务，业主和政府正在寻找具有成本效益但对环境负责的方法来清理这些场地。 生物通风是这样一种补救方法，它被归类为生物刺激方法，其中向土壤中添加氮以刺激土壤中的石油降解剂，从而降低石油烃污染水平。 然而，需要进行研究，以确定陈旧的溢漏如何影响补救工作。 具体而言，老化如何影响降解速率、将实验室结果扩展到现场时的放大系数以及降解过程中代谢产物的形成？** 使用200 g呼吸计和4 kg反应器进行的降解研究将用于研究使用合成汽油的不同类型的老化程序和持续时间。 两种反应器规模的各种生物通风条件将允许确定在土壤中不添加改良剂时的降解率，评估添加营养物和生物炭等改良剂的降解率，提取效率作为老化的函数，并确定可能的代谢物形成。 比较一级降解速率、沿着浸提效率和代谢产物形成数据，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，改善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风模型。这一模式将为顾问提供一种工具，使他们能够预测生物通风对某一场址的有效性，并估计实现关闭所需的时间，这是场址所有者和政府官员继续提出的一个问题。拥有这样的工具可以帮助加拿大和世界上石油污染场地的成本效益补救，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.*****