Biodegradation of cycloalkanes under different redox conditions

露天开采和热水沥青提取作业有几个问题；其中一个重要的问题是管理大量流动的细粒尾矿。非水溶剂萃取(NAE)工艺具有减少油砂活动对环境的影响的潜力，因为它可以产生高回收率的沥青，消除产生液体细尾矿，并减少对新鲜水消耗的依赖。此外，使用混合了原始土壤的NAE固体可以更快地开垦矿场。在NAE提取沥青后，大部分溶剂从工艺中回收并重复使用，但一小部分未回收的溶剂仍与NAE固体结合并共沉积。找到一种安全、快速地从NaE中去除未回收的溶剂的方法，将有利于矿场的复垦。生物修复是处理含碳氢化合物尾矿的一种经济有效的方法。利用土壤微生物群落降解NAE固体中的残留溶剂的能力可以减少对环境的影响，如果NAE固体沉积在坑中或在旱地或湿地情况下进行管理。在拟议的研究中，我们将通过在实验室建立小型微型实验来模拟土坑(好氧/厌氧)、旱地(好氧)和湿地(厌氧)场地条件，并研究在不同氧化还原条件(好氧、硝酸盐还原、硫酸盐还原和产甲烷)下浸渍了环戊烷和环己烷的NAE固体的生物修复。

Surface mining and hot water bitumen extraction operations have several issues; the significant one is the management of enormous volumes of fluid fine tailings. Non-aqueous solvent extraction (NAE) process has a potential to reduce environmental impact of oil sands activity by yielding high recovery of bitumen, eliminating production of fluid fine tailings and reducing dependence on fresh water consumption. In addition, mine sites might be reclaimed more rapidly using NAE solids mixed with pristine soils. After NAE extraction of bitumen, the majority of the solvent is recovered from the process and re-used, but a small portion of unrecovered solvent remains incorporated and co-deposited with NAE solids. Finding a way to safely and rapidly remove the unrecovered solvent from NAE will benefit mine site reclamation. Bioremediation is a cost-effective method to treat tailings containing hydrocarbons. The ability to use soil microbial communities for the degradation of residual solvent from NAE solids could reduce the environmental impact if NAE solids are deposited in pits or managed under upland or wetland scenario. In the proposed research, we will be simulating soil-pit (aerobic/anaerobic), upland (aerobic) and wetland (anaerobic) site conditions by setting up microcosm experiments at small-scale in the laboratory and investigate bioremediation of NAE solids impregnated with cyclopentane and cyclohexane under different redox conditions (aerobic, nitrate-reducing, sulfate-reducing and methanogenic).