地下水石油烃污染厌氧生物刺激修复过程中的发酵产甲烷降解机制研究

The fermentative–methanogenic biodegradation process is a widespread degradation process in petroleum hydrocarbon contaminated sites, biostimulation aimed at this process to remediate groundwater has significant advantage in the cost and environmental impact. Deep understanding the reaction pathways of fermentative–methanogenic biodegradation processes is significant to carry out petroleum contaminants biostimulation. This proposal intends to carry out our research on the mechanism of fermentative–methanogenic biodegradation process in petroleum hydrocarbon contaminated sites, focus on the spatial and temporal evolution of metabolites, isotopic composition and community structure of microbial evolution in the fermentative–methanogenic biodegradation process under anaerobic biostimulation conditions. The target site is a typical petroleum contaminated groundwater sites in Jilin Oilfield, Jilin Province. Field monitoring, laboratory experiments, isotopic tracer and molecular biology methods will be applied in the survey. This research will reveal that the fermentative–methanogenic biodegradation pathways and mechanisms under natural conditions and biostimulation conditions, so as to provide a scientific basis for the development and rational regulation of petroleum contaminated environment remediation programs in fermentative–methanogenic conditions of contaminated site.

发酵产甲烷过程是地下水石油污染场地的一种重要的石油烃降解反应类型，针对该反应进行厌氧生物刺激修复在修复成本和环境影响方面具有显著优势。深刻理解生物刺激作用下石油烃的发酵产甲烷降解机制对于开展该环境中的厌氧生物刺激修复具有重要的科学意义和实际意义。申请项目拟选择吉林油田某典型地下水石油污染场地作为研究区，综合运用野外监测、室内模拟实验、环境同位素示踪和分子生物学方法，重点研究生物刺激条件下发酵产甲烷环境中石油烃污染组分的代谢产物含量、同位素组成和微生物群落结构的时空分布演化特征，揭示天然条件下和生物刺激修复过程中石油烃的发酵产甲烷降解途径和机制，从而为该环境中地下水石油污染修复方案的制定和合理调控提供科学依据。

石油烃的发酵产甲烷降解过程是石油污染场地污染源区地下水土中的关键反应过程，对于石油烃的自然衰减过程至关重要。选择最优的强化生物刺激方式促进该过程的进行，同时识别地下水中石油烃的具体发酵产甲烷降解机制是该方法实际应用中的重点和难点，也是目前相关研究的薄弱环节。本项目以吉林油田某污染场地作为研究区，通过野外监测、室内实验、环境同位素示踪、分子生物学相结合的方法，重点研究了生物刺激条件下发酵产甲烷环境中地下水石油烃污染组分及其代谢产物的含量、同位素组成和微生物群落结构的时空分布特征，揭示了天然条件下和生物刺激修复过程中地下水石油烃及其特征组分的发酵产甲烷降解机制。研究结果表明：在各种典型生物刺激物质当中，乙酸对萘的降解促进作用最为显著。投加甲酸、乙酸和磁铁矿作为刺激物质后主要的产甲烷反应机制分别为甲基营养型、乙酸发酵型和以“DIET”互营机制为主的氢营养型。研究成果为发酵产甲烷环境中地下水石油污染修复方案的制定和合理调控提供了科学依据。