Aix-Marseille Université-CNRS, Laboratoire Chimie Environnement FRE, 3416 Marseille, France; French Environment and Energy Management Agency, 20 avenue de Grésillé, BP 90406 Angers Cedex 01, France.
ICF Environnement, 14/30 rue Alexandre Bâtiment C F, 92635 Gennevilliers, France.
Sci Total Environ. 2015 Apr 15;512-513:62-73. doi: 10.1016/j.scitotenv.2015.01.033. Epub 2015 Jan 21.
A pipeline transporting crude-oil broke in a nature reserve in 2009 and spilled 5100 m(3) of oil that partly reached the aquifer and formed progressively a floating oil lens. Groundwater monitoring started immediately after the spill and crude-oil recovery by dual pump-and-skim technology was operated after oil lens formation. This study aimed at documenting the implementation of redox-specific natural attenuation processes in the saturated zone and at assessing whether dissolved compounds were degraded. Seven targeted water sampling campaigns were done during four years in addition to a routine monitoring of hydrocarbon concentrations. Liquid oil reached the aquifer within 2.5 months, and anaerobic processes, from denitrification to reduction of sulfate, were observable after 8 months. Methanogenesis appeared on site after 28 months. Stable carbon isotope analyses after 16 months showed maximum shifts in δ(13)C of +4.9±0.22‰ for toluene, +2.4±0.19‰ for benzene and +0.9±0.51‰ for ethylbenzene, suggesting anaerobic degradation of these compounds in the source zone. Estimations of fluxes of inorganic carbon produced by biodegradation revealed that, in average, 60% of inorganic carbon production was attributable to sulfate reduction. This percentage tended to decrease with time while the production of carbon attributable to methanogenesis was increasing. Within the investigation time frame, mass balance estimations showed that biodegradation is a more efficient process for control of dissolved concentrations compared to pumping and filtration on an activated charcoal filter.
一条输送原油的管道于 2009 年在自然保护区破裂，泄漏了 5100 立方米的石油，其中部分石油到达了含水层，并逐渐形成了一个浮动的油透镜。泄漏发生后立即开始进行地下水监测，并在油透镜形成后采用双泵抽吸技术进行了原油回收。本研究旨在记录饱和带中氧化还原特异性自然衰减过程的实施情况，并评估是否降解了溶解的化合物。在四年期间进行了七次有针对性的水样采集活动，此外还定期监测了碳氢化合物浓度。液态油在 2.5 个月内到达含水层，并且在 8 个月后可以观察到从反硝化到硫酸盐还原的厌氧过程。28 个月后甲烷生成在现场出现。16 个月后的稳定碳同位素分析表明，甲苯的 δ(13)C 最大偏移为+4.9±0.22‰，苯为+2.4±0.19‰，乙基苯为+0.9±0.51‰，这表明这些化合物在源区发生了厌氧降解。对生物降解产生的无机碳通量的估算表明，平均有 60%的无机碳生产归因于硫酸盐还原。随着时间的推移，这一比例呈下降趋势，而归因于甲烷生成的碳的产量却在增加。在调查时间范围内，质量平衡估算表明，与使用活性炭过滤器进行泵送和过滤相比，生物降解是控制溶解浓度的更有效过程。
