乙醇对含水层中燃油芳香烃内在生物修复的潜在风险

内在生物修复,是在没有工程措施促进的情况下利用土著微生物降解含水层内灾害性物质的一种修复技术,在燃油烃污染管理方面具有显著的成本效益。该技术需要确定自然衰减过程,并能够继续提供有效的风险保护。针对燃油污染含水层,北美与欧洲认为内在生物修复是值得优先考虑的应用技术。然而,随着乙醇燃油的推广使用,我国在应用这样的经验时需要考虑乙醇的潜在影响。现有的文献研究表明乙醇存在能够阻止燃油主要污染物芳香烃(BTEX)的生物降解,降低水环境的pH值,并可能增强BTEX在水中的溶解性,或存在对生物的毒性,或因为乙醇降解降低介质的渗透性能。因此,需要更好地认识乙醇的潜在风险,为发展乙醇燃油污染含水层修复策略提供科学依据。

Potential Risk of Presence of Ethanol on Intrinsic Bioremediation of Aromatic Hydrocarbons in Groundwater Contaminated by Fuel

Intrinsic bioremediation which uses indigenous microorganisms to degrade hazardous substances within aquifers without engineered enhancement,shows great promise as a cost -effective approach to management of fuel hydrocarbon plume. The technique which requires monitoring to ensure the existence of natural attenuation process and continues to provide adequate risk protection has been considered as a preferential technique to manage fuel-contaminated aquifers in North American and Europe. However,the experience should be extrapolated with caution to contaminated sites in China,where gasoline will increasingly contain about 10% of ethanol. Literatures showed that ethanol can inhibit the intrinsic bioremediation of aromatic hydrocarbons,and decrease pH value in groundwater environment. Additionally,it might stimulate BTEX solubility and affect the permeability of aquifer. A better understanding of the potential effects of ethanol on intrinsic bioremediation of fuel hydrocarbon plume should be needed to develop a rational basis for the assessment of intrinsic bioremediation in groundwater contaminated by ethanol blended gasoline.