Principles and Practices of Enhanced Anaerobic Bioremediation of Chlorinated Solvents

摘要

The Department of Defense (DoD) has identified hundreds of sites where groundwater is contaminated with chlorinated solvents; these represent one of the DoD's largest remediation liabilities. In addition to their use in many industrial processes, chlorinated solvents have historically been used for cleaning and degreasing such diverse products as aircraft engines, automobile parts, electronic components, and clothing in the military and commercial sectors. Chlorinated solvents were often released to the subsurface environment in waste water or in the form of dense non-aqueous phase liquids (DNAPLs). As a result of their physical and chemical properties, DNAPLs are difficult to remediate once they have migrated into groundwater aquifers. Enhanced in situ anaerobic bioremediation can be an effective method of degrading various chlorinated solvents dissolved in groundwater, including chloroethenes, chloroethanes, and chloromethanes. Collectively, these compounds (some of which are degradation products of chlorinated solvents) are referred to as chlorinated aliphatic hydrocarbons (CAHs). Advantages of enhanced anaerobic bioremediation include complete mineralization of the contaminants in situ with little impact on infrastructure and relatively low cost compared to more active engineered remedial systems.