Using Phospholipid Fatty Acids to Characterize In-Situ Biodegradation of Organic Compounds in Ground Water

摘要

Natural attenuation of organic compounds in ground water can be a corrective action alternative at contaminated sites either as a sole remedy or remedy component, usually depending upon the nature of the contaminant source (USEPA, 1997). Of all the natural attenuation processes present in ground water, in-situ bioldegradation may be preferred because it destroys, rather than retards or dilutes masses of organic compounds of interest. Thus, the focus of many recent natural attenuaation or "intrinsic remediation" evaluation has been to characterize the predominant biological processes present that degrade organic compounds using geochemical and traditional microbiological methods. Geochemical analysis of ground water can be used to qualitatively and quantitatively evaluate oxidation-reduction (redox) zonation, nutrient availability, and limiting factors for biomass growth. Traditional microbiological methods that involve isolation and culturing (e.g, plate counting methods) can provide information on the presence or absence of specific types or classes of microorganisms (Alexander, 1977). However, geochemical and traditional microbiological methods provide little indication of the in-situ status of microbial populations in subsurface environments (White, et al, 1996a).