Biodegradation of petroleum constituents by aquifer microbial communities
The potential for in situ bioremediation of two petroleum contaminated aquifers was investigated. Several samples from various areas and depths at the sites were collected from the aquifers. The general characteristics of community size in each sample was assessed using acridine orange direct counts (AODC), plate counts, and {sup 14}C most probable number (MPN) of amino acid degrader determinations. Metabolic activity in each sample was assessed by amino acid mineralization time course analysis and mass balance analysis of amino acid metabolism. Pollutant biodegradation potential was determined by assessing the fate of the target pollutants decane and toluene using batch microcosms. All samples were of a sandy texture, except for one which was predominantly clay. All samples tested, both contaminated and uncontaminated, contained sizable microbial communities as determined by AODC. With the exception of the clay sample, which exhibited no metabolic activity in either of the two methods used, all samples contained metabolically active communities. Plate count and MPN data indicate that approximately 1 to 10 percent of the total populations enumerated with AODC were metabolically active. Amino acid mineralization and metabolism was rapid in all samples tested with the exception of the clay sample. Mineralization time course analyses indicated that the microbial communities present in both contaminated and uncontaminated samples were capable of degrading both decane and toluene without any apparent adaptation period. Decane was metabolized to a greater extent than toluene. Mass balance analyses and solid/liquid phase separation techniques indicated that a portion of the test hydrocarbons were converted to water soluble metabolic intermediates within minimal incorporation into cellular material. The proportions of metabolized pollutant that represented each compartment changed over time, with mineralization and metabolite fractions increasing.
- Research Organization:
- North Carolina Univ., Chapel Hill, NC (United States)
- OSTI ID:
- 68638
- Resource Relation:
- Other Information: TH: Thesis (Ph.D.); PBD: 1994
- Country of Publication:
- United States
- Language:
- English
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