||National Risk Management Research Lab., Ada, OK. Subsurfaces Protection and Remediation Div. ;Rice Univ., Houston, TX. ;ManTech Environmental Technology, Inc., Ada, OK.
A study was conducted to determine the microbial activity of a site contaminated with JP-4 jet fuel, before and during nitrate-enhanced bioremediation. Samples at three depths from six different locations were collected aseptically under anaerobic conditions before and during treatment. Cores were located in or close to the source of contamination, downgradient of the source, or outside the zone of contamination. Parameter for microbial characterization included (1) viable counts of aerobic heterotrophic, JP-4 degrading, and oligotrophic bacteria, (2) the MPN of aerobic and anaerobic protozoa, (3) the MPN of total denitrifiers, and (4) the MPN of denitrifiers in hydrocarbon-amended microcosms. The results indicate that the total number of denitrifiers increased by an order of magnitude during nitrate-enhanced bioremediation in most samples.