Pilot Study Confirms Aerobic Cometabolism of PCE at Kentucky Site
A CL-Out bioremediation pilot study confirmed the PCE could be removed from ground water by aerobic cometabolism. The pilot study was at the former location of a dry cleaners where PCE wasfound in ground water at 27 parts per billion (ppb). CL-Out micorbes and dextrose as the metabolic substrate were injected into the ground water upgradient from the sentinal monitoring well. After 30 days the PCE concentration decreased to 20 ppb. After 6 months the PCE concentration decreased to 16 ppb.
As the PCE was decreasing the site conditions stayed aerobic. The dissolved oxygen level in ground water decreased 1.07 mg/L to 0.71 mg/l and the ORP decreased from 99 to 45 mv.
CL-Out cometabolism used a dioxygenase enzyme that is produced constituatively as the metabolic substrate is consumed. The dioxygenase enzyme destabilizes the carbon bond in the PCE to convert the molecule to an organic acid that leads to complete mineralization.