Aerobic Cometabolism of Chlorinated Solvents

CL-Out® aerobic cometabolism successfully remediated solvents in ground water at an operating industrial site in central New Jersey.  The manufacturing and plating facility had historical petroleum and solvent releases.

Chlorinated solvents found in the ground water in two plumes covered a combined area of about one half acre.  A mix of chlorinated solvents including 1,1,1-TCA, 1,1-DCE and PCE in low concentrations icontaminated the ground water.    The remediation goal was to reduce the mass of contamination in the ground water plume to prevent mitigate off-site risks.

After the CL-Out aerobic cometabolism, ground water concentrations in all monitoring wells decreased by more than 80%, which was sufficient to meet the remediation standards.  Click here to download a complete case study.

What enzymes Are Involved in Aerobic Bioremediation of PCE and TCE?

CL-Out aerobic bioremediation PCE and TCE is a sustainable process for soil and ground water remediation.  As these compounds are not directly metabolized under aerobic conditions, the competitive advantage goes to the CL-Out organisms that cometabolize them.  While utilizing a sugar substrate, the CL-Out organisms produce  mono- and dioxygenase  enzymes that bridge the carbon bond to destabilize the compound.   The solvent is converted to an organic acid that the organism can metabolize.  View the degradation pathway.  The benefit is that CL-Out bioremediation can be applied to soils both in situ and ex situ.  Click here for to download a case study.  For further explanation call CL Solutions at 513-284-5940.

CL-Out Bioaugmentation Following ISCO to Remediate TCE

Bioremediation used to complete closure

CL-Out bioremediation was used to remediate ground water at an active manufacturing plant in eastern Massachusetts after ISCO treatment of TCE in groundwater reached a limit.  CL-Out was selected because the aquifer was naturally aerobic.  CL-Out cometabolizes TCE and other chlorinated solvents under aerobic conditions by producing an oxygenase enzyme that breaks the carbon to carbon bond.  Under aerobic conditions daughter products such as DCE and vinyl chloride are not formed. Thirty days after one application of CL-Out the TCE concentration was reduced by 97% and the site remediation goals were achieved. Click here to download the case study.

PCE Bioremediation in Aerobic Groundwater

PCE bioremediation in aerobic groundwater by CL-Out microbes reduced environmental risk at a printing company in Kentucky.  Testing found high concentrations of PCE in perched ground-water.  The ground water aquifer was in sn alluvial sand deposit with high permeability.  The high permeability facilitated injection for in situ treatment.  Also, the high permeability of the aquifer matrix also supported aerobic ground water conditions.  With one application of CL-Out the concentration of PCE decreased from 3,600 ug/L to 250 ug/L in less than 45 days.  With further applications the concentration was reduced to below detection limits in 10 months.

Aerobic PCE Bioremediation By Cometabolism

CL-Out is a consortium selected for aerobic PCE bioremediation.  CL-Out cometabolizes PCE by growing on a simple sugar and producing a metabolic enzyme to degrade PCE.  The microbes produce a dioxygenase enzyme that breaks the carbon bond in PCE.  This reaction eliminates the biproducts of reductive dechlorination.  Also, the synergistic effect of the CL-Out consortium cometabolizes the full suite of chloroethenes and chloroethanes. Read more…

Click here for more information about CL-Out bioremediation.

TCE Bioremediation Rates

The following chart is a compilation of TCE bioremediation rates by CL-Out microbes.  This data is from eleven different sites where ground water was contaminated by trichloroethylene (TCE) and remediatedby CL-Out microbes.  The sites represent all kinds of geological conditions with the full range of TCE concentrations in ground water.

Overall, the results show an average removal rate of 97% .  However, the final TCE concentration reached below detection limits on two sites, and an additional three had greater than 99% removal.