Aerobic PCE Bioremediation

CL-Out Aerobic PCE Bioremediation Pilot Study Results

A CL-Out bioremediation pilot study confirmed that aerobic PCE cometabolism removed dry cleaning solvent contamination from ground water.  The pilot study was located at a former dry cleaners.  At the site, the PCE in ground water was 27 parts per billion (ppb).  Bioaugmentation introduced CL-Out microbes and dextrose as the metabolic substrate by injected into the ground water up gradient 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 from 1.07 to 0.71 mg/l.  Meanwhile,  the ORP decreased from 99 to 45 mv.  These aerobic aquifer conditions support the conclusion that the PCE removal was through aerobic bioremediation.

CL-Out cometabolism uses 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.

CL-Out is a consortium of naturally-occurring microbes.  The microbes have the benefits of metabolic diversity and environmental stability.  They are non-pathogenic and safe for human health and the environment. Click here to find out more about CL-Out bioremediation.

 

 

Bioremediation of Phthalates

Bioremediation of phthalatescan reduce risks to human health and the environment.  Phthalates are a  a family of common industrial chemicals used in plastics and other consume products.  Phthalates can damage the liver, kidneys, lungs and reproductive system.  Petrox microbes can remove these contaminants from water or soil to reduce potential exposure to these risks.

Petrox bioremediation of phthalates has been demonstrated in field and laboratory studies to remove phthalates from soil and ground water.  Field application of Petrox bioremediation reduced bis(2-ethylhexyl)phthalate (BEP) concentrations from 650 ppm to 397  ppm in soil and 300 to 39 ppb in ground water at a site in Rochester, New York.  At the same site di-n-octylphthalate (DOP) in soil was reduced from 7.5 to 1.9 ppm. Click here to view the case study.

PCE Aerobic Bioremediation by Key-hole Source Removal

CL-Out aerobic PCE bioremediation in a keyhole treatmentreduced the mass of contamination near the source and down gradient concentrations in the plume.  At a former manufacturing facility in Ohio the concentration of PCE near the source was over 100,000 ug/L.  Down gradient of the source the PCE concentrations were less than 10% of the source concentration.  Aggressive treatment in the source area reduced the source concentration and in the down gradient plume.

Source area concentrations decreased as follows after one treatment with CL-Out bioremediation:

  • PCE decreased from 120,000 to 12 ug/L.
  • TCE decreased from 2,000 to 12 ug/L
  • Cis 1,2-DCE decreased from 9,500 to 8,100 ug/L.
  • Vinyl chloride, however, increased from 1,200 to 22,000 ug/L.

The vinyl chloride increased as the aggressive cometabolic treatment stimulated  incomplete reductive dechlorination by other naturally occuring organisms.

Down gradient from the source, the concentrations decreased with slight to no increase in daughter products.  The  down gradient plume had the following results:

  • PCE decreased from 5,000 to 1,600 ug/L.
  • TCE decreased from 43 ug/L to BDL.
  • Cis 1,2-DCE decreased from 140 to 23 ug/L.
  • Vinyl chloride  was not detected before or after treatment.

Keyhole treatment was a cost effective approach to reducing the mass of contamination in a ground water plume by focusing aggressive treatment on the source area.  Concentrations in the rest of the plume decreased as the microbes and treated water dispersed through the plume.

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.

Click here to learn more about CL-Out bioremediation.

Aerobic Cometabolism of TCE and 1,4-Dioxane – Field Demonstration

In a pilot study to compare aerobic cometabolism with anaerobic reductive dechlorination  to remediation TCE and 1,4-dioxane at a former industrial facility in New Jersey, aerobic cometabolism reduced the concentrations of both compounds while anaerobic reductive dechlorination was unsuccessful.  For aerobic cometabolism, CL-Out microbes were injected into the aquifer to a depth of 60 to 90 feet below ground.  The pilot treatment area was 500 square feet.  Monitoring wells were placed upgradient, sidegradient and downgradient of the injection point.  Ground water samples were taken on a monthly basis for 9 months.

The results showed that complete TCE mineralization, without the production of daughter products, was measured within the first month.  CL-Out bioremediation removed 80% of the TCE at 40 feet downgradient in less than three months.  CL-Out bioremediation reduced the 1,4-dioxane concentration to below detection limits at 20 and 40 feet downgradient in the first month.

Click here to view a summary case study.

 

 

1,1,1-TCA Bioremediation at an Industrial Site in Dayton, Ohio

CL-Out bioremediation reduced the concentration of 1,1,1-TCA in ground water at a steel manufacturing facility in Dayton, Ohio. Following implementation of ozone treatment and high vacuum extraction for more than 2 years, the contaminant concentrations remained high.  Bioaugmentation followed up on these treatments and reduced the 1,1,1-TCA concentration very quickly.  Within 30 days of bioaugmentation, the source area contaminant concentration decreased by 80%.  After a second application, the concentration decreased from the pre-treatment concentration of 1,100 ug/L to 1.4 ug/L.  The bioaugmentation effect was observed as far as 250 feet downgradient where the concentrations decreased by more than 50%.  Click here for the full case study.