Pesticide Bioremediation – Landfarming Application for DDD, DDE and Toxaphene

Petrox® bioremediation was used to remediate pesticide-contaminated soil at an industrial location in California.

Soil Remediation

The soil contamination consisted of pesticides including 4,4-DDD, 4’4-DDE and toxaphene.  Soil samples were sent to CL Solutions for bench-scale treatability studies.   The following table shows the  maximum detected concentrations and the treatment results.

Contaminant
Untreated Concentrations (ug/Kg)
Post-treatment concentrations (ug/Kg)
4,4-DDD
390
250
4,4-DDE
380
220
Toxaphene
8,500
440

After the bench-scale verification, full-scale bioremediation was implemented.  The contaminated soil was placed in two stockpiles and treated with Petrox. The following table shows the pre- and post-treatment results.

Contaminant Concentrations (ug/Kg)
Contaminant
Pile 1
Pile 2
Before
After
Before
After
4,4-DDD
310
170
14
nd ( <5)
4,4-DDE
810
300
8.7
nd  (<5)
Toxaphene
12,000
7,300
380
nd (<5)

Conclusions

The Petrox treatment successfully reduced the concentrations of pesticide contaminants in the soil stockpiles.  For additional information or assessment of applicability to your site contact CL Solutions.

Bioremediation Product Safety

CL Solutions wants to assure you that our products are safe for human health.  All of our products are manufactured under strict health and safety protocols.  Starting with seed cultures, that are known to be safe, from known sources the cultures are grown in sterile sealed tanks.  The finished products are also stored in laboratory-clean areas.  Manufacturing and laboratory areas have separate ventilation systems to prevent product contamination.

Some other manufacturers of bioremediation products use open-top growing tanks that can be contaminated by atmospheric organisms.  These manufactures do not control the type of organisms that may be present in their products.

CL Solutions’ products are tested for viability and the absence of pathogens prior to shipping.  Not all bioremediation manufacturers follow the high QA/QC protocols of our manufacturer.

You can be confident with our bioremediation products that you will get only beneficial microbes and the products will be pathogen free.  These safety measures protect our workers, your workers, and people who live or work at the site.

 

 

 

Benzo(a)pyrene Bioremediation Using Custom Blend Microbes

Benzo(a)pyrene is a difficult remediation challenge. It is resistant to biological and chemical destruction and extraction from soil.  CL Solutions Custom Blend microbes, however, have successfully remediated benzo(a)pyrene and other PAHs in soil during ex situ land farming treatment.  By placing the contaminated  material in windrows, controlling the temperature and moisture, the addition of Custom Blend microbes has reduced the benzo(a)pyrene concentration by as much as 330 ug/kg/day.

The same approach works on high as well as low concentrations.  At a site in Oregon, the benzo(a)pyrene concentration was reduced from 140 ug/Kg to below detection limits in 7 days.  At a site in Ohio, the benzo(a)pyrene concentration was reduced from 28,000 ug/kg to 3.8 ug/Kg in 60 days.  At both sites, Custom Blend microbes effectively treated the full suite of PAHs along with the benzo(a)pyrene.

Clu-In Reports on Aerobic Cometabolism

The US EPA Technology and Field Services Division produced a report on aerobic cometabolism of chlorinated solvents under their Contaminated Sites Clean-Up Information program on February 7, 2019.  This report includes an overview of aerobic cometabolism and guidance on application and monitoring.  Click here to link to the report.

While the report cites the research of Thomas Wood, et. al., it does not include the research demonstrating aerobic cometabolism of PCE.  The following links go to the research on aerobic cometabolism of PCE.

https://www.che.psu.edu/faculty/wood/group/publications/pdf/PCEMixturedeg.pdf

https://www.academia.edu/3299440/Aerobic_degradation_of_tetrachloroethylene_by_toluene-o-xylene_monooxygenase_of_Pseudomonas_stutzeri_OX1

One of the benefits of aerobic cometabolism is the applicability of bioremediation to shallow soil and ground water that may cause vapor intrusion risk at dry cleaners.  Removing the source of the vapors under natural conditions,without business interruption, is the most economical and sustainable solution.

CL Solutions’ CL-Out consortium has been used for bioremediation of PCE and other chlorinated solvents at dry cleaners and industrial sites since 1999.  Contact CL Solutions for information and a site evaluation.

New Chlorinated Solvent Results

CL-Out bioremediation continued to show outstanding results in bioremediation of PCE, TCE and other chlorinated solvents at three recent applications. Results show more than 90% PCE removal with a single application of CL-Out for in situ ground water treatment. The PCE remediation did not cause an increase in vinyl chloride showing that the breakdown pathway was by dioxygenase cometabolism and not by reductive dechlorination.

A site in Massachusetts showed the following ground water results:
PCE 1,100 ug/L reduced to 30 ug/L, 97% removed
TCE 39 ug/L reduced to 5.6 ug/L, 85% removed
No other daughter products were detected.

Ground water remediation in Florida showed these results:
PCE 182 ug/L reduced to 16.1 ug/L, 91% removed
TCE 9.82 ug/L reduced to 2.77 ug/L, 71% removed
cis 1,2 DCE 3.26 ug/L reduced to 0.282 ug/L, 91% removed
vinyl chloride was not detected before or after bioremediation.

Ground Water contamination at a site in New Jersey followed the same trend:
PCE 690 ug/L reduced to less than 5 ug/L, 99% removed
TCE 7,980 ug/L reduced to less than 810 ug/L, 89% removed
No breakdown products were detected.

These sites join the hundreds of sites remediated by CL-Out aerobic cometabolism.