Choosing The Right Product For Ex Situ Petroleum Bioremediation

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Selecting the right product for ex situ petroleum bioremediation comes down to usability factors.  Both Petrox and Custom Blend products quickly degrade petreleum in soil.  The average petrolem removal rate for Petrox bioremediation is 68 mg/kg/day.  The average removal rate for Custom Blend is 1,315 mg/kg/day.  The actual field results can vary depending of the effective distribution if microbes in the soil, field temperature, moisture, soil type and the type of hydrocarbon.

Petrox is a blend of microbes that requires freeze-drying to preserve high microbial yields.  Petrox must be kept frozen prior to use and must be hydrated before application to the soil.

Custom Blend microbes are spore-forming organisms and can be stored at room temperature until ready to be used.  The Custom Blend microbes should be mixed with water to make the application easier,  Custom blend is more suitable for routine use because it can be stored until it is needed.

 

Sustainable Green Remediation Saves Time And Money

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Sustainable, green remediation is recommended to reduce the environmental impact of the removal of existing soil or groundwater contamination.  It has the added benefit of reducing costs and accelerating remediation to save time.

Following the ASTM standards greener remediation best management practices, Irwin Engineering saved time and money for their client in the removal of nitrate and perchlorate contamination using CL-Out bioremediation.  Most of the savings came from switching from ground water extraction and treatment using ion-exchange to in situ bioremediation.

Using best management practices saved the following amount of money:

  • Reused existing piping and structures – saved $10,000.
  • Switched from ground water extraction for thermal treatment to in situ bioremediation – saved $2-3 million.
  • Close delineation and remediation planning to reduce treatment volumes – saved $1-2 million.
  • On-site biological treatment of well development water – saved $15,000.
  • Used ion specific probes to optimize lab performance – saved $20,000.
  • Used vegetation testing to delineate plume in the wetland – saved $50,000.
  • Used horizontal wells for bioremediation injection where appropriate – saved $30,000.

Overall project savings $3 to $5 million.

Overall time savings 3 to 5 years.

The property was sold to a new owner and transferred without impairment.

Click here for more project details and insights.

Click here for more information about Irwin Engineering and their award for greener remediation.

 

TPH Spill Into Lagoon Bioremediation

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Delta Remediation of Alberta, Canada remediated an accidental release of petroleum into a wastewater treatment lagoon using Biologix, which is a specialty blend of micorbes provided by CL Solutions.  The TPH concentrations were reduced from 4,300 mg/L to 32 mg/L in 4 days.

   

Photographs of the lagoon before and after  bioremediation of TPH spill using Biologix.

 

Fast BTEX and Methylnaphthalene Bioremediation

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Petrox and Methylnaphthalene Bioremediation Site Summary

Petrox microbes accelerated BTEX and methylnaphthalene bioremediation at a former fueling station in Florida.  After a leaking tank underground storage tank (UST) was removed,  the consultants injected Petrox micorbes into the groundwater. A temporary well showed high concentrations of BTEX, methylnaphthalene isomers, and total recoverable petroleum hydrocarbons (TRPH) in the former tank location.  A permanent monitoring point replaced the temporary well. Since the contaminants were not detected outside of the UST cavity, the treatment focused on the cavity and its proximity. The consultant injected Petrox  into the ground water through 12 direct-push injection points in and around the UST cavity. They used approximately 10 gallons of Petrox solution at each of the injection points in August 2001. After one injection of Petrox, petroleum hydrocarbons concentrations decreased below detection levels in the UST cavity.  Please refer to the table below for the ground water monitoring results.

Persistence in Soil and Low Ground Water Concentrations

Methylnaphthalene and naphthalene persist in soil after other volatile components of fuels are gone.  The persistence comes from to their relatively high affinity for adsorption to soil and relatively low water solubility.  These factors account for the common rebound of ground water concentrations. Despite high concentrations of naphthalene and methylnaphthalene in soil near the ground water table, often the dissolved  concentration in the ground water is very low.  The accumulation of these compounds at the water table causes a problem for remediation.  Frequently after ground water remediation, seasonal fluctuation of the water table through the contaminated vadose zone recharges the concentrations of these compounds.  This results in seasonal fluctuation in the ground water concentrations.

Methylnaphthalene Metabolism

The microbes in Petrox  accelerate the remediation because they product an extracellular biosurfactant that desorbs the methylnaphthalene to make it available for extraction or for in situ bioremediation.  At this site, the contaminated soil was removed to the water table, so concentrations did not rebound after the initial ground water remediation.  At other sites where Petrox bioremediation addressed methylnaphthalene or naphthalene, the consultant combined bioremediation with extraction.  The combined technologies removed the contamination flushed from the soil in addition to the bioremediation.  Click here to view case studies from other sites.

Methylnaphthalene Bioremediation

 

Nitrate and Perchlorate Bioremediation in Ground Water

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In Situ Nitrate and Perchlorate Bioremediation Eliminated Pump and Treat and Ion-Exhange Treatment Cost 

Site closure reached in less than half the projected time and cost

CL-Out® bioremediation was implemented at a confidential manufacturing site to remediate nitrate and perchlorate concentrations in soil and ground water.  The consultant installed a pump and treatment system that was operated for several years in immediate response to the discovery of contamination. While perchlorate was  the primary contaminant,  the ion-exchange resin became quickly saturated with nitrate, which was present at much higher concentrations than the perchlorate.  After review of various options and completion of a bench-scale test, the consultant implemented in situ CL-Out bioremediation to reduce the on-going cost of ground water extraction and treatment.

One of the key factors in CL-Out® cometabolism of perchlorate at this site was that CL-Out® organisms were able to reduce sequentially the oxygen and nitrate prior to perchlorate. The initial nitrate concentrations were  much higher than the perchlorate concentrations and pre-maturely saturated the ion-exchange resin. The perchlorate concentration did not decrease until the nitrate concentration decreased to less than the perchlorate concentration. One of the benefits of the CL-Out® organisms was this ability to utilize these different electron acceptors.

The initial application of CL-Out to the soil reduced the perchlorate source concentration.  After eight months of ground water bioremediation, the perchlorate concentration in the unconsolidated aquifer decreased from 128 mg/L to 3.4 mg/L immediately down gradient of the source area and from 220 mg/L to 39 mg/L farther down gradient.

Simultaneously, the CL-Out® microbes also removed the nitrate. Down gradient of the source area the nitrate concentration decreased from 105 mg/L to <1.0 mg/L.  Farther down gradient the nitrate concentration decreased from 200 mg/L to 5 mg/L.

The in situ nitrate and perchlorate bioremediation provided immediate risk reduction and mitigated potential off-site migration. The bioremediation contaminant levels to the remediation target in 3 years.  Bioremediation saved 5 years of projected treatment time and millions of dollars in OM & M costs.  The owner sold the property without environmental impairment upon completion of bioremediation. View the full case study  or  a slide presentation.

Project Consultant Received Green Leadership Award

The Massachusetts Department of Environmental Protection awarded Irwin Engineering of Natick, Massachusetts the 2016 Greener Cleanup Leadership Award for the innovative in situ bioremediation of perchorate contamination of soil and ground water at the Concord Road Site in Billerica, Massachusetts. The award honors LSPs and their clients for promoting greener cleanup principles and practices to reduce the overall net environmental footprint of hazardous waste site cleanup response actions under the Massachusetts Contingency Plan.  Read more…

Click here for more information about Sustainability and Green Remediation.

Click here for more information about CL-Out bioremediation.