dnapls Articles

  • Bioremediation of DNAPL

    Dense non-aqueous phase liquid (DNAPL) are mixtures of organic compounds that when combined have a specific density greater than water, which has a specific density of 1.00. They sink through water and form a separate liquid phase below the water. DNAPL mixtures can include compounds such as chlorinated solvents, PCB oils, coal tars, and creosotes (complex mixtures consisting of polycyclic ...

  • DNAPL in Clay Formation

    PROJECT BACKGROUND At a manufacturing site located in Cookeville, TN, on and offsite soil (tight clays) and groundwater contaminated with chlorinated solvents, were discovered as the result of a Phase I and a Phase II investigation. The client entered the State of Tennessee Voluntary Clean-up Oversight and Assistance Program (VCOAP), which resulted in an informal focused feasibility study to ...


    By REGENESIS

  • DNAPL recovery made easy

    Recovering DNAPL (Dense Non Aqueous Phase Liquid) product is never an easy task. Recovering an extremely viscous DNAPL, such as coal tar, can be a nightmare. With viscosity approaching 20,000 ssu at ambient temperatures, devices that need hydrophobic screens become useless; however, the solution is simple – a PetroXtractor® belt oil skimmer made by Abanaki Corporation, Chagrin Falls, Ohio. ...


    By Abanaki Corporation

  • Portland, Or - Deep, DNAPL remediation

    In 1999, the senior managers of Thermal Remediation Services, Inc (TRS) while working for a former employer, as a subcontractor to AMEC, provided Electrical Resistance Heating (ERH) for VOC-impacted groundwater at a commercial site in Portland, Oregon. The remediation was conducted under the Oregon Department of Environmental Quality (DEQ) Voluntary Cleanup Program. The remedial action objective ...


    By TRS Group, Inc.

  • Deep, DNAPL remediation Portland, OR

    In 1999, the senior managers of TRS Group, Inc (TRS) while working for a former employer, as a subcontractor toAMEC, provided Electrical Resistance Heating (ERH) for VOC-impacted groundwater at a commercial site in Portland,Oregon. The remediation was conducted under the Oregon Department of Environmental Quality (DEQ) Voluntary Cleanup ...


    By TRS Group, Inc.

  • Successful Biostimulation Treatment of TCE DNAPL

    The challenges posed by the presence of DNAPL are rooted in the unpredictable manner in which it spreads and moves through the subsurface, and the fraction of total contaminant mass it represents in an associated groundwater plume via sorbed, residual and drainable phases (typically greater than 99 percent). Under natural conditions, the dissolution of DNAPL is very slow, allowing groundwater ...


    By Arcadis

  • Extraction well design for DNAPL recovery.

    The potential for downward migration of dense nonaqueous phase liquid (DNAPL) into deeper portions of a saturated hydrogeologic unit has important implications for successful groundwater remediation. Little information has been published regarding the design of extraction wells that allow DNAPL recovery without simultaneously creating a conduit for cross contamination by vertical migration ...


    By Hargis + Associates Inc

  • The DNAPL Remediation Challenge: Is There a Case for Source Depletion?

    Untitled Document Executive Summary Introduction Releases of Dense Non-Aqueous Phase Liquids (DNAPLs) at a large number of public ...


  • Ivey-sol • SPT DNAPL - case study

    Ivey-sol • SPT Technology was successfully used to remediation of a commercial dry-cleaning facility. The subject facility had been in operational since ca. 1971. The DNAPL contamination was comprised of DCE (Dichloroethylene) and TCE (Trichloroethylene) dry-cleaning solvents. Some minor Brominated compounds were also detected. The impacts were limited to the soil and groundwater under the ...


    By Ivey International Inc.

  • Combining thermal treatment with MNA at a brownfield DNAPL site

    Abstract A heavily contaminated Brownfields site in New York was remediated and redeveloped using a combination of In-Situ Thermal Desorption and Monitored Natural Attenuation. Four source areas were addressed by the thermal technology, and groundwater beneath the site is undergoing natural attenuation. Approximately 86,000 lbs of volatile organics were extracted and treated on-site. The ...


    By TerraTherm, Inc.

  • Leaks and spills - LNAP and DNAPL detection and clean up

    Any tank can leak. Most leaks can be cleaned up and responsible operators need equipment that does what’s needed. With an ATEX Zone 0 certified interface meter site operators can successfully achieve LNAP and DNAPL detection when monitoring petrochemical sites, tank farms, petrol station forecourts, landfills or remediation sites. If site technicians detect ...


    By Geotech

  • Thermal treatment of thick peat layers – DNAPL removal and shrinkage

    Abstract A PCE DNAPL source zone was treated using thermal conduction heating combined with multi-phase extraction. Thick peat layers, even when contaminated with PCE DNAPL, were remediated to average soil PCE concentrations of 0.17 mg/kg (99.6% reduction compared to starting levels). This was accomplished in 83 days of heating, by elevating the temperature to the boiling point of water, and ...


    By TerraTherm, Inc.

  • DNAPL removal action alameda navy base, Alameda California

    TRS Group, Inc (TRS), as a subcontractor to Shaw Environmental & Infrastructure, provided a Six Phase Heating(SPH) remediation of Plume 4-2 at the Alameda Navy Base. Plume 4-2 soil and groundwater has been impacted by aDNAPL consisting of vinyl chloride, DCA, DCE, TCA, TCE, and PCE. Also present were the daughter products of thesecompounds. At the Alameda Navy Base, these contaminants are ...


    By TRS Group, Inc.

  • In Situ Thermal Remediation of DNAPL and LNAPL Using Resistance Heating

    Electrical resistance heating (ERH) is an in situ thermal treatment for soil and groundwater remediation that can reduce the time to clean up volatile organic compounds (VOCs) from years to months. The technology is now mature enough to provide site owners with both performance and financial certainty in their site-closure process. The ability of the technology to remediate soil and groundwater ...


    By TRS Group, Inc.

  • Optimization design based on ensemble surrogate models for DNAPLs-contaminated groundwater remediation

    The optimization design of surfactant-enhanced aquifer remediation for dense non-aqueous phase liquids (DNAPLs)-contaminated groundwater is proposed through integrating simulation and optimization models. Many studies have demonstrated that the surrogate model is an effective tool for building a bridge between simulation and optimization models. In this paper, the simulation model was first ...


    By IWA Publishing

  • Using Treatment Train to Optimize DNAPL Source Zone Remediation

    Many DNAPL sites have been treated using innovative source reduction technologies, such as in situ chemical oxidation (ISCO). Although individual technologies can be successful in removing significant mass from a DNAPL source, rarely, if ever, will implementation of a single technology achieve site closeout. More often, a combination of technologies sequenced throughout the life cycle of a ...


    By CH2M Hill Companies, Ltd.

  • DNAPL Characterization Methods and Approaches, Part 1: Performance Comparisons

    Contamination from the use of chlorinated solvents, often classified as dense nonaqueous phase liquids (DNAPLs) when in an undissolved state, represents an environmental challenge with global implications. Mass-transfer limitations due to rate-limited dissolution can lead to long-term aquifer persistence for even small volumetric fractions. The identification of DNAPL source zones located beneath ...


    By QED Environmental Systems

  • ISCR-Enhanced Bioremediation of a TCE DNAPL Source Utilizing EHC® and KB-1®

    Remediation of chlorinated solvent DNAPL sites often meets with mixed results. This can be attributed to the diametrically opposed nature of the impacts, where the disparate dissolved phase plume is more manageable than the localized, high-concentration source area. A wide range of technologies are available for downgradient plume management, but the relative mass of contaminants in a ...


  • Analysis of DNAPL Source-Depletion Costs at 36 Field Sites

    A recent U.S. Environmental Protection Agency (US EPA) expert panel on dense nonaqueous phase liquid (DNAPL) remediation concluded that uncertainty in the costs and benefit of applying source-depletion technologies (i.e., active remediation in source zones) is one key factor that discourages widespread use of these technologies at DNAPL sites (Kavanaugh et al., 2003). To reduce this uncertainty, ...


  • Surfactant enhanced in-situ remediation of DNAPL impacted soil and groundwater - Montreal refinery

    Abstract A Montreal chemical refinery reduced the dichlorobenzene and other dense non-aqueous phase liquid (DNAPL) impacts on the soil and groundwater where a railway line is adjacent to an above ground storage tank farm. Ivey-sol® surfactant mixtures were injected three times during a two week pilot test, into a series of in-situ wells. The soil and groundwater matrix experienced ...


    By Ivey International Inc.

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