In-Situ Chemical Oxidation of Pentachlorophenol Using Microbubble Perozone™ Technology
Christopher Watt, LACO Associates, CA

In-Situ 1,4 Dioxane Remediation in HVOC Sites
Andrew Brolowski, Kerfoot Technologies, Inc., Mashpee, MA

In-Situ Remediation of MTBE and Petroleum Product Spills Utilizing Ozone Injection
Scott Miller, Resource Control Corporation, Moorestown, NJ

Application of Vapor Phase Ozone to Remediate BTEX, MTBE, and EDB Groundwater Plumes
Scott M. Lato, Advanced Environmental Technologies, LLC, Tallahassee, FL

Chemical Basis for pH, Eh (Pourbaix) Changes Observed During Low-Mass Air/ Oxygen/ Ozone Injection for Petroleum Treatment
William B. Kerfoot, Kerfoot Technologies, Inc., Mashpee, MA  

Rapid Removal of Chloroethenes at Industrial Sites

Barry Culp, P.E. RMT, Inc., 100 Verdae Boulevard, Greenville, SC  29607, Tel: 864-281-0030, Fax: 864-281-0288, Email: Barry.culp@rmtinc.com 
Greg Mitchell, RMT, Inc., 100 Verdae Boulevard, Greenville, SC  29607, Tel: 864-281-0030, Fax: 864-281-0288, Email: greg.mitchell@rmtinc.com  
Steven Schroeder, RMT, Inc., 100 Verdae Boulevard, Greenville, SC  29607, Tel: 864-281-0030, Fax: 864-281-0288, Email: Steve.schroeder@rmtinc.com 
William Kerfoot, Kerfoot Technologies, Inc., 766-B Falmouth Road, Mashpee, MA  02649, Tel: 508-539-3002, Fax: 508-539-3566, Email: wbkerfoot@kerfoottech.com 

Air sparging with trenches had failed to remove groundwater and soil contamination at a superfund site in Piedmont soils in South Carolina.  The major contaminants to be removed were 1,2 Dichloroethene (DCE) and Trichloroethene (TCE).  A costing of alternatives showed that life cycle costs of using microbubble ozone would be the lowest cost choice when compared with groundwater pump and treat, air sparging, and liquid oxidation (permanganate).  In spring 2001, field pilot studies were performed to verify expected removal rate and injection well radius of influence.  Initial testing for 12 weeks on two ozone sparging wells showed over 50% removal.  During 2001-2002, full-scale design and construction was completed with nine ozone microbubble sparging wells with recirculation capability.  In October 2002 the system was started.  After 12 months of treatment, all monitoring wells but one were at recommended MCLs (minimum concentration limits).  After 18 months of treatment, all wells met closure requirements.  Continued monitoring showed no rebound.

A Western Massachusetts site is ongoing with chloroethene treatment by ozone and Perozone™.  Different approaches to contaminant removal were required at two soil regions on the site.

In-situ Chemical Oxidation of Pentachlorophenol Using Microbubble Perozone Technology

Christopher Watt, LACO ASSOCIATES, 21 West Fourth Street, CA, 95501, Tel: 707-443-5054, Fax: 707-443-0553, Email: wattc@lacoassociates.us

A proprietary ozone and hydrogen peroxide sparging system was operated for 10 months at a former lumber mill located on the margin of an estuarine environment.  Target compounds, intrinsic groundwater parameters, and chloride ion were monitored in the area groundwater.  In addition, pre and post-treatment intrinsic soil conditions were documented.

The strongly poised (up to 1% organic carbon and 2.5% ferric iron by weight) water-logged sediments resisted change in electron pressure (oxidation-reduction potential) during oxidant sparging.  This elevated reduction capacity appeared to limit effective distribution of the oxidants. Increased injection times and installation of additional sparge points allowed for sufficient oxidant distribution.

After nearly one year of treatment, dissolved chlorophenol concentrations were reduced 95% and soil sampling has confirmed the gradual destruction of sorbed-phase chlorophenols.

In-Situ 1,4 Dioxane Remediation in HVOC Sites

William B. Kerfoot, Kerfoot Technologies, Inc., 766-B Falmouth Road, Mashpee, MA  02649, Tel: 508-539-3002, Fax: 508-539-3566, Email: Wbkerfoot@kerfoottech.com
Andrew Brolowski, Kerfoot Technologies, Inc., 766-B Falmouth Road, Mashpee, MA  02649, Tel: 508-539-3002, Fax: 508-539-3566, Email: andrew.brolowski@kerfoottech.com

Increasingly, 1,4 Diethylene Dioxide (1,4 Dioxane) is being found as a co-contaminant at chloroethene spill sites.  The highly soluble compound has been employed as a solvent for lacquers, paints, and varnishes and as a corrosion inhibitor.  The compound has shown limited removal (<5% to 30% TOC) during biodegradability tests.  Bench-scale testing has shown good removal (69-78%) with exposure to microbubble ozone or peroxide-coated ozone injected into aqueous soil slurries while in the presence of elevated chloroethene concentrations.

The bench-scale tests were conducted in a pressurized glass reaction cell enclosed in a vented chamber.  Gas and liquid were introduced with a miniaturized Laminar Spargepoint®.  A slurry solution was maintained in suspension with stirring by a Teflon-coated bar.  Aqueous subsamples were removed at the beginning of the test and at 120, 240, and 480 minutes following the start of the test. 

The bench-scale tests revealed a removal rate of about 0.15% per minute, thus effective for in-situ treatment.  Field tests of 1,4 Dioxane removal with Perozone™ have exhibited similar effective treatment.  Examples of observed attenuation rates will be discussed.

In-Situ Remediation of MTBE and Petroleum Product Spills Utilizing Ozone Injection

Scott Miller, Resource Control Corporation, 1274 N. Church Street, Moorestown, NJ  08057, Email: scottm@rcc-net.com
Paul Rosenwinkel, Resource Control Corporation, 1274 N. Church Street, Moorestown, NJ  08057, Email: paulr@rcc-net.com
Jeffrey Dey, Resource Control Corporation, 1274 N. Church Street, Moorestown, NJ  08057, Email: jeffd@rcc-net.com

Numerous gasoline and oil spill sites located in New Jersey and Pennsylvania have been remediated using ozone injection either as a primary technology or by bundling ozone injection with more conventional remedial technologies including total phase extraction (TPE) or air sparging and soil venting AS/SVE).  The bulk of the petroleum mass in the source area were remediated within the first two quarters using TPE or SVE.  Soil and groundwater were then addressed via air, oxygen and ozone injection as a gas or suspended in re-circulated groundwater.  Remediation has commonly been achieved in 6 to 18 months of active treatment.

MTBE (Methyl-tert butyl-Ether) have been detected at these sites at dissolved concentrations up to 100,000 ug/L along with BTEX dissolved compound concentrations, up to 43,000 ug/L, (Benzene, Toluene, Ethylbenzene, Xylenes).  TBA has also been detected at dissolved concentrations as high as 180,000 ug/L.  When using the combined technology approach (ozone combined with TPE or AS/SVE) hydrocarbon reductions have been more efficient than predicted by stoichiometry (direct reaction of O2/O3).  Efficient site remediation results have been achieved at ozone to contaminant ratios observed from 1.1:1 to 1.8:1 (ratio of oxidant-to-contaminant) whereas stochimotry predicts ratios closer to 3:1.   The lithology of sites was different, including clean sand, saprolites and weathered schist.  Site closure standards for MTBE, BTEX, and TPH are commonly met on sites within one year’s time.

Application of Vapor Phase Ozone to Remediate BTEX, MTBE, and EDB Groundwater Plumes

Scott M. Lato, P.E., Advanced Environmental Technologies, LLC, 1264 Timberlane Rd., Tallahassee, FL 32312, Tel: 850-385-2010, Fax: 850-385-2423, Email: slato@aetllc.com

Advanced Environmental Technologies, LLC performed a multi-depth Ozone injection pilot test on the groundwater at a petroleum impacted site in Quincy, FL, under the Florida Department of Environmental Protection’s (FDEP) Petroleum Pre-Approval Program.

The subject facility is located in Quincy, Florida approximately 25 miles west of Tallahassee, FL, has been a gasoline station since at least 1977.  This facility dispensed unleaded and leaded gasoline as well as diesel fuel from three 4,000 gallon, and one 6,000 gallon underground storage tanks (USTs).  This facility has been in the FDEP’s cleanup program for at least 15 years, with the first Contamination Assessment done in 1990, followed by a Remedial Action Plan in 1992, implementation of the groundwater pump & treat system in 1994, additional assessment in 1996-1997, a Remedial Action Plan Modification, for additional groundwater extraction and multiphase wells, in 1998, followed by a vapor extraction pilot test, with the full-scale re-implementation in 2001.  The current remedial system was in operation for approximately two years until AET took over as the cleanup consultant in 2002.  Prior to 2002, over $866,000 had already been spent to rehabilitate this site. 

Based upon the system performance, existing contamination plume, vapor extraction off-gas concentrations and overall poor physical condition of the remedial system, AET in conjunction with the FDEP decided to perform additional site assessment activities.  The most recent vadose zone site assessment data was at least 5-6 years old at the time.  This new data indicated that the petroleum impacted groundwater plume was still significantly large with concentrations as high as 55,900 ppb BTEX with a residual petroleum source in the vadose zone with concentrations as high as 629 and 161 mg/kg  26 to 28 and 42 to 44 ft below land surface, respectively.

Using the “post 10 year remediation” data, AET developed a plan to perform an ozone injection pilot test to address the petroleum impacted groundwater at this site.  The dual-zone injection well was placed in a location as close to the source area as possible, due to an existing canopy.  In addition, the injection well was situated so that existing monitoring and recovery wells could be utilized as observation points at varying distances.

The pilot test setup, equipment, pre, interim and post groundwater sampling event data and analysis will be presented, including illustrations of radius of influence of both DO and ORP, groundwater concentration trends, rate of decay model development and rate of desorption as well as plans for full scale implementation.

Chemical Basis for pH, Eh (Pourbaix) Changes Observed During Low-Mass Air/Oxygen/Ozone Injection for Petroleum Treatment

William B. Kerfoot, Kerfoot Technologies, Inc., 766-B Falmouth Road, Mashpee, MA  02649, Tel: 508-539-3002, Fax: 508-539-3566, Email: wbkerfoot@kerfoottech.com 

Low-mass aqueous reactions during oxidation of petroleum hydrocarbons yield CO₂ and slightly rising pH, now lowering pH.  Even microbubble ozone treatment of several chlorinated compounds (PCE, TCE, DCE) with aqueous concentrations up to 2,000 ppb often show increasing alkalinity and pH.  Because the addition of ozone produces numerous reactions at the same time, generating both H⁺ and OH⁻, the pH does not change significantly.  Measurement of bicarbonate alkalinity while oxidizing on chloroethene or PCP sites can predispose the impending pH change.  The addition of CO₂ from both air and end product oxidation reactions yields an equilibrium mixture of bicarbonates and carbonates which moves the groundwater system toward pH 8. 

Oxidation states rise from reducing conditions to about 200 mv during remedial operations, substantially less than the 400 mv level likely to promote trivalent (3⁺) chromium conversion to hexavalent (6⁺) chromium.  The increase in oxidation potential causes the precipitation of some soluble iron and manganese, coprecipitating other transition metals.  The total mass of ferrous iron (Fe²⁺) precipitated, even from 20 ppm initial levels, represents only 1/80,000 of existing soil mass and is not a threat to “plug” the aquifer.

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