EET, INC.

(TechXtract® Process)

TECHNOLOGY DESCRIPTION:

The TechXtract® process employs proprietary chemical formulations in successive steps to remove polychlorinated biphenyls (PCB), toxic hydrocarbons, heavy metals, and radionuclides from the subsurface of porous materials such as concrete, brick, steel, and wood. Each formulation consists of chemicals from up to 14 separate chemical groups, and each formulation can be specifically tailored to each contaminated site.

The process is performed in multiple cycles. Each cycle consists of three stages: surface preparation, extraction, and rinsing. Each stage employs a specific chemical mix.

The surface preparation step uses a solution that contains buffered organic and inorganic acids, sequestering agents, wetting agents, and special hydrotrope chemicals. The extraction formula includes macro- and microemulsifiers in addition to electrolyte, flotation, wetting, and sequestering agents. The rinsing formula is pH-balanced and contains wetting and complexing agents. Emulsifiers in all the formulations help eliminate fugitive releases of volatile organic compounds or other vapors.

The chemical formulation in each stage is sprayed on the contaminated surface as a fine mist and worked into the surface with a stiff bristle brush or floor scrubber. The chemicals are allowed to penetrate into the subsurface and are then rinsed or vacuumed from the surface with a high-efficiency, particulate air-filtered, barrel-vacuum. No major capital equipment is required.

Contaminant levels can be reduced from 60 to 90 percent per cycle. One cycle can take up to 24 hours. The total number of cycles is determined from initial contaminant concentrations and final concentration target levels.

WASTE APPLICABILITY:

The TechXtract® process is designed to treat porous solid materials contaminated with PCBs; toxic hydrocarbons; heavy metals, including lead and arsenic; and radionuclides. Because the contaminants are extracted from the surface, the materials can be left in place, reused, or recycled. After treatment, the contaminants are concentrated in a small volume of liquid waste.

In commercial applications, the process has reduced PCB concentrations from 1,000,000 micrograms per 100 square centimeters (µg/100 cm²) to concentrations less than 0.2 µg/100 cm². The TechXtract® process has been used on concrete floors, walls and ceilings, tools and machine parts, internal piping, valves, and lead shielding. The TechXtract® process has removed lead, arsenic, technetium, uranium, cesium, tritium, and thorium.

STATUS:

This technology was accepted into the SITE Demonstration Program in summer 1994. EET, Inc.'s (EET) demonstration is on hold pending site selection and notice to proceed by EPA.

The technology has been used in over 200 successful decontamination projects for the U.S. Department of Energy; U.S. Department of Defense; the electric, heavy manufacturing, steel, and aluminum industries; and other applications. Further research is underway to apply the technology to soil, gravel, and other loose material. EET also plans to study methods for removing or concentrating metals in the extracted liquids.

FOR FURTHER INFORMATION:

EPA PROJECT MANAGER:
Dennis Timberlake
U.S. EPA
National Risk Management Research
Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
513-569-7547
Fax: 513-569-7676

TECHNOLOGY DEVELOPER CONTACT:
Michael Bonem
EET, Inc.
4710 Bellaire Boulevard, Suite 300
Bellaire, TX 77401
713-662-0727
Fax: 713-662-2322