(Pneumatic Fracturing ExtractionSM and Catalytic Oxidation)
Accutech Remedial Systems, Inc. (Accutech), and the Hazardous Substance Management Research Center at the New Jersey Institute of Technology in Newark, New Jersey have jointly developed an integrated treatment system that combines Pneumatic Fracturing Extraction (PFESM) with catalytic oxidation. According to Accutech, the system provides a cost-effective, accelerated approach for remediating less permeable formations contaminated with halogenated and nonhalogenated volatile organic compounds (VOC) and semivolatile organic compounds (SVOC).
The Accutech system forces compressed gas into a geologic formation at pressures that exceed the natural in situ stresses, creating a fracture network. These fractures allow subsurface air to circulate faster and more efficiently throughout the formation, which can greatly improve contaminant mass removal rates. PFESM also increases the effective area that can be influenced by each extraction well, while intersecting new pockets of contamination that were previously trapped in the formation. Thus, VOCs and SVOCs can be removed faster and from a larger section of the formation.
PFESM can be combined with a catalytic oxidation unit equipped with special catalysts to destroy halogenated organics (see photograph below). The heat from the catalytic oxidation unit can be recycled to the formation, significantly raising the vapor pressure of the contaminants. Thus, VOCs and SVOCs volatilize faster, making cleanup more efficient.
Pneumatic Fracturing ExtractionSM and Catalytic Oxidation
PFESM can also be combined with hot gas injection (HGI), an in situ thermal process, to further enhance VOC and SVOC removal rates. HGI returns to the ground the energy generated during catalytic oxidation of the VOCs.
The Accutech system can remove halogenated and nonhalogenated VOCs and SVOCs from both the vadose and saturated zones. The integrated treatment system is cost-effective for treating soils and rock when less permeable geologic formations limit the effectiveness of conventional in situ technologies.
According to Accutech, the PFESM-HGI integrated treatment system is cost-effective for treating less permeable soil and rock formations where conventional in situ technologies have limited effectiveness. Activated carbon is used when contaminant concentrations decrease to levels where catalytic oxidation is no longer cost-effective.
The Accutech technology was accepted into the SITE Demonstration Program in December 1990. The demonstration was conducted in summer 1992 at a New Jersey Department of Environmental Protection and Energy Environmental Cleanup Responsibility Act site in Hillsborough, New Jersey. During the demonstration, trichloroethene and other VOCs were removed from a siltstone formation.
Results of this demonstration were published in the following documents available
from EPA:
The demonstration results indicate that PFESM increased the effective vacuum radius of influence nearly threefold. PFESM also increased the rate of mass removal up to 25 times over the rates measured using conventional extraction technology.
TECHNOLOGY DEVELOPER CONTACT:
John Liskowitz
Accutech Remedial Systems, Inc.
Cass Street at Highway 35
Keyport, NJ 07735
908-739-6444
Fax: 908-739-0451