Potential of pneumatic fracturing to enhance in situ remediation technologies
Pneumatic fracturing is an in-situ process which enhances the removal and treatment of hazardous organic contaminants from the vadose zone. Its purpose is to reduce treatment time of contaminated formations, and extend available technologies to more difficult geologic conditions. The pneumatic fracturing process consists of injecting air or other gases into contaminated geologic formations at controlled flow rates and pressures. The process enhances apertures in the formation in a predominantly horizontal direction from the point of injection. This minimizes the potential for vertical transport within the formation. The potential benefits of pneumatic fracturing depend on the type of soil or rock being treated. In fine-grained soils, such as silts and clays, pneumatic fracturing increases the permeability of the formation. In coarse-grained soils, the process provides a means for rapidly aerating the formation. In sedimentary rock formations, pneumatic fracturing can widen the aperture of existing discontinuities and clear away soil in the aperture. Pneumatic fracturing can be integrated with a number of in-situ technologies including vapor extraction, bioremediation, soil flushing, and thermal treatment. Field testing has confirmed the feasibility of pneumatic fracturing to enhance remediation of the vadose zone. Measurement of residual ground surface heave and increased flow rates after injection confirm the existence of new conductive channels. Field studies also show that pneumatic fractures remain viable for extended periods. It is anticipated that the pneumatic fracturing process is capable of injecting both low and high permeability formations with microorganisms, nutrients, and large volumes of selected gases to encourage microbial growth.
- Research Organization:
- Arizona Univ., Tucson, AZ (United States). Coll. of Engineering and Mines; New Mexico State Univ., University Park, NM (United States); Waste-Management Education and Research Consortium (WERC), Las Cruces, NM (United States); USDOE, Washington, DC (United States)
- OSTI ID:
- 121027
- Report Number(s):
- CONF-940225--Vol.2
- Country of Publication:
- United States
- Language:
- English
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