A study of air flow through saturated porous media and its applications to in-situ air sparging

The efficiency of an in situ air sparging system is controlled by the extent of contact between injected air and contaminated soil and pore fluid. Characterizing the mechanisms governing air propagation through saturated porous media is therefore critical to the design of an effective cleanup treatment. The objectives of this investigation were thus to identify and to quantify the parameters that affect the advancement of an air front through saturated soils. To this end, an experimental program was conducted in order to assess the impact of: 1) operational parameters, specifically the differences in air propagation as a result of injection under constant pressures and constant flow rate conditions, as well as the impact of injector geometry; and 2) medium properties, namely hydraulic conductivity and pore fluid characteristics. Experiments were conducted in a geotechnical centrifuge, which made it possible to test under a wide range of injection pressures while maintaining both realistic fluid and soil pressures, and sample stability. Experimental results show that air propagation characteristics through saturated soils are primarily controlled by two factors, the pressure in the air phase and the hydraulic conductivity of the medium. Under constant pressure injection, the magnitude of the pressure gradient between air and pore fluid dictates the final shape of the air plumes. Under constant flow rate injection, the relationship between the rate of air inflow and of pore fluid outflow determines the volume available for air invasion, and consequently,

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Civil and Environmental Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2001

Author dc:creator

• Marulanda, Catalina, 1971-

Advisor dc:contributor.advisor

• Patricia J. Culligan.

• Civil and Environmental Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/8253

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8253