Contamination removal rates in pulsed and steady-flow aquifer sparging

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:467736

Payne, F C; Blaske, A R; VanHouten, G A ^[1]

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1. ETG Environmental, Inc., Lansing, MI (United States)

A field experiment was conducted to determine whether pulsed-injection aquifer sparging induced greater mass transfer of trichloroethylene (TCE) than steady-flow sparge air injection in the same location. Current literature indicates that, despite an increase in air-water interfacial surface area induced by sparge air injection, mass transfer of volatile contaminants from aqueous to gaseous phase is limited by aqueous-phase diffusion rates. It was hypothesized that pulsed sparge air injection would induce bulk water movement, minimizing the mass transfer rate limitation caused by aqueous-phase diffusion. This effect was expected to be observed through an increase in the rate of TCE concentration reductions as the experimental system shifted from steady to pulsed-flow operation. Experimental results showed highly variable groundwater TCE concentrations during steady-flow operations. Average TCE concentrations increased slightly during the steady-flow trials at both 1.5- and 3.0-m radial distances from the sparge well, but the increases were not significant. During the pulsed-flow trial, a significant decline in TCE concentrations was observed at the 1.5-m radius. At the 3.0-m radius, a slight decline was observed, which was not significant.

• OSTI ID: 467736
• Report Number(s): CONF-950483--; ISBN 1-57477-003-9
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AQUIFERS
BIODEGRADATION
CHLORINATED ALIPHATIC HYDROCARBONS
GAS INJECTION
IN-SITU PROCESSING
REMEDIAL ACTION