This study is a laboratory test of the aquifer remediation concept proposed by Gvirtzman and Gorelick (1992, Transp. Porous Media, 8: 71-92), which involves the removal of volatile organic compounds (VOCs) dissolved in groundwater. The principle is to inject air into a well, creating air-lift pumping, which is used as a means of in-well vapor stripping. The partially treated water is separated from the VOC vapor and infiltrates back to the water table. A laboratory-scale aquifer model containing a remediation-well prototype was used to trace VOC removal over time. The removal rates of trichloroethylene (TCE), toluene and chloroform were monitored using eight triple-level observation wells. The continuous decrease of VOC concentrations in space and time was interpreted based on three processes: (1) the diffusional mass transfer between the contaminated water and the air bubbles during their rise within the well; (2) the desorption of VOCs from the solid matrix to the water phase; (3) the flow field in the saturated zone driven by the continuous water circulation between the pumping well and the recharging area. In a companion paper (Pinto et al., 1997), three-dimensional flow and transport modeling with inter-phase mass transfer is carried out to simulate these processes.
Bibliographical noteFunding Information:
This research was carried out as part of the MSc. research of the first author under the supervision of the second author at the Institute of Earth Sciences at the Hebrew University of Jerusalem, Israel. We thank Mrs. B. Katz for reviewing the manuscript. The research was supported by grants from the Zvi Herman Schapira Research Fund of the Hebrew University of Jerusalem, and the Water Commission of the Israel Ministry of Agriculture.
- Air-lift pumping
- Vapor stripping