Physical modeling of air-sparging technique for groundwater remediation

Air sparging is one of the most efficient techniques to remedy saturated soils and groundwater contaminated with voltaic organic compounds.Based on the model tests,the air flow pattern and the zone of influence(ZOI) were investigated for air sparging process in different types of soil mass.It was shown that the minimum sparging pressure was dependent on the hydro-static pressure and capillary pressure of soil mass;in gravel mass air traveled in bubbles and ZOI was of a parabolic shape;in fine sand mass air flowed in discrete,stable micro-channels and ZOI was larger than those in gravel mass under the same sparging pressure;there was a positive influence of pulsating sparging in sands while it was insignificant in gravels.