A mechanical system was employed to mix unsaturated or saturated contaminated soils while simultaneously injecting treatment or stabilization agents. Depths of 40 feet can be achieved with this equipment. The 10-foot mixing diameter was used for this demonstration. Treatment agents were injected through a vertical, hollow shaft and out into the soil through 0.25 or 0.50 in.
Treatment is achieved in butted or overlapped soil columns.
The ground surface above the mixed region was covered by a 14-ft. The off-gas treatment system consisted of activated carbon filters followed by a HEPA filter. Removal of VOCs was enhanced by moving the mixing auger up and down from 2 to 15 ft. below ground surface during vapor stripping. For the demonstration, a total of 14 soil columns, each 10 ft. in diameter, were treated. Each of the four treatment processes were demonstrated in three soil columns, each 15 ft. deep.