Soil Mixing Using In Situ Chemical Oxidation Reduces Contamination Concentrations at Former Dry Cleaning Facility

Regenesis Remediation Services (RRS) was hired for this large-scale soil mixing project to treat tetrachloroethylene (PCE) in shallow surface soils. The application used in situ chemical oxidation (ISCO) technology to oxidize residual chlorinated solvents at this former dry cleaner site. The goal was to reduce chlorinated volatile organic compounds (cVOCs), particularly PCE, from >20 ppm to less than 5 ppb. The design of the project was divided into a grid with twelve sections, each 25 feet (ft.) by 21.5 ft., and 5 ft. deep.

Using RegenOx® remediation chemistry and an excavator to complete the soil mixing, the impacted soils were removed by an excavator and a proportional amount of RegenOx was evenly dispersed throughout the excavated soil, then thoroughly mixed using the excavator.

Once mixing was complete, the soils were placed back into the treatment cell while being hydrated with a RegenOx solution made up of RegenOx, water and hydrogen peroxide. By optimizing the contact between the soil, contaminants, and RegenOx, powerful desorption effects strip PCE off of the soil matrix and onto the RegenOx catalytic surface. This catalytic surface contributes to localized free-radical generation, leading to focused and efficient contaminant destruction via soil mixing. After eight days of the completion of the project, 98-100% reductions were achieved in the twelve sections of the grid.

Download PDF