In Situ Chemical Oxidation Reduces Contamination Concentrations at a Former Dry Cleaner Site

Regenesis Remediation Services (RRS) was contracted to design and perform in situ chemical oxidation (ISCO) via soil mixing to remediate tetrachloroethylene (PCE) impacted soil at a former dry cleaner site located in Cook County, Illinois. RegenOx® was chosen as the primary remediation technology for the chemical oxidation. The treatment area focused on soilbound PCE contamination around 1,170 mg/kg in the clay-rich unsaturated soils. The soil remediation objective was to reduce PCE levels below the 240 mg/kg soil saturation limit established by the Illinois EPA.

The impacted soils were removed by a mini trackhoe excavator and placed inside a vacant unit adjacent to a treatment cell where the soil mixing was performed. A proportional amount of RegenOx was evenly dispersed throughout the excavated, contaminated 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.

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. Approximately 242 cubic yards of soil bound contaminant mass was successfully treated at this site. Soil mixing was performed from surface grade to approximately 10 feet below grade.

Download PDF