Liquified propane solvent is typically used to treat soils, sludges, and sediments, while liquified carbon dioxide is typically used to treat wastewater. Typically, more than 99 percent of the organics are extracted from the feed. After the solvent and organics are separated from the treated feed, the solvent and organic mixture passes to the solvent recovery system. Once in the solvent recovery system, the solvent is vaporized and recycled as fresh solvent. The organics are drawn off and either reused or disposed of.
Treated feed is discharged from the extraction system as a slurry in water.
This process can also treat refinery wastes and wastewater contaminated with organics. Initial analytical data shows that treatment achieved levels of residual PCBs well below the 1 ppm cleanup level required for site closure. CF Systems Corporation completed the first commercial on-site treatment operation at Star Enterprise, in Port Arthur, Texas. The unit operated continuously from March 1991 to March 1992 and was on-line more than 90 percent of the time. Following heavy metals fixation, the treated solids were disposed of in a Class I landfill.