Perfluorinated compounds (PFCs)
KEMRON’s Applied Technologies Group performed an ex-situ thermal remediation bench scale treatability study on soil which was impacted with compost impacted with Perfluorinated compounds (PFCs). Common PFCs include perfluorooctanoic acid (PFOA), used to make fluoropolymers such as Teflon, among other applications; or perfluorooctanesulfonic acid (PFOS), used in the semiconductor industry, 3M’s former Scotchgard formulation, and 3M’s former fire-fighting foam mixture; or perfluorononanoic acid (PFNA), used as surfactant in the emulsion polymerization of fluoropolymers; or perfluorobutanesulfonic acid (PFBS), used as a replacement for PFOS in 3M’s reformulated Scotchgard; or perfluorooctanesulfonyl fluoride (POSF), used to make PFOS-based compounds; or perfluorooctanesulfonamide (PFOSA), formerly used in 3M’s Scotchgard formulation; and FC-75, a 3M Fluorinert liquid; and perfluorinated cyclic ether (PFCE).
The treatability study was performed to determine the treatment temperatures potentially capable for thermal destruction of PFCs in highly organic soil at the site. The site test material consisted of highly organic soil which had been composted at different decomposing time intervals. Four candidate site materials with decomposition times of 3, 6, 12, and 18 months were subjected to thermal treatment performed at three target temperatures and one retention time. The materials in the study were initially heated to 100 Celsius to completely remove all moisture prior to subjecting the material to the target temperatures of 200, 398, and 1,100 degrees Celsius. Treatment durations were approximately 15 minutes at the target treatment temperature. Throughout treatments KEMRON performed constant temperature monitoring of the soil. All vapors were passed through an activated carbon off-gas treatment prior to releasing into the atmosphere.
KEMRON was not provided with the results of PFC analyses conducted on the treated test materials. However, discussions with the client indicated that treatment temperatures in excess of 1,000C showed successful reductions in total PFC concentrations.