Closing the loop on PFAS Treatment with Sustainable, Green options and reducing long-term Risk

R. Distefano, K. Winston
Calgon Carbon Corporation,
United States

Keywords: PFAS, PFOS, Green, activated carbon, carbon, GAC, water, sustainable, recycle, reactivation, USEPA


Background/Objectives. Per and polyfluoroalkyl substances (PFAS) have been a class of contaminants of growing concern for a number of years. Much progress has been made in the development of various treatment strategies to remove PFAS from water, especially with sorbents and membranes. Of these, granular activated carbon (GAC) is one of the most widely deployed and well-established. Additionally, a modern carbon reactivation system can produce a product that is only 20% of the carbon footprint of newly activated carbon products. A great deal of uncertainty still remains about how to effectively destroy PFAS compounds once they have been captured or separated. Carbon reactivation is a unique process, defined separately and not included in the definition of incineration or regeneration. A carbon regeneration unit is defined as “any enclosed thermal treatment device used to regenerate spent activated carbon”. Carbon reactivation is thermal treatment at high temperatures, up to 1800°F, to remove and destroy adsorbed contaminants including PFAS. During reactivation, the high temperatures employed in both the furnace and the downstream abatement system will volatilize and destroy organic compounds that were adsorbed on the GAC., it is natural to wonder if GAC reactivation can achieve high levels of destruction (i.e., ≥99.99%) of PFAS Approach/Activities. Reactivation of PFAS-laden spent carbon was conducted at a full-scale carbon reactivation facility with a third-party vendor specializing in manufacturing emissions testing, and was contracted to determine the emission rates of PFAS and hydrogen fluoride (HF) per established USEPA methodology. Results/Lessons Learned. This process demonstrated a > 99.99% destruction for total PFAS (36 PFAS list measurable) across the furnace and abatement systems. . Further, USEPA OTM-45 (air emissions) measurements were all below any state air emission levels currently in place and below any publicly available thermal oxidizer data for manufacturing sites.