“Novel Cyclodextrin-Based Adsorbents to Remove Per- and Polyfluoroalkyl Substances from Water” by Dr. Damian Helbling (SERDP Project Webpage)

AFFF (aqueous film-forming foam) formulations have been used for decades to suppress hydrocarbon fuel-based fires at Department of Defense facilities. PFAS are key constituents of AFFF, and PFAS occurrence in groundwater at many of DoD facilities has been widely reported. Developing cost-effective remediation strategies to remove PFAS from groundwater is challenging. As part of this SERDP-funded effort, we have developed a promising class of cyclodextrin-based adsorbents that can be rationally designed to target specific types of pollutants. This webinar highlighted the evolution of our cyclodextrin-based adsorbents and describe current advances in this emerging technology. We have optimized these adsorbents to obtain high affinity for a variety of PFAS including those with varying chain length, hydrophilic head groups and charge state. We have characterized the performance of these adsorbents in a variety of groundwater matrices and have benchmarked their performance against a variety of more conventional adsorbent materials. A startup company has been formed to manufacture and commercialize the most promising cyclodextrin-based adsorbents for implementation in groundwater remediation processes. 

“Assessment, Optimization, and Demonstration of PFAS-Free AFFF alternatives against Military Specifications” by Dr. Satya Chauhan (ESTCP Project Webpage)

This ESTCP-funded project is aimed at experimentally determining where commercial, off-the-shelf (COTS), PFAS-free foam formulations fall short of stringent military specifications (MIL-PRF-24385F) and to determine if alternative PFAS-free foam-delivery firefighting technology and/or minor chemical modifications can improve their performance. 

Although there are many PFAS-free COTS foams available, none have been shown to meet the Mil Spec, especially the performance specifications for fire extinguishment time. PFAS-containing foams (AFFF) are expected to be phased out beginning in October 2023, per the 2020 National Defense Authorization Act. Therefore, identifying workable foam replacements is critical. This project focused on optimizing and demonstrating firefighting performance employing CAF and UHP foam-delivery systems. These commonly available firefighting engineering technologies have been shown to improve foam quality, which is expected to reduce the fire extinguishment time and increase the burnback time. The webinar presented initial test results which show promise towards meeting DoD goals of eliminating fluorinated compounds in fire suppressants for fighting Type-B (hydrocarbon) fires.