Formatted Title
Pilot-Scale PFAS Separations and Transformations: State of the Science and Lessons Learned
Background/Objectives
There is an immediate data gap in proven technologies at the acceptable TRL for the safe destruction/disposal of existing AFFF inventories and concentrated rinses associated with AFFF swap-out. Given the high levels of PFAS in AFFF, destruction is a kinetically viable option if validated both technically and from a regulatory perspective. However, there is uncertainty over fate of PFAS compounds and intermediates in incineration and destruction processes. Therefore, there is a requirement for destructive alternatives to be validated by comprehensive tracking and mass balance of the fate of fluorine containing compounds to establish ultimate destruction efficiency. This presentation will provide an overview and a summary of current deployable PFAS treatment technologies with the potential TRL to provide data necessary to make technoeconomic decisions.
Approach/Activities
Conventional media (GAC, IX) are proven for dilute streams, but spent media and secondary waste streams require further management. Incineration has had a temporary moratorium placed on its use, enhancing the urgency of deploying alternative destruction technologies which break carbon fluorine bonds. When attempting to close the F mass, reduced PFAS concentrations, reduced total organic fluoride concentrations, and fluoride generation must all be accounted for. Suitable technologies at or near commercialization identified for treatment of AFFF concentrate/rinsate include hydrothermal alkaline hydrolysis (HALT), super critical water oxidation (SCWO), sonolysis, and reductive defluorination through UV-activated catalysts. However, data gaps and scalability concerns have yet to be addressed at the pilot scale.
Results/Lessons Learned
Due to the scale and scope of AFFF inventory, the development of cost evaluations to aid with cost estimates for the purposes of budgeting and developing contracts is a secondary goal to be met in this effort. This will provide a site manager with a list of validated technologies and associated cost estimates to facilitate contracting for PFAS destruction. Collection of feasibility and cost analysis will be holistic accounting for mobilization/ demobilization, energy, and operational requirements. This will provide stakeholders with the identification and selection of transitioning treatment technologies for consideration at sites.