For this project, a prototype mobile indirect thermal desorption coupled with thermal oxidation (ITD/TO) system will be demonstrated that requires minimal on-site infrastructure development and is capable of quick setup and operation to perform onsite destruction of per- and polyfluoroalkyl substances (PFAS) in impacted soil, sediment, and/or biosolids (hereafter, collectively referred to as solids) ranging in concentrations from low parts per billion to high parts per million. This demonstration will answer the following technical questions with respect to the prototype ITD/TO system:

1. Is the on-site mobile system capable of achieving a destruction and removal efficiency of 99.99% for the suite of PFAS present in sediment during ITD/TO treatment?
2. Can a fluorine mass balance be closed with this mobile treatment system to within +/- 30% to confirm complete destruction of PFAS?

The prototype system includes a high-efficiency particulate filter, a thermal oxidizer, an adiabatic gas quencher, and an acid gas scrubber. Key operational parameters include a throughput capacity determined by the batch dryer's size, with an estimated volumetric capacity of up to 93 cubic feet (8,350 pounds) of solid media per batch. The treatment temperature ranges from 450°C to 650°C. The thermal oxidizer's maximum fuel firing rate is specified at 3.0 metric million British thermal units per hour. These detailed parameters underscore the operational efficiency and performance of the ITD/TO system for relatively small volumes of PFAS-impacted soil, positioning it as an advanced, adaptable, and easily deployable technology for treatment of PFAS investigation-derived waste (IDW).

The prototype system is highly mobile, implemented on-site, and has a small spatial footprint. It provides the opportunity for beneficial reuse of treated media and, depending on the volume of soil IDW, can be deployed at lower cost compared to conventional options. ITD/TO has demonstrated efficacy as a treatment technology for traditional co-occurring chemicals with PFAS. Further development of this PFAS destruction technology will directly impact the Department of Defense's ability to maintain operational readiness through the development of affordable, deployable solutions to protect critical installations and personnel, bolstering national defense capabilities. (Anticipated Project Completion - 2026)