PFAS-Contaminated Soil and Water
PFAS are a persistent recalcitrant family of compounds, characterized by long, fluorinated carbon chains. Remediation of PFAS-contaminated soil and water has had limited success due to the chemical stability of PFAS, although thermal treatment options are currently being explored as the best option for achieving substantial destruction of PFAS. Due to the high thermal stability of PFAS, however, temperatures greater than 700°C are required to destroy PFAS and temperatures above 1000°C are necessary to minimize production of short-chained volatile organic fluorines (VOFs) and fluorinated dioxins and furans (PFDD/F).
Self-sustained smoldering is a low-cost/energy thermal technique for the treatment of contaminated soils. Temperatures in excess of 700°C or even 1000°C are possible, depending on the conditions of the system and the fuel being combusted.
Savron is currently conducting proof-of-concept laboratory studies to explore the application of smoldering combustion to treat PFAS-impacted soils and media. Results to data demonstrate that:
- Granular activated carbon (GAC) can be used to support smoldering combustion to achieve temperatures that destroy PFAS when added to soils at ~40 to 60 g/kg.
- PFAS absorbed to GAC or soils can be treated via smoldering combustion resulting in non-detectable levels in soils, sand and ash.
Hydrogen fluoride (HF) is generated suggesting that complete decomposition of PFAS via smoldering combustion is possible.
Laboratory work continues and opportunities for a field demonstration of the technology are being evaluated.