(402a) Development of Solubility Kinetics for Removal of PFAS from Granular Activated Carbon with Supercritical Carbon Dioxide
AIChE Annual Meeting
2024
2024 AIChE Annual Meeting
Environmental Division
Emerging Treatment Technologies and Characterization for PFAS Contamination II
Tuesday, October 29, 2024 - 3:30pm to 3:51pm
PFAS (per- and polyfluoroalkyl substances) compounds have contaminated many different matrices. Remediation of aquifers and other water sources have been one of the main focuses for research. Another major affected matrix exists in the solid form, such as solid waste, for example landfills and soil. These sources of contamination are both of major concerns because of the potential for PFAS compounds to leech into the undesirable areas due to the their resilient nature. Supercritical water oxidation (SWO) is a well-studied method for destruction of PFAS compounds. However, SWO of PFAS requires high temperatures and high pressures, and it is hazardous during operation because of the corrosive nature of SWO. Additionally, SWO may not selectively destroy PFAS when utilized in a crude feedstock, such as soil or hazardous waste.
A fluid is described as supercritical when the fluid is raised to a temperature and pressure that are above its critical temperature and pressure. When a fluid is supercritical, the fluid begins to have the diffusivity of a gas and the density of a liquid. Carbon dioxide is an abundant, low cost, and non-toxic fluid that has been used in supercritical fluid extraction (SFE) for decades. Carbon dioxide has a critical temperature of 31 degrees Celsius and a critical pressure of 74 bar. SFE with carbon dioxide has been shown to be effective in extracting nonpolar solids, and many PFAS compounds fit this profile.
SFE with carbon dioxide has been shown to be capable of removing a variety of PFAS compounds from various matrices. This extraction allows for a "concentration" of solid waste as well as the remediation of the solid matrices that have been contaminated.
In this work, we experimentally develop solubility parameters for PFAS compounds in supercritical carbon dioxide at varying temperatures and pressures. These parameters are used to develop a theoretical model that can predict and screen for efficacy of SFE in removing PFAS from affecting matrices.
A fluid is described as supercritical when the fluid is raised to a temperature and pressure that are above its critical temperature and pressure. When a fluid is supercritical, the fluid begins to have the diffusivity of a gas and the density of a liquid. Carbon dioxide is an abundant, low cost, and non-toxic fluid that has been used in supercritical fluid extraction (SFE) for decades. Carbon dioxide has a critical temperature of 31 degrees Celsius and a critical pressure of 74 bar. SFE with carbon dioxide has been shown to be effective in extracting nonpolar solids, and many PFAS compounds fit this profile.
SFE with carbon dioxide has been shown to be capable of removing a variety of PFAS compounds from various matrices. This extraction allows for a "concentration" of solid waste as well as the remediation of the solid matrices that have been contaminated.
In this work, we experimentally develop solubility parameters for PFAS compounds in supercritical carbon dioxide at varying temperatures and pressures. These parameters are used to develop a theoretical model that can predict and screen for efficacy of SFE in removing PFAS from affecting matrices.