Background
Adsorption is the main water treatment technology that is commercially used to remove per- and polyfluoroalkyl substances (PFAS) from water. These substances are in thousands of everyday products due to their high stability and chemical resistance, but are non-biodegradable and can pose risks to human health.
Current adsorption techniques for PFAS removal exhibit high performance, but result in the production of PFAS-laden spent carbon as an end product. Disposal of spent carbon results in the undesired leaching of PFAS back into the environment. Carbon regeneration techniques have the potential to circumvent this issue, but are not widely commercially used yet.
Invention Description
Researchers at Arizona State University have developed a novel electrified regenerative method to enact fast reuse of spent carbon and the recovery of an enriched effluent for enhanced destructive method by other techniques, including electrochemical oxidation, advanced oxidation, or biological treatment. This method minimizes waste PFAS-laden absorbents in landfills and decreases the amount of carbon emissions associated with incineration of these sorbents. In initial tests, electro-regeneration of saturated F400 carbon reinstated up to 60% of initial capacity.
Potential Applications
- Water treatment plants
- Point-of-use PFAS removal systems
Benefits and Advantages
- Avoids undesired leaching of PFAS
- Avoids formation of CFC during pyrolysis
- Minimizes capital cost expenditures (enables sorbent reuse)