Processes commonly applied to remove per- and polyfluoroalkyl substances from water can effectively absorb these contaminants but still require destruction of the captured “forever chemicals.” Other remediation techniques can be cost- and energy-intensive, prompting researchers to devise a more energy efficient and environmentally friendly route to PFAS removal.

Researchers from the University of New South Wales (Australia) and Stockholm University (Sweden) tested different nano zero-valent metal (nZVM)-based catalysts, widely used to treat chlorinated compounds in groundwater, as PFAS defluorination agents. The nZVM catalysts were combined with porphyrin, a vitamin B12 analogue as a reductant, and evaluated for their power to catalytically degrade and defluorinate PFAS compounds.

Soluble cobalt porphyrin complexes proved more effective relative to insoluble Vitamin B12-only catalysts. About 75% of the fluoride was released from branched PFAS contaminants within about five hours, significantly reducing the amount of PFAS within the solution. The B12 based catalyst system achieved less than 8% defluorination within that time duration.

The catalysts described in the journal Water Research also proved to be reusable for many treatment cycles, and the researchers plan to next demonstrate the system on a pilot scale.