Rikke Bruun

The bubble fractionation process is a highly efficient separation technology for the removal of PFAS from water, using only air as the driving force. This method produces a PFAS-enriched concentrate, with concentrations of PFAS4 and PFAS22 increased by factors of 5,000 and 4,000, respectively, compared to the original water matrix.
Subsequent degradation of the PFAS in this concentrate using UV/VUV-ARP technology yielded promising results, achieving complete removal of PFAS4 and a 99.8% reduction of PFAS22 within a 27-hour treatment period. During the degradation process, fluoride ions (F⁻) were released, serving as a direct indicator of PFAS breakdown. A total defluorination of 90.4% was obtained, confirming that the majority of PFAS compounds were fully mineralized.
During UV/VUV-ARP treatment other degradation products than free F⁻ are formed. These are shorter-chain PFAS and partially defluorinated derivatives. These intermediates can be degraded through extended treatment duration resulting in an effluent which will comply with the EU limit values (EQS) for direct release to the water environment.

The results demonstrate that UV/VUV-ARP can effectively degrade PFAS not only in clean water but also in natural water matrices. This indicates that the method, operated at ambient temperatures and pressure, has the potential to be integrated into a complete treatment train for PFAS removal from water with subsequent on-site destruction of PFAS residues. This shows promising signs of replacing the very costly and energy-intensive conventional high-temperature incineration of PFAS waste.
Since the UV/VUV-ARP involve treatment of a concentrated PFAS stream generated through bubble fractionation, the volume of water to be treated is significantly reduced and the energy consumption can be kept below 1 kWh/m³. This makes the UV/VUV-ARP a highly sustainable and cost-effective technology for PFAS destruction.