Adsorption & destruction evidence
Is it correct that 99,9 % of the PFAS can be eliminated? YES
In the SCWO process, we are treating either saturated adsorbents or concentrated water streams. Our SCWO reactor has an operating pressure at 250 bar and the water is heated above 600C to ensure complete elimination of the PFAS compounds.
We are measuring multiple parameters to ensure that everything has been mineralized.
- Free fluoride and Sulphur: released from the degradation of PFAS (sulphur from sulphonic acids like PFOS and PFHxS).
- Drop in pH due to acid generation as we generate low concentrations of HF and H2SO4.
- Sum of PFAS (21) before and after the treatment.
- Organically bound fluoride
- Chemical oxygen demand
- Exhaust oxygen levels
Results from Swedish landfill: SÖRAB:
The Norwegian defense have been very active at Rygge Airport, where they have used activated carbon to capture PFAS, but the PFAS is still on the coal, where the capacity is low, especially for the short-chain PFASs. This means that activated carbon must be changed very often. An alternative to changing coal often is to “wash” the coal off and thus get a highly concentrated stream to be treated and then reuse the coal.
We have carried out experiments with recycling of the coal from Rygge together with DTU Environment and the Danish Technological Institute. In these experiments, we washed activated carbon from Rygge and sent the “washing water” through our SCWO plant.
Below is a table with DTU Environment’s data showing before and after concentrations when treating with SCWO.
Have PFAS been effectively removed from groundwater? YES
Removal from water phase is done by adsorbents. We are using specific ion exchange resins, designed to have a high adsorption capacity for PFAS.
Data from Korsør Brandskole:
Can extreme concentrations of PFAS be destroyed by SCWO? YES
AFFF firefighting foam contains very high amounts of PFAS. For the US EPA we have done destruction experiments, where we destroy original PFAS-containing firefighting foam, which contains 4 billion ng PFAS/l.