A bubbly approach to PFAS-free water
S. Himmelstein | November 05, 2024
The health hazards posed by “forever chemicals” – per- and poly-fluoroalkyl substances (PFAS) -- pose a challenge for the water supply and treatment sector. The cost- and time-intensive processes conventionally deployed to address these toxic pollutants in potable water may soon be replaced with an efficient hydrodynamic cavitation reactor developed by an international team of researchers.
The reactor uses fast-moving liquid in restricted channels to generate and collapse small bubbles via changes in pressure. The scalable process described in Chemical Engineering Journal degrades and eliminates PFAS through this cavitation scheme.
When tested at a wastewater treatment facility in Sweden, the reactor achieved a 36% degradation rate of 11 common PFAS variants in just 30 minutes without the need for chemical additives.
“Our next step is scaling up our reactor to treat larger volumes of wastewater containing PFAS. We are aiming to treat wastewater containing PFAS volumes up to 20 liters. The reactor for this has already been built. After that, our target is to treat volumes up to 200 liters in a wastewater treatment plant in Sweden,” noted the researchers.
The hydrodynamic cavitation reactor was developed and tested by scientists from Sabanci University (Turkey), IVL Swedish Environmental Research Institute, Ankara University (Turkey), Oxford Brookes University (U.K.), University of Oxford (U.K.) and KTH Royal Institute of Technology (Sweden).
Perhaps an ultrasonic generator would be more efficient than the forced high velocity water?Cavitation can be achieved many ways,and when the bubbles collapse, it generates extremely high temperatures approaching the temperature of the surface of the sun.I can certainly understand how this would break down chemicals.
I can imagine an array of ultrasonic generators on the bottom of a clarifier basin,or an aerator basin.
I am sure this method has been considered by the experts in the field.
I know that a foaming detergent will weaken or destroy the cavitation action in an ultrasonic bath by preventing bubble collapse,so a non foaming detergent must be used to prevent bubble formation.
Perhaps this is the reason for their method of cavitation vs ultrasonic--the liquid is not conducive to ultrasonic pulses.
I hope eventually their method can be developed for multi-MGD treatment plants.
How about a small under sink or an in-line model for home use?
A simple mod of a commercial ultrasonic bath would work.I think I will work on that.
---Jus' thinkin'
