Ultrasonic High Voltage at High Frequency applied by Carbon electrodes at ambient atmospheric pressures and temperatures breaks the Fluorine – Carbon bonds in waterborne PFAS and subsequently reacts the generated toxic by-product Hydrogen Fluoride with Calcium Hydroxide making harmless Calcium Fluoride and Calcium Carbonate filtrate.

A Municipal Scale system provides 3,000 GPH or more of PFAS free water suitable for commercial and civil applications.

Waterborne PFAS particles up to 30 microns in size come into contact with the cylindrical graphite cathode ( in Blue ) convoluted surfaces shown below. This electrode geometry provides maximum cathodic reactive surface area with ribs machined to generate turbulent vortices as water flows over said surfaces. This ensures contact with the reactive cathodic surfaces with the PFAS particles as they pass through the reactor. Three separate high voltage multipliers working in phase provide uniform power density to the reactive carbon surfaces to generate Hydrogen Fluoride from the PFAS making Hydro-fluoric acid.

Our proof of physics is shown here comprises of a square glass water vessel fitted with a pH meter and a Hydrogen Fluoride gas sensor. The water is plain tap water with no additives whatsoever. The reactivity showing here was obtained around 12 kV. at 3.7 kHz High Voltage and High Frequency.

PTFE (Teflon) tape is the target source of PFAS which was rolled around a carbon electrode. 12 kV at 3.7 kHz. of AC is applied between two carbon (graphite) electrodes. Controls are AC voltage, AC frequency applied to the carbon electrodes.

Outgassing at the electrode surface comprises OH hydroxyls, CO2, and Fluorine that is spalled and exfoliated out of the Teflon tape at the points of contact to the carbon electrode surface. The Fluorine immediately combines with a free hydrogen ion to form Hydrofluoric acid.

The HF-10 Hydrogen Fluoride sensor by Sensor Tec Amphenol is calibrated to 4 mV @ 1 ppm HF gas sensitivity.

Sample gas is periodically extracted at the water surface with a miniature air fan in a plenum housing where the sensor face is embedded and is exposed to the gas stream extracted from within the glass jar. The HF gas goes into solution quickly and most does not make it to the water surface.

HF Sensor Schematic

An initial 400 mV signal excursion shows a concentration of extracted HF gas to be 100 ppm peak which decreases quickly as the air at the water surface is evacuated over time by the fan. The data points in the graph are 5 seconds apart.

This gas could not have been produced from any other source than from the yellow Teflon tape ( PFAS ) wrapped around the carbon electrode.

Clearly, the gas sample contains Hydrogen Fluoride indicating breakage of the fluorine / carbon bonds in the PFAS molecules.

Neutralizing the Hydrofluoric acid with Calcium Hydroxide thus;

Hydrofluoric acid reacts immediately with the Calcium Hydroxide “Milk of Lime” and nucleates Calcium Fluoride crystalline solids with Calcium Carbonate out of the water. Calcium Fluoride crystalline solids are filtered out by a subsequent permeable carbon filter sock downstream.

Fluorite and Calcium Carbonate are harmless non-toxic substances whose mass concentrations are commensurate with the in-flows of the untreated water (ppm)

The calcium hydroxide sits at the very bottom of the drum and is expected to last for years infusing “Milk of Lime” Calcium Hydroxide into the water that is dosed with Hydrogen Fluoride from the previous electrolytic stage.

The crystalline mineralized solids are captured by the carbon filter screen sock before egress as treated potable drinking water free of PFAS.