Introduction

This patent protects an innovative electrode configuration for an atmospheric plasma discharge reactor for water treatment, especially effective in the degradation of persistent organic pollutants such as PFAS.

Technical features

Advanced Oxidation Processes (AOPs) are often used to remove recalcitrant contaminants from polluted water, but require high energy and the addition of chemicals and/or additives. The application of atmospheric plasma to the treatment of contaminated water is a promising alternative and eco-friendly technology since the reactive species responsible for the degradation of organic pollutants are generated in situ directly from the gas above the solution and the water itself following the application of an electrical discharge. This technology has proven especially effective for the degradation of recalcitrant organic contaminants, such as per- and polyfluoroalkyl substances (PFAS). This patented configuration of the electrodes is capable of producing a more efficient plasma  in pollutant degradation thanks to the higher ratio between the plasma surface and the volume of the treated water with respect to the previously developed plasma reactors. The technology has been validated on a laboratory scale prototype (TRL 4) with PFOA concentrations between 40 ppb and 40 ppm.

Possible Applications

Treatment of water contaminated using:

• Recalcitrant organic compounds, in particular PFAS;
• Other pollutants and surfactants.

Advantages

• Effective degradation of recalcitrant organic substances like PFAS;
• Green technology: no use of chemicals is required;
• Operates at room temperature and atmospheric pressure;
• Higher plasma surface to volume ratio than offered by related systems;
• More energy-efficient treatment compared to related systems;
• Easy to install and maintain;
• Very short switch on/off times.