Use of electrochemical oxidation for treatment of per-and polyfluoroalkyl substances (PFAS) in waste generated from sorbent and resin regeneration processes

A water treatment system for destroying at least one of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in a liquid stream by electro-oxidation, the water treatment system comprising:

• a filter or sorbent for concentrating the at least one of perfluoroalkyl and polyfluoroalkyl substances from the liquid stream;
• a pump for pumping regenerant from a supply tank to wash the filter or sorbent to generate a spent regenerant containing the concentrated perfluoroalkyl and polyfluoroalkyl substances;
• a tank for generating still bottoms from the spent regenerant;
• and
• a continuous flow through electro-oxidative (EO) reactor, comprising an electrolytic cell with an anode electrode and a cathode electrode, wherein the anode electrode and the cathode electrode are configured to contact at least the still bottoms while a current flows between the electrodes, thereby destroying at least some of the at least one of perfluoroalkyl and polyfluoroalkyl substances by electro-oxidation to form a reclaimed regenerant,
• wherein at least one of the anode electrode and the cathode electrode comprises titanium suboxide;
• and
• wherein the reclaimed regenerant is moved from the electrolytic cell to the supply tank to be reused to wash the filter or sorbent.

A process for destroying at least one of perfluoroalkyl and polyfluoroalkyl substances in a liquid stream by electro-oxidation, the process comprising:

• concentrating the at least one of the perfluoroalkyl and polyfluoroalkyl substances from the liquid stream using a filter or sorbent;
• washing the filter or sorbent with a regenerant to generate a spent regenerant containing the concentrated perfluoroalkyl and polyfluoroalkyl substances;
• generating still bottoms from the spent regenerant;
• continuously flowing the still bottoms through an electro-oxidative (EO) reactor in a continuous flow through mode;
• contacting the at least the still bottoms with the EO reactor, comprising an electrolytic cell having an anode electrode and a cathode electrode, while a current flows between the electrodes, the contacting destroying at least some of the at least one of the perfluoroalkyl and polyfluoroalkyl substances by electro-oxidation to form a reclaimed regenerant, wherein at least one of the anode electrode and the cathode electrode comprises a titanium suboxide;
• and
• reusing the reclaimed regenerant to wash the filter or sorbent.