Salt separation and destruction of PFAS utilizing reverse osmosis and salt separation
Per- and polyfluoroalkyl substances (PFAS) are destroyed by oxidation in supercritical conditions. PFAS in water is concentrated in a reverse osmosis step and salt from the resulting solution is removed in supercritical conditions prior to destruction of PFAS in supercritical conditions.
1. A method of treating the effluent from a method of destroying PFAS in a SCWO reactor, comprising:
passing an oxidant, PFAS, and water through a SCWO reactor to produce an effluent comprising aqueous HF, and treating the effluent by:
passing at least a portion of the effluent comprising aqueous HF into a mixing pipe where, the effluent is mixed with cooling water that optionally contains hydroxy salts;
wherein the effluent comprises a vapor stream comprising carbon dioxide and, optionally, oxygen gas and separating the vapor stream from a liquid stream.
2. The method of claim 1 , comprising:
passing at least a portion of the effluent through activated carbon.
3. The method of claim 1 , comprising:
filtering or centrifuging the effluent to remove precipitates.
4. The method of claim 1 , comprising:
treating the effluent by reverse osmosis.
5. The method of claim 1 wherein the method is conducted in a trailer.
6. The method of claim 1 wherein the effluent comprises a vapor stream comprising carbon dioxide and separating the vapor stream from a liquid stream.
7. The method of claim 6 wherein the vapor stream comprises carbon dioxide and oxygen gas.
8. The method of claim 1 wherein the cooling water contains hydroxy salts.
9. The method of claim 1 , comprising:
passing at least a portion of the effluent through an ion exchange resin.
10. The method of claim 1 wherein the effluent is evaporated into air.
11. A method of treating the effluent from a method of destroying PFAS in a SCWO reactor, comprising:
passing an oxidant, PFAS, and water through a SCWO reactor to produce an effluent,
wherein the effluent comprises a vapor stream comprising carbon dioxide and, optionally, oxygen gas and separating the vapor stream from a liquid stream; and
treating the effluent by removing solids from the effluent by spray drying.
12. A method of treating the effluent from a method of destroying PFAS in a SCWO reactor, comprising:
passing an oxidant, PFAS, and water through a SCWO reactor to produce an effluent,
wherein the effluent comprises a vapor stream comprising carbon dioxide and, optionally, oxygen gas and separating the vapor stream from a liquid stream; and
treating the effluent by spraying the effluent into a stream of hot air.
13. The method of claim 1 wherein water is evaporated from the effluent and solids are collected in a cyclone.
14. The method of claim 11 further comprising:
treating the effluent by one or more of the following:
passing at least a portion of the effluent through activated carbon or ion exchange resin;
passing at least a portion of the effluent into a mixing pipe where, optionally, the effluent is mixed with cooling water that optionally contains hydroxy salts;
treatment by reverse osmosis; and
filtering or centrifuging the effluent to remove precipitates.
15. The method of claim 12 further comprising:
treating the effluent by one or more of the following:
passing at least a portion of the effluent through activated carbon or ion exchange resin;
passing at least a portion of the effluent into a mixing pipe where, optionally, the effluent is mixed with cooling water that optionally contains hydroxy salts;
treatment by reverse osmosis; and
filtering or centrifuging the effluent to remove precipitates.
16. The method of claim 12 wherein the method is conducted in a trailer.