Destruction of PFAS Via an Oxidation Process and Apparatus Suitable for Transportation to Contaminated Sites
Per-and polyfluoroalkyl substances (PFAS) are destroyed by oxidation in supercritical conditions. PFAS in water can be concentrated and prepared for destruction in a pretreatment phase. Following annihilation of the PFAS in supercritical conditions to levels below 5 parts per trillion (ppt), the water effluent can be used to recover heat, returned to sub-critical conditions, and then released back into the environment.
1 - 36 . (canceled)
37 . A method of destroying PFAS, comprising:
passing an aqueous PFAS mixture into a system comprising a SCWO reactor;
reacting the aqueous PFAS mixture under supercritical conditions under continuous operation in the SCWO reactor;
wherein the SCWO reactor comprises metallic walls; and
during the step of reacting, supplying an electron flood from an external source to the system.
38 . The method of claim 37 wherein the external source comprises a controllable electronic board.
39 . The method of claim 37 further comprising reacting the aqueous PFAS mixture in the presence of a eutectic mixture of alkali and/or alkaline earth salts.
40 . The method of claim 37 further comprising reacting the aqueous PFAS mixture with an aqueous oxidant and, subsequently, reacting with an alkali or alkaline earth compound or mixtures thereof.
41 . The method of claim 40 wherein the alkaline earth compound is calcium oxide.
42 . The method of claim 38 wherein the controllable electronic board supplies electrons to increase electron flow without increasing DC voltage.
43 . The method of claim 40 wherein the aqueous oxidant is hydrogen peroxide.
44 . A method of handling effluent from a process of destroying PFAS, comprising:
the effluent comprising the decomposition products of PFAS; and
filtering and/or centrifuging precipitates from the effluent; or
flashing and/or evaporating the effluent; or
spray drying the effluent; or
any combination of these.
45 . The method of claim 44 further comprising subjecting the effluent to reverse osmosis.
46 . The method of claim 44 further comprising passing the effluent through a heat exchanger, wherein heat from the effluent is transferred to an aqueous PFAS mixture entering a SCWO reactor or system.
47 . The method of claim 44 further comprising adding chelating agents to the effluent.
48 . The method of claim 44 further comprising passing the effluent through a sorbent.
49 . A method of destroying PFAS, comprising:
passing an aqueous PFAS mixture through a plurality of electrodes;
forming HF from the aqueous PFAS mixture;
and, subsequently, reacting the HF with an alkali or alkaline earth element.