Soil and water remediation method and apparatus for treatment of recalcitrant halogenated substances
Disclosed are methods, apparatuses and systems for the remediation of contaminated soils, groundwater, water, and/or waste using a combination of reagents. The disclosed methods may be used to treat various recalcitrant halogenated substances, such as perfluoroalkyls and polyfluoroalkyls. Particular combinations of reagents that may be used in the disclosed methods include but are not limited to: (1) persulfate, oxygen and ozone; (2) persulfate, salt, oxygen and ozone; (3) persulfate, phosphate, and/or oxygen; (4) persulfate, phosphate, oxygen and ozone; (5) persulfate, phosphate, salt and oxygen (6) persulfate, phosphate, salt, oxygen and ozone; (7) oxygen and salt; and (8) air and salt. The disclosed methods may enhance destruction of organic contaminants in the liquid phase and may also control the rate of aerosol or foam formation relative to the rate of chemical oxidation and/or reduction/transfer.
1. A method of removing poly and/or per fluorinated alkyl hydrocarbons from water, the method comprising:
passing gas bubbles through an aqueous phase contaminated with a contaminant comprising polyfluorinated alkyl hydrocarbons and/or perfluorinated alkyl hydrocarbons;
transferring contaminant from the aqueous phase to a foam; and
destroying contaminant in the foam by removing one or more fluorine atoms from an alkyl backbone of the polyfluorinated alkyl hydrocarbons and/or pefluorinated alkyl hydrocarbons via oxidation.
2. The method of claim 1 , wherein the gas bubbles comprise oxygen, ozone, nitrogen, or air.
3. The method of claim 1 comprising separating the foam from the aqueous phase.
4. The method of claim 1 comprising immobilizing the contaminant from the foam.
5. The method of claim 1 wherein destroying contaminant in the foam via oxidation comprises adding at least one of persulfate, ozone, hydrogen peroxide, oxygen and salt.
6. The method of claim 5 comprising destroying contaminant in the aqueous phase by introducing at least one of an activator, a catalyst, a complexing agent, a surfactant, an ionic species, and a co-solvent to the aqueous phase.
7. The method of claim 1 wherein destroying contaminant in the foam via oxidation comprises adding at least one of persulfate, ozone, hydrogen peroxide, oxygen and salt to the foam.
8. The method of claim 7 wherein destroying the contaminant in the foam includes treating the foam with persulfate or ozone.
9. The method of claim 1 further comprising removing the contaminant from the foam by using at least one of solid phase extraction, liquid-liquid extraction, filtration, distillation or adsorption.
10. The method of claim 1 comprising adding an oligosaccharide to the water.
11. The method of claim 10 wherein the oligosaccharide comprises cyclodextrin.
12. The method of claim 1 comprising introducing at least one of an activator, a catalyst, a complexing agent, a surfactant, an ionic species, and a co-solvent to the aqueous phase.
13. The method of claim 1 further comprising removing the contaminant from the foam by filtering through granular activated carbon.
14. The method of claim 1 , wherein a pH of the aqueous phase is greater than 5.0.
15. The method of claim 1 , wherein a pH of the aqueous phase is greater than 8.0.
16. The method of claim 1 comprising concentrating the contaminant.
17. The method of claim 1 wherein the method is performed in-situ.
18. The method of claim 17 wherein the method is performed in ground water, a well, a trench, a smear zone or an unsaturated zone.
19. The method of claim 1 wherein the method is performed ex-situ.
20. The method of claim 1 wherein the water is in contact with a soil contaminated with the contaminant.
21. The method of claim 1 comprising destroying contaminant using a combined oxidation/reduction reaction.