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US 5,516,972 AGranted
Mediated electrochemical oxidation of organic wastes without electrode separators
AssigneeThe Regents of the University of California
InventorsJoseph C. Farmer, Francis T. Wang, Robert G. Hickman, Patricia R. Lewis
Life of this patent
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Abstract
An electrochemical cell/electrolyte/mediator combination for the efficient destruction of organic contaminants using metal salt mediators in a sulfuric acid electrolyte, wherein the electrodes and mediator are chosen such that hydrogen gas is produced at the cathode and no cell membrane is required.
Claims6
A process for the destruction of organic containing wastes in an undivided electrochemical cell, comprising the steps of:
- (1) placing an organic containing solution in an electrochemical cell, said cell including an anode and a cathode with no cell separator therebetween, an electrolyte comprising sulfuric acid and a cobalt salt mediator, wherein said mediator, said anode and said cathode are selected such that
- (a) the potential for deposition of a solid cobalt metal on said cathode is more cathodic than that required for H.sub.2 evolution,
- (b) a metal ion Co(II) of said mediator is oxidized at said anode at less anodic potentials than those required for O.sub.2 evolution, and
- (c) an oxidized form of said metal ion Co(III) is sufficiently oxidizing to convert organics dissolved in said electrolyte into CO.sub.2 ;
- (2) applying a potential across said anode and cathode so as to cause a reduced form of said mediator to become oxidized at said anode, and hydrogen gas to form at said cathode;
- (3) allowing said organic and solvent to react with said oxidized mediator to form carbon dioxide, water and a reduced form of said mediator;
- and
- (4) repeating steps (2) and (3) until a desired amount of organic has been destroyed.
5 more elements
A process for the destruction of organic containing wastes in an undivided electrochemical cell, comprising the steps of:
- (1) placing an organic containing solution in an electrochemical cell, said cell including a platinum anode and a platinum cathode with no cell separator therebetween, an electrolyte comprising sulfuric acid and a cobalt salt mediator, wherein said mediator is selected such that
- (a) the potential for deposition of solid cobalt metal on said cathode is more cathodic than that required for H.sub.2 evolution,
- (b) a metal ion Co(II) of said mediator is oxidized at said anode at less anodic potentials than those required for O.sub.2 evolution, and
- (c) an oxidized form of said metal ion Co(II) is sufficiently oxidizing to convert organics dissolved in said electrolyte into CO.sub.2 ;
- (2) applying a potential across said anode and cathode so as to cause a reduced form of said mediator to become oxidized at said anode, and hydrogen gas to form at said cathode;
- (3) allowing said organic and solvent to react with said oxidized mediator to form carbon dioxide, water and a reduced form of said mediator;
- and
- (4) repeating steps (2) and (3) until a desired amount of organic has been destroyed.
5 more elements
Dependencies are inferred from the claim text.