abstract |
Air polluted with potentially harmful chemical and biological matter is purified and pollutants degraded to less hazardous substances by a combined chemical and electrochemical process. Scrubber liquid-electrolyte circulated between scrubber and electrolyzer zones containing an electrochemically renewable degradant complexes or oxidizes the pollutants with the aid of an electrochemical cell in the electrolyzer zone which also reactivates the degradant in the scrubber liquid for recycling. Adsorption of insoluble organics is enhanced by stable surfactant additives to the scrubber liquid-electrolyte. Surprisingly, the electrochemical cell performs efficiently without separators or membranes when the non-working cathodes comprise Magneli phase substoichiometric titanium oxides which preferentially generate hydrogen instead of reducing redox couples to their inactive lower valence state. |