The performance of two corona reactors, falling film type and rotating disk type, were evaluated for their efficiency in oxidizing a ferrous sulfate solution in the presence of moist air. The falling film type was found to be superior and additional studies were conducted to characterize those process variables which affected reactor performance. From the data, a linear least squares regression equation was derived, giving an approximation of the underlying relationships. The falling film type was also evaluated for its ability to oxidize aqueous solutions of benzoic acid, alkyl benzene sulfonate, filtered secondary effluents, and effluents from a carbon adsorption column. The easily oxidized ferrous ion reacted with corona activated species which did not strongly attack the organic materials.