Abstract: Acid water containing negative charge oxygen atoms and showing an acidity level higher than pH 5 is provided. Acid water of a pH level not lower than pH 5 is prepared by conveying negative charge oxygen atoms produced by heating a composite oxide enclosing active oxygen by themselves or by means of gas not reacting with water and contacting them with water.
Abstract: The invention provides a gaseous organic compound disposal system comprising an oxidizing portion which dispenses with heating means and operates at normal temperature, and on or in which an oxidizing catalyst containing 12CaO.7Al2O3 is carried or filled at a position in contact with a gas feed containing gaseous organic compounds.