Abstract: A process for treating waste water of flue gas desulfurization comprising successively adjusting the pH of the waste water to 5 or less, bringing the waste water into contact with a column packed with fine particles of iron, flocculating the waste water, removing formed flocs from the waste water by solid-liquid separation, and optionally, bringing the remaining waste water into contact with a resin for COD adsorption, successively. Hazardous substances, such as oxidative substances, peroxosulfuric acid, iodic acid, heavy metals such as copper and lead, and non-metallic substances such as selenium compounds and fluorites, can be removed simultaneously and efficiently from the waste water of flue gas desulfurization containing these hazardous substances by using the process which is a simplified waste water disposal system.

Abstract: A method for decomposing volatile organic halogenated compounds in water containing such compounds and metal ions by removing the metal ions from the water and then contacting the deionized water with a reducing agent in the presence of a catalyst. The volatile organic halogenated compounds are efficiently decomposed with a small energy requirement and low cost to eliminate, thus, making the water safe.

Abstract: A method of treatment of a liquid or gaseous fluid to decompose volatile organic halogenated compounds therein comprises bringing the fluid containing volatile organic halogenated compounds in contact with a reducing agent in the presence of a metal catalyst and optionally thereafter treating the thus treated fluid with at least one of an adsorption treatment, a thermal decomposition and a biological decomposition treatment. The method efficiently decomposes the volatile organic halogenated compounds contained in a fluid, such as water or a gas, with a small expenditure of energy and at low cost and renders the fluid harmless to the environment.