SUBSIDIARY FORMATION OF TRIHALOMETHANES B Y OXIDATION DECOMPOSITION USING SODIUM-HYPOCHLORITE OF LIQUID WASTE CONTAINING CYANIDE

Under the conditions of the oxidation decomposition reaction using sod ium hypochlorite of liquid waste containing cyanide, methyl ketones an d certain other compounds with bromide often afforded the reaction pro ducts, such as trichloromethane, bromodichloromethane, dibromochlorome thane and tribromomethane (referred to as ''trihalomethanes''). Trihal omethanes are regulated as environmental pollutants. In order to contr ol the formation of trihalomethanes, therefore, the formation conditio ns were examined. Using acetone, one of the trihalomethane precursors, the experimental results indicated that most of trihalomethanes were given by the first step reaction of the cyanide decomposition, and tha t large amounts of tribromomethane were produced on approximately pH 1 2. However, some of the formation conditions for trihalomethanes were different from those for the cyanide decomposition. It might mean that the formation reaction could be suppressed by the accurate control of the cyanide decomposition.