DETOXIFICATION OF SOUR CAUSTIC WASTES ON HETEROGENEOUS PHTHALOCYANINE CATALYST

The authors develop a method to utilize mercaptan-containing SCW by SCW detoxification. This process consists of the oxidation of sodium sulfide by atmospheric oxygen to the less harmful sodium thiosulfate and sulfate, and the oxidation of sodium mercaptides to organic disulfides that are insoluble in the SCW and are separated from the wast stream by settling in oil traps. This process was developed for the heterogeneous catalytic oxidative detoxification of SCW on the KS-1 catalyst. In the heterogeneous catalytic detoxification of SCW, there is no atmospheric pollution by any discharges of hydrogen sulfide or sulfur dioxide. The proposed method consumes little heat and does not consume any reagents such as carbon dioxide or sulfuric acid. Cost-effective advantages of the process is discussed.