METHOD OF PROCESSING POLLUTED WATER CONTAINING HARDLY BIODEGRADABLE ORGANIC SUBSTANCE

摘要

PROBLEM TO BE SOLVED: To provide a method of processing polluted water containing organic matter which is hardly biodegradable to improve the process efficiency by efficiently producing hydroxy radicals from ozone and hydrogen peroxide. SOLUTION: Polluted water 2 poured into an oxidizing tank 1 is aerated with ozone gas from an ozone supply device 11 by an aerating means 12. The water is circulated through a circulation pipe 16 of a circulating means 14 and the ozone concentration is detected by an ozone concentration meter 17. A pump is controlled by a controlling means 18 according to the detected ozone concentration to add hydrogen peroxide 5 by a hydrogen peroxide adding means 4 to the polluted water 2. Hydrogen peroxide 5 is added to keep the ozone concentration in the polluted water to >=0.1 mg/l and <=0.5 mg/l. The organic matter in the polluted water 2 is oxidized and decomposed by hydroxy radicals produced by supplying hydrogen peroxide 5 and ozone gas. The polluted water 2 is purified by active sludge in a biological processing tank in a succeeding step to decompose the remaining organic matter having a low mol.wt. The production efficiency of hydroxy radicals can be improved by the coexistence of hydrogen peroxide 5 and ozone.