METHOD FOR TREATING SEWAGE

PROBLEM TO BE SOLVED: To provide a method for treating sewage which is capable of efficiently agitating the sewage in a oxgen-free state without destroying carriers to which denitrifying bacteria are immobilized and which are fed into an anaerobic tank. SOLUTION: This method for treating the sewage consists in executing the nitrification and denitrification of the sewage by successively admitting the sewage from an anaerobic tank 1 into which the carriers T1 immobilizing nitrifying bacteria are fed into an anaerobic tank 2 into which the carriers T2 immobilized with the denitrifying bacteria are fed, in which the agitation of the sewage in the anaerobic tank 2 is effected by an ejector effect of the water flow generated when the sewage subjected to an aerobic treatment by aeration agitation in the aerobic tank 1 is admitted into the anaerobic tank 2.