METHOD FOR TREATING ORGANIC WASTE

PROBLEM TO BE SOLVED: To provide an organic waste treating method in which an excess of sludge can be prevented from being generated by restraining activated sludge from propagating, drawing-out and retreating of sludge are unnecessary and organic waste can be treated with extremely high efficiency. SOLUTION: This organic waste treating method in which sludge is not withdrawn to the outside is carried out by adding the organic waste from a raw water tank 4 to activated sludge water in an aeration tank 12 so that the concentration of propagating nitrifying bacteria is not lowered, adding a pH adjusting agent from a pH adjusting agent tank 10 to the activated sludge water in the tank 12 so that the pH of the activated sludge water in the tank 12 is kept to be >=5, supplying oxygen of the amount equal to or more than the oxygen requirement to biodegradation of organic carbon in the activated sludge water, endogenous respiration of a microbe, nitrification of ammonia nitrogen and auto-oxidation of the microbe to the activated sludge water from a Roots blower 20 through an air diffusing pipe 18 and discharging the activated sludge water to the outside of the tank 12 so that the concentration of propagating nitrifying bacteria is not lowered.