Patent ID: 10723646

Abstract:
An organic wastewater treatment method that includes a raw sludge removal step, a raw sludge concentration step, a biological treatment step, an excess sludge separation step, an excess sludge concentration step, a sludge mixing step, and a methane fermentation treatment step. The treatment method further includes a sterilization step for heating and sterilizing the concentrated excess sludge upstream of the sludge mixing step. At least one among: (1) the temperature to which the concentrated excess sludge is heated during sterilization, (2) the concentration of concentrated raw sludge and/or the concentration of the concentrated excess sludge, and (3) the mixture ratio between the concentrated raw sludge and the concentrated excess sludge is adjusted according to the fluctuation in the amount of raw sludge generated and the amount of the excess sludge generated, and the temperature of the mixed sludge is controlled to a temperature suited for methane fermentation.