Liquid waste treatment device and liquid waste treatment method

摘要

The purpose of the present invention is to keep the quality of water in a reaction vessel for a UASB treatment in a state in which the reaction activity of a microorganism becomes high. A liquid waste treatment device (1) comprises: a reaction vessel (10) in which water to be treated is supplied from the bottom part (100) of the reaction vessel (10) to allow the water to contact with a mass of microorganism and the water is then discharged from the upper part of the reaction vessel (10) as treated water; and a pH adjustment vessel (18) in which the pH value of a portion of the treated water which flows out of the reaction vessel (10) is adjusted. The pH adjustment vessel (18) is connected to the side surface of the reaction vessel (10) through a feed pipe (181b or 181c), the pH value of a portion of the treated water which is discharged from the reaction vessel (10) is adjusted to a pH value at which the reaction activity of the mass of the microorganism becomes high, the treated water of which the pH value has been adjusted is injected to a part which is a bed (19) in the reaction vessel (10) and is apart from an inlet (100) for the water to be treated along the direction of the flow of the water to be treated.