Siphon-type air diffusion device, membrane bioreactor, and water treatment method

Abstract

A siphon-type air diffusion device for intermittently performing aeration, comprising: at least two siphon-type air diffusion pipes; and an air supply member that supplies air to the siphon-type air diffusion pipes, wherein the siphon-type air diffusion pipe includes a siphon chamber which includes a first siphon chamber and a second siphon chamber on the downstream side of the first siphon chamber, a communication portion which communicates the first siphon chamber and the second siphon chamber with each other, an air diffusion hole which is provided on the downstream side of the siphon chamber, a path which extends from the siphon chamber to the air diffusion hole, and a treatment water inlet which is provided on the upstream side of the siphon chamber, wherein the air supply member includes a distribution pipe which extends in an arrangement direction of the siphon-type air diffusion pipe, and an introduction portion which is branched from the distribution pipe and includes at least one air supply port supplying air to the siphon-type air diffusion pipe, wherein the distribution pipe is provided above the air supply port, and wherein in the air supply port of the introduction portion, the air supply port located at the uppermost position in the vertical direction is provided below a lower end of a partition wall dividing the siphon chamber and the path.