| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide technology for reducing the possibility that a discharge of gas becomes uneven. <P>SOLUTION: An air diffusion device includes a pipe part formed with a gas flow passage thereinside, and extending from a first position to a second position not overlapping the first position when viewing a state that the pipe part is incorporated in a wastewater treatment apparatus downward from above. The pipe part is a portion forming at least one of the lower face and the upper face when the pipe part is incorporated in the wastewater treatment apparatus, and has a flat surface portion whose outer surface is formed in a flat surface state and a plurality of gas-discharging discharge holes formed in the flat surface portion. <P>COPYRIGHT: (C)2013,JPO&INPIT |
