1. Air diffuser and membrane bio-reactor

2. An air diffuser includes a porous fabric panel having areas of different flow coefficients.

3. The present invention relates to: an air diffuser including an aeration tube in which at least two air hole groups including two or more air holes are formed; and a membrane bio-reactor including the air diffuser.

4. A new swirling cold air diffuser has been researched after tests of aerodynamics, the velocity field, the temperature field and yawp.