Please choose region and language


Germany, Austria, Switzerland


Passavant® Fine Bubble Aeration Roeflex & Bioflex

Proven worldwide: Economical aeration of activated sludge tanks in biological wastewater treatment plants – with maximum oxygen transfer efficiency and the highest degree of process engineering flexibility.

Unique Features

  • Easy installation and low investment
  • Proven worldwide in countless installations with long service life
  • High oxygen input – proven by numerous tests of renowned institutes
  • Optimal adaptation to tank shape and operation depth
  • Best possible design considering occupancy density, air flow and oxygen transfer – thanks to many years of experience


The Passavant® Fine Bubble aeration system with proven membrane diffuser is used in wastewater treatment plants worldwide and is constantly being further developed. Unlike rigid-porous diffusers, e.g. made of ceramics, intermittent operation is possible, thus ensuring high operational reliability and variability.

For air supply, tiny slits open in the elastic membrane so that fine air bubbles are released into the water. When the air supply is turned off, the slits close completely. At the same time, the hydrostatic head presses the membrane firmly onto the support pipe, thus sealing the air inlet opening. This double seal prevents liquid from entering the aeration system.

Diaphragms made of different elastomers are available to provide the right diffuser for any wastewater.