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Germany, Austria, Switzerland


Passavant® Fine Bubble Aeration Roeflex & Bioflex

Economically aeration of activated sludge tanks in biological wastewater treatment plants – whilst ensuring maximum oxygen transfer efficiency and a high level of process flexibility.

Unique Features

  • Successful long-term use in innumerable installations worldwide
  • Simple installation and low level of investment
  • High oxygen transfer – confirmed in numerous tests at accredited institutes
  • Optimum adjustment to tank form and operation depth
  • Best possible design - considering diffuser density, air flow and oxygen transfer - due to many years of experience


With the Passavant® Fine Bubble Aeration Aqseptence Group offers high quality diffuser which are employed in wastewater treatment plants throughout the world and have been continuously improved and developed by our company for more than 25 years.
When air is supplied, fine slits are opened in the elastic membrane and fine air bubbles are released into the water. When the air supply is swiched off, the slots close completely. The hydrostatic head presses the membrane firmly onto the support pipe, thereby the air inlet opening is sealed. This double sealing procedure prevents any liquid entry into system. In contrast to rigid porous diffusers e.g. ceramic, intermittent operation is possible and a high level of operational reliability and flexibility ensured.

In order to supply the appropriate diffuser for every treatment process, AS provides a variety of elastomer membranes which are created for the individual type of wastewater.