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Germany, Austria, Switzerland


Surface Aerator

Reliable and efficient oxygen enrichment with effective matter distribution and activated sludge circulation - as a basis for the optimal activity of microorganisms and thus a particularly good extraction of pollutants in biological wastewater treatment systems.


Oxygen transfer occurs during the operation of the Mammutrotor® by means of an intensive turbulence of the phase boundary between the air and the wastewater/activated sludge mixture, directly at the aeration rotor. The flow energy which is simultaneously introduced ensures the requisite blending of the activated sludge, wastewater and oxygen. This ensures sedimentation-free operation in tanks with a depth of up to 3.5 m. In deeper tanks of up to 8 m, the mixing process is supported by additional agitators which allow an intermittent mode of operation, in addition to the continuous mode. The oxygen enrichment efficiency and the cost effectiveness of the system are further enhanced by the optional installation of guide baffles mounted transversely to the outflow of the aeration rotors.


  • Particularly robust operation and long service life
  • Constant oxygen input throughout the entire service life
  • Trouble-free maintenance and low maintenance requirements - all relevant parts above the surface of the water
  • Flexible fields of application with regard to possible control strategies and treatment goals
  • No negative influence on oxygen input through wastewater content - α-factor is 1

Further informations

With the Passavant® Surface Aerator Mammutrotor® Passavant-Geiger offers you a universal solution which has been especially developed for aeration, circulation and stir mixing processes. More than 8,500 installations with a total length of approximately 52 km have meanwhile been deployed worldwide and the Mammutrotor® has become the byword for economic and reliable surface aeration.

Design Features

The heart of the system is the actual aeration rotor, a central shaft with clamped star mountings made of glass-fiber reinforced plastic. Their slightly spiralled arrangement ensures low-noise, shock-free operation. The drive unit and the end bearing are equally important for the provision of stable low-maintenance operations over the course of many years. The system is, therefore, driven by a straight bevel gear with a three phase motor. The gear unit – just as the end bearing – have been tailor-made by Passavant® for this particularly challenging field of application and successfully employed in conjunction with the Mammutrotor® for many years.