Membrane wastewater treatment plants (MBR) deliver a water quality thousands of times better from a microbial point of view compared to conventional wastewater treatment plants – with a significantly smaller footprint for the overall plant.

improvement in water quality


wastewater treatment plant

= a biological wastewater treatment process in wastewater treatment plants consisting of:

  • Pre-treatment of the raw wastewater.
  • Biological stage in which microorganisms in the activated sludge are used to degrade wastewater components.

  • Secondary sedimentation (clarifier) for the separation of sludge and treated wastewater by sedimentation


membrane bioreactor

= combination of classical wastewater technology with membrane filters in so-called membrane bioreactors (MBR).

  • Membranes are submerged in the biological stage.
  • Membrane filters enable higher sludge concentrations in the activated sludge stage leading to smaller tank volumes.

  • The separation of sludge and treated wastewater is achieved by the membranes – thus eliminating the need for secondary sedimentation (clarifier).

  • Significantly improving water quality due to the barrier effect of the membranes.

Technical advantages of MBR

  • Improved hygienic water quality by a factor of ~ 1000.
  • Reduced space requirement (approx. 50 %) due to elimination of secondary sedimentation (clarifier) and reduction of sludge tank volumes.
  • Retention of problematic substances such as microplastics, pathogens & antibiotic-resistant germs.
  • Reusability of the water.
  • Reach for further treatment, e.g. reverse osmosis.

Disadvantages of conventional MBR technology

Previous “conventional” MBR modules have the following disadvantages:

  • High energy consumption for flushing the membrane modules with air.
  • Additional pre-treatment of the wastewater (up to fine screening with < 1.0 mm fine sieves) in the influent of the treatment plant in order to remove hair and fibrous compounds that can get stuck in membrane modules due to their design (clogging!).
  • High space requirement for the membrane modules in some cases.
  • In an inefficient aeration system surplus air can cause oxygen contamination in downstream denitrification processes.

  • Costs for membrane replacement – membranes are wearing parts that have to be replaced after their service life has expired.
  • Cleaning and maintenance effort of the membrane filters at regular intervals.