The innovative M.B.R. method for Wastewater Treatment and Reuse



The method is based on the principles of activated sludge system with the main difference lying on the replacement of the final sedimentation tank with membrane systems for the separation of the mixed liquid.

ParameterActivated sludgeM.B.R.
Typical biomass concentrations in bioreactors3-5 kg/m38-10 kg/m3
Mixed liquor separation methodCoagulation and sedimentation of suspended solidsFiltration through porous medium
Effluent qualitysecondarytertiary
BOD ≤ 25 mg/lBOD ≤ 10 mg/l
SS ≤ 15 mg/lSS ≤ 2 mg/l



  • Reduces volume required => reduction of footprint
  • Production of high quality effluent, suitable to be reused for irrigation (compliance with Greek legislation)
  • Excellent adjustment to fluctuations in incoming loads
  • Elimination of sludge settleability problems
  • Reduction of waste sludge produced

MESOGEOS applies the MBR method for:

  • Construction of new municipal and other wastewater treatment plants (industrial, landfill leachate, etc.)
  • Extensions of existing wastewater treatment plants with limited area available for expansion
  • Upgrades of existing wastewater treatment plants to improve effluent quality each time using the appropriate membranes type with the optimal system design for each use (available land, technology applied in case of an existing facility, climatic – surveying project data etc.)

Case Sudy:


MESOGEOS applied the MBR method for the retrofit of the existing WWTP of Aigio city with a capacity of 70,000 people.

More specifically, the project includes:

  • New pretreatment unit in order to protect downstream membranes.
  • New biological treatment unit with the method of membrane bioreactors (MBR). The new biological step consists of separate denitrification and aeration tanks and separate membranes immersion tank for separating the mixed liquid. KUBOTA membranes are used.
  • Chemical phosphorus removal unit
  • Upgrading – Expansion of disinfection unit
  • Upgrading – Expansion of sludge treatment plant.

Project Data :

Budget10.295.200 € + VAT
InfluentMunicipal waste water
New line capacity30.000 pe
New line capacity6.680 m3/day
Incoming organic load2.458 kg BOD/day
368 mg/l
Effluent qualityBOD = 15 mg/l
TSS = 5 mg/l
TN = 10 mg/l
Waste sludge production516,5 tn SS/year