Membrane Bioreactor (MBR)
Biological wastewater treatment and membrane filtration in one compact process
How an MBR works
From wastewater to high-quality treated water
A membrane bioreactor (MBR) combines biological wastewater treatment with membrane filtration to produce high-quality treated water. This makes them ideally suited for municipal wastewater treatment and industrial wastewater treatment.
First, microorganisms in the bioreactor break down organic matter and other pollutants in the wastewater.
The water then passes through microfiltration or ultrafiltration membranes. These membranes act as a physical barrier, retaining suspended solids, biomass and bacteria while allowing treated water, or permeate, to pass through.
Unlike conventional activated sludge treatment, an MBR does not rely on sludge settling in a secondary clarifier. This makes it possible to separate treated water from the biomass directly through the membranes.
Smaller plant footprint
No secondary clarifier is required.
Higher biomass concentrations
More treatment within the available tank volume.
Stable solids separation
Separation does not depend on how well the sludge settles.
High-quality treated water
Low-solids effluent suitable for discharge or as a basis for further water reuse treatment.
Two main membrane bioreactor configurations
Membrane bioreactors can be designed in two main ways, depending on where the membranes are positioned in relation to the biological treatment process.
Submerged MBR (sMBR)
In a submerged MBR, the membranes are installed directly in the membrane tank and operate while immersed in the mixed liquor.
Air is introduced beneath the membranes to maintain circulation and help control fouling at the membrane surface. Because filtration takes place directly in the tank, no external membrane loop is required, resulting in a compact configuration with relatively low pumping requirements.
This combination of compact design and lower recirculation demand is one of the main reasons submerged MBRs are widely used for municipal and industrial wastewater treatment.
Side stream MBR (ssMBR)
In a side stream MBR, the membranes are installed outside the bioreactor. Mixed liquor is pumped from the biological treatment tank through the membrane system and then returned to the process.
Side stream systems typically use higher crossflow velocities to control fouling, which can result in higher pumping energy requirements. At the same time, locating the membranes outside the tank can make them more accessible for inspection and maintenance.
BLUE FOOT IPC® technology for submerged MBRs
BLUE FOOT IPC® membranes are designed for submerged MBR systems, building on the compact configuration and low pumping requirements that make submerged membrane bioreactors attractive for municipal and industrial wastewater treatment.
At the core of each membrane is a non-compressible 3D woven support structure. The PVDF membrane layer is cast directly into this structure, creating a single integrated composite with an internal permeate channel. This robust construction enables the membrane to withstand mechanical stress while allowing effective backwashing across the membrane surface.
True backwash capability helps remove fouling and recover permeability during operation. Combined with controlled aeration, this supports stable filtration, higher sustainable flux and reliable long-term performance, while reducing the need for intensive cleaning and operator intervention.
3D Woven support
True backwash capability
Stable filtration
Higher sustainable flux
Ready to get more from your MBR?
Whether you are designing a new MBR, upgrading an existing installation or replacing membrane technology, we can help you find the right configuration for your treatment requirements, available footprint and future capacity needs.