Membrane Bio Reactors (MBR)

Membrane Bio Reactors (MBR) in wastewater treatment is a combination technology between biological processes (bioreactors) and membrane separation processes to produce treated water with excellent quality.

Basic Principles

1. Bioreactor
   Wastewater is first treated biologically with microorganisms. This process is similar to an activated sludge system, where bacteria degrade organic matter, nitrogen, and other pollutants.

2. Membrane
   Afterward, the sludge and wastewater mixture is passed through a membrane (usually a microfiltration or ultrafiltration membrane). This membrane serves as a physical filter to separate clean water from sludge and suspended solids.

Advantages of MBR

• High effluent quality: The output water is clear, free of suspended solids, bacteria, and many organic pollutants.

• Smaller land footprint: As the conventional sludge settling process is replaced by membranes, the installation becomes more compact.

• Reuse capability: MBR produced water can be reused for irrigation, industrial cooling, or even as an initial stage for drinking water after advanced treatment.

Disadvantages/Challenges

• Higher operational cost: Large energy consumption for aeration and membrane washing.

• Membrane fouling: Membranes are often dirty (clogged) requiring regular cleaning by backwashing or chemicals.

• Initial investment is expensive compared to regular activated sludge systems.

Typical Applications

• Hospital sewage treatment plants

• Urban domestic sewage treatment

• Food & beverage industry

• Pharmaceutical industry

• Water reuse (e.g. for toilet flushing or landscape irrigation)