Why MBR Membrane System Design Matters
When planning an MBR (Membrane Bioreactor) system, good design is critical. Whether you’re working on municipal wastewater or industrial reuse projects, a well-designed system saves cost, reduces downtime, and extends membrane life. In this article, we break down 7 key factors you should consider when designing or purchasing an MBR membrane system.
1. Fouling Resistance: Sludge Load & Membrane Layout
For better fouling resistance, the MBR system should:
- Keep sludge concentration under 10g/L.
- Arrange membrane modules for easy access and maintenance.
- Use conservative flux for industrial wastewater—usually about half of domestic wastewater flux. Always adjust based on specific wastewater quality.
➡️ Learn more about flux optimization in MBR systems (ACS Publications).
2. Membrane Material & Configuration
Membrane material matters. Common choices include:
- PVDF (most widely used), PP, PES, PTFE
- Configuration:
- Hollow fiber membranes (submerged type)
- Flat sheet membranes (costlier)
- Tubular membranes (external setup, highest cost)
The right choice depends on your application and budget.
3. Operating Cost & Energy Efficiency
Energy cost is a major factor. Things to consider:
- Pumps: Match to membrane design and TMP.
- Aeration:
- Large bubbles for membrane cleaning
- Fine bubbles for biological aeration
- For small MBRs, combined aeration may work, but higher energy use.
- For mid/large-scale, separate aeration systems are better for efficiency.
- Too much aeration shortens membrane life.
- Cleaning: Minimal cost.
- Membrane replacement: Depends on material, brand, and maintenance.
4. Blowers and Aeration Pipes
- Use oil-free blowers to protect membranes.
- For industrial wastewater, make sure to allow enough oxygen and have extra blower capacity.
- Aeration pipes tend to clog—include cleaning systems in your design.
- Prevent backflow from cleaning water into the blower by elevating air piping.
5. Automation & Monitoring
Most modern MBRs use PLC control systems, which manage:
- Auto valves (with feedback signals)
- Chemical dosing
- TMP, turbidity, and water quality monitoring
This reduces human error and keeps operations efficient.
6. Odor, Noise & Humidity Control
Because of the high aeration rate, MBR rooms can get smelly, noisy, and humid. Here’s how to fix it:
- Use odor control systems like centrifugal fans and sealed tank covers.
- Noise: Use noise-proof blowers or acoustic covers.
- Humidity: Add dehumidifiers or improve ventilation.
- Temperature: Keep under 40–45°C for membrane protection.
7. Color Issues & Removal
MBR membranes are usually microfiltration/ultrafiltration types. They don’t remove small color-causing molecules well. Solutions:
- Pretreatment: Add coagulants or decolorizers.
- Post-treatment: Use ozone or activated carbon to reduce color.
- For tough wastewater (e.g. landfill leachate or dye factories), consider adding NF/RO membranes downstream for better color control.
➡️ More on color removal in wastewater.
Conclusion
A good MBR system is more than just membranes—it’s about thoughtful design, efficient operation, and long-term savings. Whether you’re an engineer, contractor, or end user, understanding these design principles can help you make better decisions and avoid common pitfalls.
If you’d like a personalized recommendation or need help choosing the right MBR membrane for your system, contact us today.
