Anaerobic MBBR adds moving carriers to an anaerobic reactor so that slow-growing methanogenic and syntrophic bacteria are retained on the biofilm even at short hydraulic retention times. This approach combines the energy-positive advantage of anaerobic digestion — biogas production from organic matter — with the washout resistance that biofilm attachment provides.
Why add carriers to an anaerobic process?
Methanogens grow slowly, so suspended-growth anaerobic systems need long solids retention times and are sensitive to washout during hydraulic overloads. Attaching the biomass to carriers decouples the solids retention time from the hydraulic retention time, meaning the reactor can be smaller for the same load. The biofilm also provides a buffered micro-environment that can improve process stability against shock loads and temperature dips.
The concept is well documented in research, though full-scale anaerobic MBBR applications are less common than aerobic ones. Carrier density and mixing are different from aerobic reactors because there is no aeration — mechanical mixers or recirculation keep the carriers moving. Carrier materials and geometry must be compatible with anaerobic biogas production, and the reactor must be sealed to capture gas.
Key considerations
Anaerobic MBBR considerations (indicative — confirm per project)
| Parameter | Typical Value | Unit | Notes |
|---|---|---|---|
| Benefit | Biomass retention | — | Decouples SRT from HRT; resists washout. |
| Product | Biogas (CH₄ + CO₂) | — | Energy-positive organic removal. |
| Mixing | Mechanical / recirculation | — | No aeration — sealed reactor for gas capture. |
| Maturity | Research + niche full-scale | — | Less common than aerobic MBBR; confirm feasibility per project. |
Frequently Asked Questions
Is anaerobic MBBR widely used?
Does anaerobic MBBR produce biogas?
How is the reactor mixed without aeration?
Related Pages
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