MBBR + membrane treatment places a micro- or ultrafiltration membrane downstream of the MBBR to provide an absolute barrier against suspended solids, bacteria and most pathogens. This combination delivers reuse-quality effluent with the operational simplicity of a pure MBBR (no sludge return) and the solids-free permeate of a membrane system.
How it differs from MBR
A conventional MBR (membrane bioreactor) immerses membranes directly in the activated-sludge mixed liquor and uses sludge return. MBBR + membrane is different: the MBBR operates with carriers and no sludge, and the membrane sits in a separate tank or external skid that filters the MBBR effluent. Because the membrane feed is much diluter (MBBR effluent, not mixed liquor), fouling can be lower and membrane flux higher, though a pre-separation step (e.g. screen or coarse filter) may be needed to protect the membrane from large biofilm fragments.
This configuration is used where the effluent must be virtually solids-free — for example water reuse, sensitive receiving waters, or as pre-treatment for reverse osmosis. It is more capital-intensive than MBBR + clarifier or MBBR + DAF, so it is typically specified only when the effluent standard demands it.
Design considerations
MBBR + membrane design (indicative — confirm per project)
| Parameter | Typical Value | Unit | Notes |
|---|---|---|---|
| Membrane type | MF or UF | — | Absolute barrier to solids and most pathogens. |
| Fouling | Lower than MBR | — | Dilute feed vs mixed-liquor feed. |
| Pre-screen | Recommended | — | Protects membranes from large biofilm fragments. |
| Application | Reuse / stringent limits | — | Specified when quality demands it. |
Frequently Asked Questions
Is MBBR + membrane the same as MBR?
When is MBBR + membrane needed?
Does the membrane need chemical cleaning?
Related Pages
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