14:46 Banott Water Treatment Engineering Team — Published August 28, 2026
Sizing a submerged hollow fiber MBR train means converting a design flow into a required membrane area, then dividing that area by the area of one module. Banott’s hollow fiber modules span 3 m² (MBRIII3C), 10 m² (MBRIII10C), and 20 m² (MBI120C); design flux, TMP range, and CIP conditions are confirmed as not yet published and must be requested directly.
Submerged MBR Membrane Modules: Specs and Sizing
A submerged configuration places the membrane module directly in the mixed liquor tank, with permeate pulled through the fiber wall under vacuum rather than pumped across the membrane surface under pressure. That distinction matters for sizing because the driving force is limited — typical submerged systems run well below the TMP ceilings used in pressurized ultrafiltration, which is part of why fouling control and aeration design carry more weight in the sizing conversation than in a pressurized skid.
This is not a definition article, so the rest of this piece assumes the reader already knows what MBR is and moves straight into the module-count math.
Three numbers determine how many modules a train needs:
The relationship is:
Required total membrane area (m²) = Design flow (m³/day) ÷ [Design flux (L/m²·h) × 24 ÷ 1,000]
Module count = Required total membrane area ÷ Effective area per module
Design flux is the term that carries the most engineering judgment in this equation, because it has to account for peak-to-average flow ratios, temperature, mixed liquor suspended solids concentration, and the fouling margin the designer wants to hold in reserve. It is also the parameter Banott has not yet published for the hollow fiber MBR line — see the flagged gap below before running this formula against a real project.
| Modello | Area effettiva della membrana | Configuration | Design flux | TMP range | Aeration/scour rate | Module dimensions | CIP protocol |
| MBRIII3C | 3 m² | Submerged hollow fiber | Not published — available on enquiry | Not published — available on enquiry | Not published — available on enquiry | Not published — available on enquiry | Not published — available on enquiry |
| MBRIII10C | 10 m² | Submerged hollow fiber | Not published — available on enquiry | Not published — available on enquiry | Not published — available on enquiry | Not published — available on enquiry | Not published — available on enquiry |
| MBI120C | 20 m² | Submerged hollow fiber — classification pending confirmation | Not published — available on enquiry | Not published — available on enquiry | Not published — available on enquiry | Not published — available on enquiry | Not published — available on enquiry |
The MBI120C’s naming pattern resembles Banott’s flat sheet series even though the resource library lists it under hollow fiber; this has not been resolved with the product team, so specify it with that caveat until confirmed.
Submerged MBR Membrane Modules: Specs and Sizing
With effective area confirmed but design flux unconfirmed, the second half of the formula above has no right-hand side to solve. A worked example plugging in an assumed flux number would look complete on the page and be wrong in a tender submission — exactly the failure mode a design institute reader cares about most. Rather than estimate a plausible-looking LMH figure, this article stops at the formula and the confirmed area inputs, and treats the flux value as a request-for-data item.
Once design flux, TMP range, and aeration rate are confirmed, the worked example that belongs here is straightforward: pick a design flow, divide by flux to get area, divide by module area to get count, then round up to the next whole module and add any standby units the redundancy philosophy calls for.
A frequent sizing error is using a module’s rated maximum flux as the design flux for the whole train. Rated maximum flux is a short-term, clean-water figure; running a submerged MBR at that rate continuously against real mixed liquor accelerates fouling and shortens the interval between chemical cleans. The design flux used for module-count math should sit below the rated maximum, with the margin sized against the specific wastewater’s fouling tendency — which is one more reason this figure has to come from Banott’s engineering team against actual influent data rather than from a generic catalog number.
Module count only answers part of the sizing question. Two upstream conditions have to be in place before any submerged hollow fiber module count is meaningful:
Skipping either prerequisite is a common reason a correctly module-counted train still underperforms once commissioned.
Submerged MBR Membrane Modules: Specs and Sizing
Compared with adding filtration downstream of a conventional activated sludge process, submerged MBR module sizing folds the clarification step directly into the biological tank rather than adding a separate polishing stage. That collapses two design decisions — secondary clarifier sizing and effluent polishing — into one membrane-area calculation, which is part of why MBR retrofits can fit inside an existing tank footprint where a conventional secondary clarifier upgrade could not.
A: No. Area alone only gives the denominator. Design flux — not yet published for this product line — is required to calculate the required total area in the first place.
A: Banott’s resource library currently lists it under hollow fiber MBR with 20 m² effective area, but the model naming pattern matches the flat sheet series. This has not been resolved with the product team and should be confirmed before specifying it in a tender document.
A: Redundancy philosophy (N+1 module, standby train, or no standby) is a project-specific design decision made with Banott’s engineering team against the plant’s criticality and maintenance access, not a fixed rule this article can state generically.
A: No public per-module price is available; pricing requires a direct enquiry.
How to size a submerged hollow fiber MBR train from design flow to module count, with confirmed module area, screening and aeration prerequisites, and gaps flagged where flux and TMP data are pending.
How to size a compact RO system beyond the nameplate GPD figure — feed TDS, temperature derate, and duty cycle, applied to Banott's published 300–3,000 GPD range.
