Upgrade options compared
| Item | Details |
|---|---|
| Add tanks and clarifiers | simple process, but needs land and time. |
| IFAS or MBBR | adds biological capacity; clarifiers may still limit. |
| Convert to MBR | replaces clarifier separation with membranes, allowing higher MLSS in existing basins. |
| Expand an existing MBR | add membrane area or replace old membranes with higher-area modules. |
Custom sizing: we cut, weld and assemble in Poughkeepsie, NY, so cartridge and module sizes can often be tailored to your existing tanks. Tell us your tank dimensions, or see custom sizes.
What to check before converting
Aeration capacity is often the real limit at higher MLSS, so blowers and diffusers need review. Fine screening must be added if it is not there. Hydraulics, permeate pumping and controls change too. A capacity study with real flow and load data is the right first step; we can help with the membrane side and work with your engineer on the rest.
Interim capacity
US plants that need relief during design and construction can rent Zyramic modules. Plants already running flat-sheet MBR can often gain capacity by replacing old membranes with fresh ones, see replacement membranes.
| Mild backwash (special cases only) |
|---|
| Backwashing is not a standard Swing operating mode and is not meant for routine use. Swing has been pressure-tested to 14.5 psi (1 bar) and held without breaking. If a site is in a bind even after relaxation and CIP, contact us; we may be able to work out a special mild-backwash procedure. |
Worked sizing example
Take a plant rerated from 2,000 to 792,516 gpd (3,000 m³/day) in existing tanks:
| Item | US | Metric | Note |
|---|---|---|---|
| Average flow | 792,516 gpd | 3,000 m³/day | about 550 gpm (125,000 L/h) |
| Design flux (gross) | 11.8 gfd | 20 LMH | Zyramic design guidance |
| Derate for relaxation and cleaning | ~20% | ~20% | |
| Net flux | ~9.4 gfd | ~16 LMH | |
| Membrane area needed | ~84,093 ft² | ~7,812 m² | average flow ÷ net flux |
| Swing-8 cartridges | ~625 | ~625 | 135 ft² (12.5 m²) each |
| Peak factor | ~2.0 | ~2.0 | |
| Peak flow | ~1,585,032 gpd | ~6,000 m³/day | extra area, short-term higher flux, or equalization |
This is an illustration only; a real design also checks temperature, MLSS, redundancy and the cleaning schedule.
Tips for a smooth project
- Look for the root cause before increasing cleaning strength
- Use temperature-corrected permeability when judging membranes
- Check screens for bypasses after storms
- Plan replacements ahead of permit deadlines
Next step
Membrane issues are easiest to resolve early. Send your trend data, cleaning records and a few photos, and we will give you our read on whether to focus on pretreatment, biology, operation or the membranes themselves, and a sensible next step, whether that is a change in procedure, a partial replacement or interim capacity.
Sizing considerations
To give a useful recommendation we usually need:
- Current and design flows and loads
- Permit limits and any upcoming changes
- Tank volumes and drawings
- Blower and diffuser capacity
- Timeline, funding source and any domestic-content requirements
Most relevant product: Swing MBR. See also replacement membranes, rentals and how to choose.
Why engineers look at Zyramic flat-sheet modules
| Item | Details |
|---|---|
| Smaller sheets, less wear and tear | each sheet flexes less in service, and a damaged unit affects less area. |
| Strong wide membrane welds | designed to resist delamination over the membrane's life. |
| Thick, robust membrane | about 250 microns including support. |
| Assembled in Poughkeepsie, NY | of domestic and imported components. In our Poughkeepsie shop we cut and weld membrane sheets to plates, build module frames and assemble complete modules. For funded projects, tell us your domestic-content requirements and we'll review what we can document. |
| Buy, rent or replace | new modules, rentals and pilots for US projects, and replacement membranes that fit many existing cassettes. |
Performance and life depend on pretreatment, design flux and operation; flux figures are Zyramic design guidance, sized to each project.
Frequently asked questions
How much more capacity can an MBR conversion give?
It depends on aeration, loading and tank geometry. Many conversions raise capacity significantly, but only a study can confirm a number.
Can it be done while the plant runs?
Often in phases, train by train.
Can you meet domestic-content requirements?
Our modules are assembled in the USA of domestic and imported components. Tell us your domestic-content requirements and we'll review what we can document.
Can rentals bridge the gap?
Yes, for US projects, subject to availability.
Is MBR the cheapest way to add capacity?
Not always. It often wins where land is limited or effluent limits are tightening. A study comparing options is worthwhile.
Will a conversion improve effluent too?
Usually, because the membrane provides a physical barrier to suspended solids.