Hollow-fibre and Multibore ultrafiltration modules separate by physical size rather than by chemistry, so removal of particulate, turbidity and microorganisms is governed by pore size and membrane integrity rather than by feed water chemistry.
Pore size and what it removes
These modules run a nominal pore size of 0.02–0.03 µm, which is an absolute barrier to particulate, most bacteria and — at the tighter end — viruses. Because separation is physical, performance does not depend on the ionic makeup of the feed the way an RO element's does.
Membrane area and module selection
Active membrane area runs roughly 38–80 m² (409–861 ft²) per module. The number in the model name is the area in m². Module count follows from design flux and the feed water, not from area alone.
Flux and recovery are design outputs, not specifications
Sustainable flux depends on feed quality, temperature and the backwash and chemically-enhanced backwash regime. Use the manufacturer's process design manual for the specific module family rather than a rule of thumb.
Integrity testing
A hollow-fibre barrier is only as good as its integrity. Systems relied on for pathogen removal need periodic pressure-decay or equivalent integrity testing, and a documented response when a test fails.
RO pretreatment duty
The most common use here is protecting downstream RO. UF gives a consistent low-SDI feed largely independent of raw water swings, which is what lets an RO train hold its design flux.