Ultra-Filtration (UF) is a kind of membrane filtration method. It is a filtration process which utilizes trans-membrane pressure differential to separate particles according to molecular weights.

By using hollow fibers UF membrane as filtration media, raw water particles which are smaller than “pore” of UF membrane will permeate through and collected as permeate; whilst, particles which are larger than UF membrane pore size will be separated as concentrate under certain pressure applied.

UF membrane is an asymmetric semi-permeable membrane made of high molecular material by special technology. Its' hollow fiber tube cover densely by micro-pores which allow solution flowing in or out the membraneunder the influence of pressure. UF membrane pore size range from 0.1 to 0.005 µm or molecular weight (200,000 to 10,000 Daltons) for different applications.

Generally, it is used to remove high molecular-weight substances, colloidal materials, bacteria, organic and inorganic polymeric molecules.

UF system requires ONLY 20% energy consumption of reverse osmosis system. Low operating pressures are sufficient to achieve high flux rates from UF membrane.