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.
It has outstanding advantages as followings:
Minimum pumping energy required, thus energy saving
Chemical resistance, wide PH range
Easy to operate & maintenance
Low investment cost
No phase change
No contaminant residue caused by chemical reaction
Recovery ratio up to 98%
UF had been wide applied in industries such as:
1. Surface Water Clarification
2. RO Pre-Treatment
3. Waste Water Treatment
Ultra filtration (UF) is a separation process by using membranes with pore sizes in the range of 0.1 to 0.001 micron. Typically, ultra filtration will remove high molecular-weight substances, colloidal materials, and organic and inorganic polymeric molecules. Low molecular-weight organics and ions such as sodium, calcium, magnesium chloride, and sulfate are not removed. Because only high-molecular weight species are removed, the osmotic pressure differential across the membrane surface is negligible. Low applied pressures are therefore sufficient to achieve high flux rates from an ultra filtration membrane.