Ultra filtration (UF) is a membrane filtration process similar to Reverse Osmosis, using hydrostatic pressure to force water through a semi-permeable membrane. The pore size of the ultra filtration membrane is usually 103 - 106 Daltons. Ultra filtration (UF) is a pressure-driven barrier to suspended solids, bacteria, viruses, end toxins and other pathogens to produce water with very high purity and low silt density.
How It Works
Ultra filtration uses hollow fibres of membrane material and the feed water flows either inside the shell, or in the lumen of the fibers. Suspended solids and solutes of high molecular weight are retained, while water and low molecular weight solutes pass through the membrane. Ultra filtration is not fundamentally different from reverse osmosis, microfiltration or nanofiltration, except in terms of the size of the molecules it retains. When strategically combined with other purification technologies in a complete water system, UF is ideal for the removal of colloids, proteins, bacteria, pyrogens, proteins, and macromolecules larger than the membrane pore size from water.
- No need for chemicals (coagulants, flocculates, disinfectants, pH adjustment)
- Size-exclusion filtration as opposed to media depth filtration
- Good and constant quality of the treated water in terms of particle and microbial removal
- Process and plant compactness
- Simple automation
- Environmentally friendly
What does ultra filtration remove?
- End toxins
Ultra filtration systems contain extremely fine membrane filters which need to be properly cleaned. The cleaning process used depends on whether a UF system is being used to remove organic or inorganic contaminants, or even both. To remove organic contaminants the general cleaning protocol for the cleaning of tubular membranes is to use a low foam, medium alkaline detergent at 0.6% to 1% for a maximum of 40 to 60 minutes. To remove inorganic contaminants the best treatment is with citric acid at a maximum concentration of 3.0 %. The acid should circulate for 1 to 3 hours. Hydrochloric acid can also be used to clean membranes, as can oxalic, sulphuric and nitric acid.