Ultrafiltration (UF) is an important purification technology used for the production of high-purity water. When strategically combined with other purification technologies in a complete water system, UF is ideal for the removal of colloids, proteins, bacteria, pyrogens, and other organic molecules.
Ultrafiltration (UF) is a remarkable technology in which hydrostatic pressure forces high concentration solution against a specialized semi-permeable membrane filter to dramatically remove suspended solids. A semi-permeable membrane is a thin layer of material capable of separating substances when a driving force is applied across the membrane. Once considered a viable technology only for desalination, membrane processes are increasingly employed for removal of bacteria and other microorganisms, particulate material, and natural organic material, which can impart color, tastes, and odors to the water and react with disinfectants to form disinfection byproducts (DBP).
Ultrafiltration uses hollow fibers 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. Ultrafiltration is not fundamentally different from reverse osmosis, microfiltration or nanofiltration, except in terms of the size of the molecules it retains. UF can be used as pretreatment for reverse osmosis systems or as a final filtration stage for deionized water.
Basic Principle of Ultrafiltration
Ultrafiltration is a pressure-driven purification process in which water and low molecular weight substances permeate a membrane while particles, colloids, and macromolecules are retained. The primary removal mechanism is size exclusion, although the electrical charge and surface chemistry of the particles or membrane may affect the purification efficiency. Ultrafiltration pore ratings range from approximately 1,000 to 500,000 Daltons.
UF membranes are composed of a polymer, such as polysulfone or polyamide that is usually extruded into flat sheets or hollow fibers or cut into disks as required by the specific application. A small disk of UF membrane may be subject to rapid fouling and produce a low flow rate for many processes.
As a result, UF membranes are typically arranged in a configuration which maximizes surface area and reduces fouling by using a tangential flow design to reduce solute accumulation at the membrane surface. Tangential flow UF devices may be spiral wound cartridges containing several square feet of membrane wrapped onto a central core tube or hollow-fiber cartridges containing dozens of thin UF membrane fibers.
What is Ultrafiltration (UF) in terms of membrane filter technology?
Ultrafiltration (UF) is used to remove essentially all colloidal particles (0.001 to 1.0 microns) from water and some of the largest dissolved contaminants. The pore size in a UF membrane is mainly responsible for determining the type and size of contaminants removed. In general, membrane pore size range from 0.005 to 0.1 micron.
Ultrafiltration is used in:
Laboratory grade water purification
Drinking water treatment
Paint Recovery in the automotive industry
Desalting and solvent-exchange of proteins
Dialysis and other blood treatments
Advantages of Ultrafiltration
One simple step for both clarifying and disinfecting water
Ultrafiltration permits the clarification and disinfection of water in a single step. A membrane barrier acts like a filter for all particles over 10-20 nm in size: pollen, algae, bacteria, viruses, germs and organic molecules.
Pure water of consistently high quality
This technology guarantees water of consistently high quality, with no taste or odour, no matter what the quality or turbidity of the water source.
An environmentally friendly technology
The Ultrafiltration procedure is mechanical: it reduces treatment waste and the need to use chemicals, while conserving the mineral equilibrium of the water.
Electro plating industry
Iron and Steel (involving processing from ore/ integrated steel plants and or Sponge Iron Unit
Fermentation Industry (Distilleries, Maltries and Breweries)
Milk processing and dairy products (integrated project)
Automobiles industries (Integrated facilities)/ Automobiles servicing, repairing and painting (excluding only fuel dispencing)
Pulp and Paper industry
Slaughter House, Meat & Sea Food Industry
Food and Fruit Processing Industry
Textile Industries/ Man-made fiber (synthetic)/ Woolen Mills/Cotton/Yarn/ textile processing involving any effluent/ emission- generating process ,bleaching, dyeing, printing and scouring
Rice Mills with boiler/furnance and dry rice mills
Pesticide Manufacturing and Formulation Industry
Hotel Industry (Hotels (10 rooms and above) /Restaurants having 30 chairs & above)
Inorganic Chemical Industry
Edible Oil & Vanaspati Industry
Soda Ash Industry (Solvay process)
Lead acid battery manufacturing (excluding assembling & charging of acid lead batteries.
Ferrous and Non ferrous metal extraction involving different furnaces through melting, refining, reprocessing, casting and alloy making
Synthetic fibers including rayon, tyre cord, polyster filament yarn
Health care establishment (20 Beds & Above)
Manufacturing of Paints, Varnishes, pigments and intermediate (excluding blending/ mixing) etc.