Ultrafiltration Function and Advantages
Whether for potable drinking water or the treatment of waste water, ultrafiltration systems provide numerous benefits due in part to the simplicity behind the physics and chemistry of the operations, but also in the low energy costs that are associated with operating a UF system. While there are numerous other types of filtration such as nanofiltration and microfiltration, ultrafiltration systems usually are compared to reverse osmosis, both processes for purifying water. Of course, both utilize different methods, have much different results, and seek to gain vastly different end products.
Filtration through Semi-Permeable Membranes
Nonetheless, both ultrafiltration and reverse osmosis use semi-permeable membranes. Semi-permeable membranes are barriers which only allow the passage of certain molecules, compounds, and substances that are of a specific diameter, of which are determined by the diameter of the pore itself within the barrier. Through the use of a semi-permeable membrane, microorganisms, chemicals, particulates, and organic materials can be removed from water sources. Below we will dive into the four advantages of ultrafiltration systems.
Effectiveness of Normal Water Pressure
One of the most important ultrafiltration systems benefits relates to the absence of high pressure that is required of reverse osmosis. In RO systems, the normal flow of water goes to areas of higher solute concentration, and as a result has to have high amounts of back pressure to counteract a natural process. In ultrafiltration, low levels of water pressure naturally push solutes out of sieves in membranes, resulting in a clean product without the expenditure of higher amounts of pressure. This is especially important in larger industries where the volume of water that needs to be purified can lead to staggering costs and energy expenditures.
Removal of Harmful Agents
Another one of the advantages of ultrafiltration systems involves its ability to remove harmful colloids, bacterial species, bacterial cysts, and some viruses and parasites such as the cryptosporidium and giardia species from the water. Standard pore sizes within the membranes of the ultrafiltration system are approximately 0.01 microns, which allows for these entities to be evacuated and removed from the water source. It should be noted that the advantages of ultrafiltration systems are inherent on being a pretreatment of water for reverse osmosis, which further purifies the product. Due to the pore size, ultrafiltration cannot separate dissolved salts or low molecular weight species; however, by utilizing UF systems prior to RO, it prevents fouling which would easily occur in RO systems alone.
Retaining Essential Minerals
One additional and surprising advantage of ultrafiltration lies in what is left over from filtrate. Reverse osmosis removes important and healthy minerals such as calcium and magnesium due to the greatly smaller pore diameter. When such essential minerals are removed from the water sources, the pH of the water drastically decreases to levels that can easily cause erosion and damage to pipes, potentially exacerbating already problems that might be apparent within piping systems.
Chemical Free Purifying
Lastly and perhaps one of the most important benefits of using ultrafiltration as compared to other methods of purifying water is the lack of chemicals that are involved in the process. From an environmental standpoint this translates to no chemicals being released into the environment and no pollution to the natural resources. Some of the types of chemical agents used in water purification include antifoams, biocides, coagulants, disinfectants, flocculants, and oxidizers, just to name a few. While effective in their function, residues and other harmful byproducts are produced through the use of each of these. Fortunately, ultrafiltration does not use these or any chemicals.
Advantages of Ultrafiltration Summarized
Water filtration is very important to the world as a whole, as we need it in everyday life for drinking and cleanliness. Ultrafiltration provides important advantages over other methods for helping to clean and purify water. Depending on the application, ultrafiltration might require supplemental processes, as is the case with potable drinking water, but can stand alone for many other purposes. Through the use of ultrafiltration systems, harmful agents can be removed, energy costs can significantly be decreased, piping infrastructure can remain intact, and chemical pollution will never be an issue. There are numerous other ultrafiltration systems benefits to the use of UF systems and those are surely to increase as demand for cost effective measures and green campaigns ramp up in the coming years.