How Water Filters Function
Water filtration is the process of separating impurities from water. We are able to make this process work using water filters. Filtration can be done using physical barriers, different chemical processes, or biological processes. Filters are used to purify drinking water, swimming pools, and irrigation.
There are many different forms of filtrating water. A media filter can be used, which uses sand to filter water as it travels from below the ground to the surface. Screen filters; utilize a flexible screen that separates fine particles out of the water for several uses, such as irrigation. The main form of filtering water for irrigation is using disk filters. This process is very similar to screen filtering except instead of a screen small disks are stacked on top of one another allowing the water through and trapping the impurities.
Slow sand filters are used when raw water is needed to be treated. They usually extend one to two meters underground. The Schmutzdecke layer, which uses bacteria and fungi to purify the water, allows the water to pass through on its way to the surface. This process produces exceptionally clean water that is left on the surface of the ground.
Rapid sand filters or rapid gravity filters are forms of filtration used municipal water treatment facilities. Coarse sand is used to remove the particles that were previously trapped in flocks by salts of aluminum or iron. The simplest filter still in use today is the cloth filter. This filter can be dangerous because it is not very effective. It is done by using a folded cloth placed in a container. The container is dipped in water and then raised. The cloth is lifted from the container and the filtered water will move through the cloth and into the container.
Filtration has several more complex forms that do not employ physical screens in order to filter the impurities out of water. Using ultra violet rays, water can be purified very effectively. Exposing water to the rays will remove any virus and bacteria that would have previously been in the water. Raw water is normally put through this process but drinking water has more recently been filtered in this way. A drinking water disinfection facility has already been approved for construction in New York that will use ultra violet rays. The facility should be able to produce up to two billion gallons of drinking water on a daily basis.
Reverse osmosis is a filtration process that uses applied pressure to force a solution through a membrane that traps the solute and allows the solvent, in this case water, to pass move through to the other side. Most of the separation occurs in the outer layer in the polymer matrix. This filtration process requires a great amount of pressure to be forced on one side of the membrane. The membrane is known as semi permeable, which means is only allows the passage of the solute and not the solvent.
Catalytic converters are devices that use filtration as a means to filtrate the gases that are expelled by automobiles. The converter is placed upon the automobile in order to reduce its toxic emissions that could damage the environment.
Water filters are one of the most important devices man has ever invented. Primitive forms of these filters allowed man to survive in the harshest of climates. There will never be a time that people are not in need of water filters as a means of survival. Further research into this filtration can only prove itself worthwhile and beneficial.
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