Automotive Journal

Water filters are used to separate impurities from water. This process can be done by using physical barriers, different chemical processes, or biological means. Filters are necessary for drinking, irrigation, and swimming pools.

There are many different types of common filters. There are media filters, which use sand to filter water as it moves from below the rock and sand to the surface. Screen filters, which utilize a screen that separate fine particles out of the water for irrigation among other things. Disk filters are the main water filters for irrigation. It is much like the screen filter, but instead of a screen it uses small disks stacked on top of each other in order to separate the impurities.

When raw water is in need of treatment slow sand filters can be used. They are usually a length of one to two meters deep. A layer of earth, called the Schmutzdecke layer, which uses bacteria and fungi to purify the water. Using this process exceptionally clean water is left on the surface of the earth.

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 process that applies pressure to a membrane in order to force water through, trapping the solvent. Most of the separation occurs within the outer layer of the membrane called the polymer matrix. This filtration process requires a great amount of pressure to be put upon the membrane. The membrane is known as a semi permeable, which means the membrane only allows a solute to pass through trapping 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 filtration is among the most beneficial ideas man has ever conjured. Early in human existence water filters were used to allow man to live in some of the most difficult of environments. It can only continue to prove its usefulness as we further discover all of its capabilities.