Media filter

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This article is about a type of water filter. For software filters used for decoding audio and video, see Filter (video).
Peat-Sand Filter in United States. The filter treats stormwater runoff from a residential area. Stormwater from streets is first routed to a small detention basin (rear of photo, behind berm), which removes coarse sediment. After filtration an under-drain piping system discharges the filtered water to an adjacent stream.

A media filter is a type of filter that uses a bed of sand, peat, shredded tires, foam, crushed glass, geo-textile fabric, crushed granite or other material to filter water for drinking, swimming pools, aquaculture, irrigation, stormwater management and other applications.

Filter design[edit]

One design brings the water in the top of a container through a "header" which distributes the water evenly. The filter "media" start with fine sand on the top and then graduatingly coarser sand in a number of layers followed by gravel on the bottom, in gradually larger sizes. The top sand physically removes particles from the water. The job of the subsequent layers is to support the finer layer above and provide efficient drainage.

Drinking water filtration systems[edit]

Municipal drinking water systems often use a rapid sand filter and/or a slow sand filter for purification.

Media filtration for stormwater[edit]

Media filter system for urban runoff

Media filters are used to protect water quality in streams, rivers, and lakes. They can be effective at removing pollutants in stormwater such as suspended solids and phosphorus. Sand is the most common filter material.[1][2] In other filters, sometimes called "organic filters," wood chips or leaf mold may be used.[3]

Media filtration for sewage and wastewater[edit]

Media filters are also used for cleaning the effluent from septic tanks and primary settlement tanks. The materials commonly used are sand, peat and natural stone fibre.

See also[edit]

References[edit]

  1. ^ Water Environment Federation, Alexandria, VA; and American Society of Civil Engineers, Reston, VA. "Urban Runoff Quality Management." WEF Manual of Practice No. 23; ASCE Manual and Report on Engineering Practice No. 87. 1998. ISBN 1-57278-039-8. Chapter 5.
  2. ^ Atlanta Regional Commission. Atlanta, GA."Georgia Stormwater Management Manual." Section 3.2.4: "Sand Filters." August 2001.
  3. ^ ibid., Section 3.3.3: "Organic Filter."