Slow Sand Filter

Slow Sand media Water filter

In the Water Treatment system as well as sewage treatment system  Slow sand filter is the large-scale water filtration methods. Slow Sand media water treatment filter  is very old type water filtration but very effective water treatment system. In the slow sand filter, water entering first through about 32 -36 inches of sand, then through a multi size layer of gravel (This layer is known as schmutzdecke, which is German for “dirty skin.”) before entering the under-drain.  The multi sized layer (schmutzdecke break down and removes organic particles from the water through the mechanism of biological action, adsorption and straining methods. The absorption of biological microorganism in sand filter media should be reformed by the backwash with water.

Uses of Slow Sand filters

1. Slow Sand filtration of water treatment process is very reliable which do not usually require coagulation/ flocculation before filtration. This Filtration rate is 0.0015 – 0.15 gpm/ft²
2. Water treatments Filtration of Sand Filter is Minimum operation and maintenance requirements.
3. Sand filter usually does not require chemical pretreatment.
4. Sand filter Large land area required for the construct.
5. Need to manually clean filters removing the top 2 inches of sand.
6. It is operated with Gravity force.
7. This filtration mechanism is Biological action, straining, and adsorption.
8. Slow sand filter is used in Small ground water treatment systems.