Sand Filters

Rapid, pressure, up-flow and slow sand filters as a core step in water purification.

GENERAL

Sand filters are used as a step in the water treatment process of water purification.

There are three main types; rapid (gravity) sand filters, upward flow sand filters and slow sand filters. All three methods are used extensively in the water industry throughout the world. The first two require the use of flocculants chemicals to work effectively while slow sand filters can produce very high quality water with pathogens removal from 90% to >99% (depending on the strains), taste and odour without the need for chemical aids. Sand filters can, apart from being used in water treatment plants, be used for water purification in singular households as they use materials which are available for most people

Overall, there are several categories of sand bed filter:

  • rapid (gravity) sand filters
  • rapid (pressure) sand bed filters
  • up flow sand filters
  • slow sand filters