Rapid sand filters and controls on the left . " National Archives, 293652
2.
In 1934 the first rapid sand filter plant was built in Ayer Hitam in Penang.
3.
Rapid sand filters are typically designed as part of multi-stage treatment systems used by large municipalities.
4.
In 1985, a new rapid sand filter plant replaced it across First Street beside the reservoir.
5.
Between the late 1940s and the early 1960s, slow sand filters were replaced by more efficient rapid sand filters.
6.
Water treatment filters that can be backwashed include rapid sand filters, pressure filters and granular activated carbon ( GAC ) filters.
7.
The United States also introduced the rapid sand filter which were a derivation of filters used in the paper making industry.
8.
Rapid sand filters must be cleaned frequently, often several times a day, by fluidized and care must be taken not to wash away the media.
9.
However, because of a continuous growing population in communities, slow sand filters are being replaced for rapid sand filters, mostly due to the running period length.
10.
Growing demand for water in the early 1930s in Warsaw prompted the building of a Rapid Sand Filter Station, which treat the water from four intakes.