What is the BioSand Filter?
April 20, 2006
The BioSand filter works in the same way as traditional slow sand water filters, which have been used for centuries. The difference is that the BioSand filter is smaller, and water does not need to flow through it all the time. The filter can be built anywhere in the world because it is built using materials that are available. It is simply a concrete container, with layers of sand and gravel inside it. The sand and gravel remove dirt, bacteria, viruses and parasites and other impurities from the water.
How does it work?
Water is poured into the top of the filter whenever it is needed. There is a diffuser plate placed just above the sand bed that absorbs the shock of the falling water so it does not disturb the sand. Traveling slowly through the sand bed, the water then passes through several layers of gravel and collects in a pipe at the bottom of the filter. It is then pushed up through plastic piping that is encased in the concrete, and out of the filter, for the user to collect.