The given diagram demonstrates how raw water is filtered by a slow sand filter.
Overall, in order to clean the water, the slow sand filter uses a monotonous process, beginning with putting the water in a separate area and ending with completed water.
At the beginning of the process, the raw water is put in a system with a separate bin to break pressure chamber. Then they move to next bin, which has a filter with two layers have sand and gravel. The water with impurities such as dirties and particles from the first bin are placed on the top. This is followed by filtering slowly by sand and gravel.
The first layer of this filter is sand with the thickness of 60 to 90 centimeters. After that, the water goes down to the gravel layer from 20 to 30 centimeters of thickness. After finishing, the completed water moves to the area called “underdrains”, which release the result of the filter into another bin. This is finished by letting the filtered water outside to use for various purposes.
