Hiekkasuodatusta

Hiekkasuodatusta, or sand filtration, is a physical water purification process that uses sand as a filtering medium to remove impurities from water. It is a common method used in both municipal water treatment plants and in smaller scale applications such as swimming pool filters and domestic water filters. The process works by passing water through a bed of sand, which traps suspended solids, sediment, and other particulate matter.

The effectiveness of sand filtration depends on several factors, including the grain size of the sand, the depth of the filter bed, and the flow rate of the water. Finer sand grains can capture smaller particles, but they also increase resistance to flow. Deeper filter beds provide more surface area for filtration and can therefore handle higher volumes of water. Controlling the flow rate is crucial to ensure adequate contact time between the water and the sand, allowing for efficient removal of contaminants.

Sand filters are typically backwashed periodically to remove the accumulated debris. This involves reversing the flow of water through the filter bed, flushing out the trapped impurities. The backwash water is then discharged or further treated. Over time, the sand may need to be replaced or replenished to maintain optimal filtration performance. Sand filtration is a relatively simple, cost-effective, and reliable method for improving water clarity and reducing turbidity.