A multi-media filter utilizes one or more filtration media to pass turbid water through a certain thickness of granular or non-granular material under pressure, effectively removing suspended impurities and clarifying the water. Common filter materials include quartz sand, anthracite coal, and manganese sand, primarily for removing suspended or colloidal impurities from water, especially fine particles and bacteria that sedimentation techniques cannot remove. It also offers some degree of removal for BOD5 and COD. Mainly used for water treatment to remove turbidity, soften water, and as pre-treatment for pure water, the effluent turbidity can reach below 3 degrees.
Multimedia filter materials can be glass fiber reinforced plastic, A3 steel with anti-corrosion coating or lined with rubber, or full stainless steel. Operation methods include fully automatic and manual forms.