... process of Water Purification plant :1. Raw water pump-- provide the pressure to silica sandfilter/active carbon filter 2. Silica Sand ... matter, colloid and so on 3. Active Carbon filter--Remove the color, free chloride, organic matter, harmful matter and so on ... any deposition of large Particles, most of the bacteria, and viruses into the RO membrane, The accuracy is 5um, for holding back any large ...