... ro water purifier Function 1. 5 micron PP filter (pp) : remove the particles, dust, mud, etc. 2. Granular ... carbon filter (GAC/UDF): remove the chlorine, odor smell, organics, turbidity etc. 3. Block carbon filter (CTO): remove the chlorine, odor ... smell & suspending particles. 4. RO membrane : remove the bacteria, heavy metal, ...