1. the ratio of 80:20 an effective removal of the best 89.2 percent. 2. Ferric chloride (FeCl3) concentration 46 percent dilute left 0.46 percent 30 ml / L best. 3. Sodium hydroxide (NaOH) concentration 50 percent dilute left 5 percent 0.5 ml / L best. And the 4. Sodium hypochlorite (NaOCl) concentration 10 percent 0.3 ml / L best.