Which of the following is the optimum coagu lation condition

Which of the following is the optimum coagu- lation conditions of pH and ferric dose? 1. pH 8.2 and dose of 0.001 mg/L 2. pH 5-6 and dose of 3-270 mg/L 3. pH 3-5 and dose of 3-270 mg/L 4. pH 3-9 and dose of 3-270 mg/L 5. pH 6-9 and dose of 10-270 mg/L ati

Solution

Option 2 is correct. When using iron, PH value should lie between 5-6. In this range chemicals will effectively work. And ferric dose should be 3- 270 mg/l.