A jar test indicates an optimal coagulant dose of 12 mg/L with rapid mix for 30 seconds and slow mix for 15 minutes. How should this be implemented in full-scale operation?

A jar test indicates an optimal coagulant dose of 12 mg/L with rapid mix for 30 seconds and slow mix for 15 minutes. How should this be implemented in full-scale operation?

• A. Apply a different dose and bypass plant trials.
• B. Ignore hydraulic conditions and rely on jar test alone.
• C. Apply the same coagulant dose and rapid mixing for ~30 seconds followed by slow mixing for ~15 minutes.
• D. Apply the same coagulant dose and ensure rapid mixing for ~30 seconds followed by slow mixing for ~15 minutes; adjust for plant hydraulic conditions and verify with plant trials.

Answer: (D)