A plant treating 5 MGD with 40 lbs/day of chlorine has a chlorine dose of how many mg/L?

A plant treating 5 MGD with 40 lbs/day of chlorine has a chlorine dose of how many mg/L?

• A. 0.6 mg/L
• B. 1.2 mg/L
• C. 1.5 mg/L
• D. 0.8 mg/L

Answer: (D)

Chlorine dose in mg/L is the mass of chlorine delivered per day divided by the volume of water treated per day. Convert to consistent units and divide. 40 pounds per day equals about 18,143,694 mg/day. The plant treats 5 million gallons per day, and one US gallon is about 3.78541 liters, so the daily volume is roughly 5,000,000 × 3.78541 ≈ 18,927,050 liters per day. Dose = 18,143,694 mg/day ÷ 18,927,050 L/day ≈ 0.96 mg/L. The closest value to 0.96 mg/L among the options is 0.8 mg/L, so that is the best pick.

Chlorine dose in mg/L is the mass of chlorine delivered per day divided by the volume of water treated per day. Convert to consistent units and divide.

40 pounds per day equals about 18,143,694 mg/day. The plant treats 5 million gallons per day, and one US gallon is about 3.78541 liters, so the daily volume is roughly 5,000,000 × 3.78541 ≈ 18,927,050 liters per day.

Dose = 18,143,694 mg/day ÷ 18,927,050 L/day ≈ 0.96 mg/L.

The closest value to 0.96 mg/L among the options is 0.8 mg/L, so that is the best pick.