Assignment 14 Math Worksheet

Below are hints to help you work the problems in assignment 14.

1. Determine the chlorinator setting (lbs/day) needed to treat a flow of 2.5 MGD with a chlorine dose of 3.7 mg/L.

*Hint* Use the following formula:

(mg/L Cl2) x (MGD Flow) x (8.34 lbs/gal) = lbs/day Cl2

2. A flow of 745,000 gpd is to receive a chlorine dose of 8.4 mg/L. What should the chlorinator setting be (in lbs/day)?

*Hint* Use the following formula:

(mg/L Cl2) x (MGD Flow) x (8.34 lbs/gal) = lbs/day Cl2

3. A chlorinator setting is 25 lbs per 24 hours. If the flow being chlorinated is 1.89 MGD, what is the chlorine dosage expressed as mg/L?

*Hint* Use the following formula:

(mg/L Cl2) x (MGD Flow) x (8.34 lbs/gal) = lbs/day Cl2

4. A water is tested and found to have a chlorine demand of 2.3 mg/L. If the desired chlorine residual is 0.9 mg/L, what is the desired chlorine dose in mg/L?

*Hint* Use the following formula:

Chlorine Dose = Chlorine Demand + Chlorine Residual

5. What should the chlorinator setting be (lbs/day) to treat a flow of 2.85 MGD if the chlorine demand is 2.9 mg/L and a chlorine residual of 0.7 mg/L is desired?

*Hint* Use the following formula:

Chlorine Dose = Chlorine Demand + Chlorine Residual

6. If the chlorine dose is 2.8 mg/L to treat a flow of 2.25 MGD, what is the dosage (feed rate) in lbs/day?

*Hint* Use the following formula:

(mg/L Cl2) x (MGD Flow) x (8.34 lbs/gal) = lbs/day Cl2

Questions 7-10 deals with the chlorine virtual lab.