If an operator is feeding alum at a rate of 12 mg/L and the plant flow is 4,200 gpm, how many pounds per day is being fed?

If an operator is feeding alum at a rate of 12 mg/L and the plant flow is 4,200 gpm, how many pounds per day is being fed?

• A. 606
• B. 290
• C. 165
• D. 452

Answer: (A)

To determine the amount of alum being fed in pounds per day, you need to convert the feed rate from mg/L to pounds and account for the flow rate of the water being treated. 1. **Calculate the daily flow in gallons**: Since the plant flow is 4,200 gallons per minute, you need to find the total flow for a day. There are 1,440 minutes in a day (24 hours x 60 minutes). Therefore, the daily flow would be: \[ 4,200 \, \text{gpm} \times 1,440 \, \text{minutes/day} = 6,048,000 \, \text{gallons/day} \] 2. **Convert gallons to liters**: Knowing that 1 gallon is approximately 3.78541 liters, you can convert the daily flow to liters: \[ 6,048,000 \, \text{gallons/day} \times 3.78541 \, \text{liters/gallon} \approx 22,890,816 \, \text{liters/day} \] 3. **Calculate the total mass of alum in mg/day**

To determine the amount of alum being fed in pounds per day, you need to convert the feed rate from mg/L to pounds and account for the flow rate of the water being treated.

1. Calculate the daily flow in gallons: Since the plant flow is 4,200 gallons per minute, you need to find the total flow for a day. There are 1,440 minutes in a day (24 hours x 60 minutes). Therefore, the daily flow would be:

[

4,200 , \text{gpm} \times 1,440 , \text{minutes/day} = 6,048,000 , \text{gallons/day}

]

2. Convert gallons to liters: Knowing that 1 gallon is approximately 3.78541 liters, you can convert the daily flow to liters:

[

6,048,000 , \text{gallons/day} \times 3.78541 , \text{liters/gallon} \approx 22,890,816 , \text{liters/day}

]

3. Calculate the total mass of alum in mg/day