WTO Chemical Feed Systems & Dosing

Question 1

What is the standard conversion factor used to calculate chemical feed rates in pounds per day from a dosage in mg/L and flow in MGD?

Accepted Answer

8.34

Answer

3.785

Answer

7.48

Answer

2.31

Question 2

A treatment plant processes 3 MGD and must apply 12 mg/L of alum. How many pounds of alum are required per day?

Accepted Answer

300.24 lbs/day

Answer

250.0 lbs/day

Answer

300.0 lbs/day

Answer

360.0 lbs/day

Question 3

Which type of chemical feeder is most appropriate for feeding powdered activated carbon (PAC)?

Accepted Answer

Dry chemical feeder

Answer

Solution feeder

Answer

Gas feeder

Answer

Peristaltic pump

Question 4

What is the primary purpose of a day tank in a chemical feed system?

Accepted Answer

To dilute concentrated chemicals and provide a measured daily supply

Answer

To store bulk chemicals for long-term use

Answer

To neutralize chemical spills in the feed area

Answer

To measure chemical demand in the raw water

Question 5

What is the EPA-recommended target concentration for fluoride in drinking water, updated in 2015?

Accepted Answer

0.7 mg/L

Answer

1.0 mg/L

Answer

0.5 mg/L

Answer

1.5 mg/L

Question 6

A solution feeder pumps 60 gallons per day of a 5% sodium hypochlorite solution. What is the daily feed rate in pounds of hypochlorite solution?

Accepted Answer

25.02 lbs/day

Answer

3.0 lbs/day

Answer

15.0 lbs/day

Answer

25.0 lbs/day

Question 7

Which chemical is commonly used as a primary coagulant in water treatment?

Accepted Answer

Ferric sulfate

Answer

Sodium fluoride

Answer

Potassium permanganate

Answer

Sodium hydroxide