WTO Chemical Feed Systems & Dosing 2

Question 1

What type of pump is most commonly used for metering chemicals in water treatment plants?

Accepted Answer

Diaphragm metering pump

Answer

Centrifugal pump

Answer

Vertical turbine pump

Answer

Submersible pump

Question 2

Which chemical is typically added to water to raise pH for corrosion control in the distribution system?

Accepted Answer

Lime (calcium hydroxide)

Answer

Carbon dioxide

Answer

Sulfuric acid

Answer

Alum

Question 3

When a 150-lb chlorine cylinder is being connected and there is risk of chlorine gas release, which personal protective equipment is required?

Accepted Answer

SCBA or supplied-air respirator with full-face protection

Answer

Latex gloves and safety glasses

Answer

Dust mask and chemical splash goggles

Answer

Face shield and chemical-resistant gloves only

Question 4

A gas chlorinator feeds at 8 lbs/day and plant flow is 2 MGD. What is the applied chlorine dose in mg/L?

Accepted Answer

0.48 mg/L

Answer

0.96 mg/L

Answer

1.20 mg/L

Answer

4.17 mg/L

Question 5

What does 'flow-paced' chemical feeding mean?

Accepted Answer

Automatically adjusting chemical feed rate proportional to plant flow

Answer

Feeding chemicals at a fixed rate regardless of flow changes

Answer

Feeding chemicals only during peak flow periods

Answer

Manually adjusting the feed rate once per shift

Question 6

Which chemical is used as an oxidizing agent for taste and odor control and iron/manganese removal in water treatment?

Accepted Answer

Potassium permanganate

Answer

Sodium fluoride

Answer

Calcium hypochlorite

Answer

Ferric chloride

Question 7

Sodium hypochlorite solution degrades most rapidly when exposed to which conditions?

Accepted Answer

High temperature and direct sunlight

Answer

Low temperatures and darkness

Answer

Neutral pH and cool temperatures

Answer

High pressure and low humidity