CWS Water Treatment Equipment & Technologies 2

Question 1

What is the primary purpose of a brine tank in a water softener system?

Accepted Answer

To store salt used for resin regeneration

Answer

The brine tank stores salt (sodium chloride or potassium chloride) which is dissolved into a brine solution used to regenerate the ion exchange resin.

Question 2

Which membrane process operates at the lowest operating pressure among the four main pressure-driven membrane technologies?

Accepted Answer

Microfiltration

Answer

Microfiltration operates at the lowest pressures (typically 5–45 psi) because it targets the largest particles — bacteria, sediment, and protozoa — requiring less driving force.

Question 3

In an ultraviolet (UV) disinfection system, what component must be monitored regularly to ensure effective microbial inactivation?

Accepted Answer

UV intensity sensor (or UV transmittance)

Answer

UV intensity sensors monitor the actual UV dose delivered; reduced transmittance from fouling or lamp aging directly lowers germicidal effectiveness.

Question 4

A carbon block filter is superior to a granular activated carbon (GAC) filter for removing chloramines primarily because:

Accepted Answer

The compressed block provides longer contact time with denser carbon

Answer

The compressed structure of carbon block filters forces water into closer, longer contact with the carbon media, improving chloramine reduction efficiency compared to the channeling that can occur in GAC beds.

Question 5

What is 'bypass hardness' in the context of residential water softening?

Accepted Answer

Hard water intentionally blended with softened water to raise final hardness slightly

Answer

Bypass hardness refers to a controlled blending of a small fraction of hard water into the softened water stream to achieve a target finished hardness above zero, often preferred for taste.

(CWS) Certified Water Specialist Practice Test

(CWS) Certified Water Specialist Practice Test

CWS Water Treatment Equipment & Technologies 2