Unit 3 - Water Treatment

Question 1

Out of these sources, which is likely to require the most treatment:
A. Aquifers
B. Lakes
C. Rivers
D. Above-ground reservoirs

Answer 1

C. Rivers

Question 2

In a “multiple barrier” approach to safe drinking water, which of these would be considered a barrier
A. River diversion
B. Budgeting costs
C. Consumer’s tap
D. Post-chlorination

Answer 2

D. Post chlorination

Question 3

Define the goal of the “multiple barrier” approach

Answer 3

To minimize the chance of compromising water quality in the treatment process

Question 4

True or False:
In the water treatment process, fluoride is usually added post-filter

Answer 4

True

Question 5

True or False:
When taking a bacteriological sample, always rinse the bottle with the sample water first.

Answer 5

False

The sample should represent water running from the tap in an undiluted manner

Question 6

Define the purpose of coagulant addition

Answer 6

Coagulant addition enables colloids to form larger, heavier particles which settle more rapidly

Question 7

True or False:
The raw water intake is a suitable chlorine injection point

Answer 7

False

Disinfection is usually done between filtration and storage

Question 8

True or False:
Water with low viscosity provides less resistance to particles settling through it

Answer 8

True

Question 9

Particles will settle faster at which temperature
A: -4°
B: 0°
C: 4°
D: 6°

Answer 9

D: 6°

Question 10

A single tank that contains the process of coagulation, flocculation, and sedimentation is known as what:

Answer 10

Up-flow clarifier

Question 11

The process of cleaning the filter bed and media is known as as what?

Answer 11

Backwashing

Question 12

Name the 3 types of media filters in increasing density

Answer 12

Sand, Anthracite, Garnet

Question 13

Which of these is NOT an effective form of disinfectant?
A: Ozone
B: Reverse Osmosis
C: Chlorine
D: UV Radiation

Answer 13

B: Reverse Osmosis

Question 14

What is a possible disadvantage of chlorine disinfection

Answer 14

The formation of disinfection byproducts (BPDs)

Question 15

This disinfection process has the following advantages:
Absence of colouration and taste, less BPD formation, and no handling of dangerous chemicals

Answer 15

UV Disinfection

Question 16

Excessive fluoride concentrations can cause this:

Answer 16

Dental fluorosis

Question 17

Lime and Soda Ash are used in water treatment to do this:

Answer 17

Remove agents of water hardness from the water

Question 18

This method of water aeration involves the upward movement of air through water

Answer 18

Diffused air aerators

Question 19

Sacrificial Anodes may be composed of which elements

Answer 19

Magnesium or Zinc

Question 20

What is the principle reason groundwater should be chlorinated?

Answer 20

To ensure protection against microbial contamination

Question 21

If backwash waste is released to the river. What is the appropriate action?

Answer 21

Collect and test samples. Report to regional authority