Wastewater Certification Grade 4
Practice Test Questions and Answers |
Latest Version | 2025/2026 | Correct &
Verified
Why must sludge be treated before disposal?
a) To increase BOD
✔✔b) To reduce pathogens and odors
c) To increase turbidity
d) To raise pH
What is the purpose of an equalization basin?
a) Remove chlorine
b) Remove grit
✔✔c) Balance flow and load variations
d) Increase BOD
Which of the following is a common disinfectant in wastewater treatment?
a) Sodium hydroxide
1
,✔✔b) Chlorine
c) Lime
d) Fluoride
Why is pH monitoring important in wastewater treatment?
a) To measure BOD
✔✔b) To ensure chemical reactions work effectively
c) To remove solids
d) To control temperature
Which of the following is an indicator of organic pollution in water?
a) TSS
✔✔b) BOD
c) pH
d) Chlorine
What is the purpose of a clarifier in secondary treatment?
a) Aerate the water
2
,✔✔b) Separate biological solids from treated water
c) Remove large debris
d) Adjust pH
Why are bacteria important in wastewater treatment?
a) They increase turbidity
✔✔b) They break down organic matter
c) They remove grit
d) They add nutrients
Which of the following is a sludge stabilization method?
a) Sedimentation
b) Chlorination
✔✔c) Anaerobic digestion
d) Screening
Why is aeration important in the activated sludge process?
a) To remove grit
3
, ✔✔b) To supply oxygen to bacteria for decomposition
c) To settle solids
d) To remove nutrients
Which of the following could indicate wastewater bypass in a treatment plant?
a) Low chlorine residual
✔✔b) High BOD in effluent
c) High pH
d) Low TSS
What is the purpose of a bar screen?
a) Remove dissolved chemicals
✔✔b) Remove large floating solids
c) Adjust pH
d) Disinfect water
Why is screening used in wastewater treatment?
a) To remove dissolved chemicals
4
Practice Test Questions and Answers |
Latest Version | 2025/2026 | Correct &
Verified
Why must sludge be treated before disposal?
a) To increase BOD
✔✔b) To reduce pathogens and odors
c) To increase turbidity
d) To raise pH
What is the purpose of an equalization basin?
a) Remove chlorine
b) Remove grit
✔✔c) Balance flow and load variations
d) Increase BOD
Which of the following is a common disinfectant in wastewater treatment?
a) Sodium hydroxide
1
,✔✔b) Chlorine
c) Lime
d) Fluoride
Why is pH monitoring important in wastewater treatment?
a) To measure BOD
✔✔b) To ensure chemical reactions work effectively
c) To remove solids
d) To control temperature
Which of the following is an indicator of organic pollution in water?
a) TSS
✔✔b) BOD
c) pH
d) Chlorine
What is the purpose of a clarifier in secondary treatment?
a) Aerate the water
2
,✔✔b) Separate biological solids from treated water
c) Remove large debris
d) Adjust pH
Why are bacteria important in wastewater treatment?
a) They increase turbidity
✔✔b) They break down organic matter
c) They remove grit
d) They add nutrients
Which of the following is a sludge stabilization method?
a) Sedimentation
b) Chlorination
✔✔c) Anaerobic digestion
d) Screening
Why is aeration important in the activated sludge process?
a) To remove grit
3
, ✔✔b) To supply oxygen to bacteria for decomposition
c) To settle solids
d) To remove nutrients
Which of the following could indicate wastewater bypass in a treatment plant?
a) Low chlorine residual
✔✔b) High BOD in effluent
c) High pH
d) Low TSS
What is the purpose of a bar screen?
a) Remove dissolved chemicals
✔✔b) Remove large floating solids
c) Adjust pH
d) Disinfect water
Why is screening used in wastewater treatment?
a) To remove dissolved chemicals
4
