Wastewater Operator certification
Study Guide-Grade 2 Latest 2026-
2027. Questions & Correct Verified
Answers. Graded A
Activated Sludge:
Adequate ___BOD, ____nitrogen, ____Phosphorous ratio for
microorganisms to grow is usually
a. 100:2:1
b. 100:5:1
c. 100:10:3
d. 100:12:5 - ANS100:5:1
Activated Sludge:
At what concentration level should dissolved oxygen be maintained during
the initial start up of a oxidation ditch? _____? - ANS2.0 mg/L
Activated Sludge:
Bacteria are in the ______kingdom - ANSMonera Kingdom
Activated Sludge:
1
,Following the activated sludge what process modification is very sensitive
to bulking?
a. conventional modification
b. extended aeration activate sludge
c. complex mix aeration
d. pure oxygen - ANSconventional modification
Activated Sludge:
Grease should be cleaned from walkaways with a stiff brush and
a. detergent
b. bleach
c. trisodium phosphate
d. phosphate-free surfactant - ANStrisodium phosphate
Activated Sludge:
How much of the solids should be wasted each week in the summer form a
package wastewater treatment plant for the best quality? - ANS5%
Activated Sludge:
If an activated sludge plant is hit with a high organic load, what will most
like occur in the aeration tank? - ANSsignificant decrease in DO
Activated Sludge:
2
,In a small package, wastewater treatment plant, the operator should try to
keep the dissolved oxygen in the aeration tank at approximately:____mg/L
- ANS2.0 mg/L
Activated Sludge:
Mixed liquor is a combination of what 3 things? - ANSactivated sludge in an
aeration tank
+
primary effluent
+
return sludge/raw wastewater
Activated Sludge:
Most algae are in the____kingdom - ANSProtista Kingdom
Activated Sludge:
Of the following, which is the least important nutrient in wastewater
treatment for microorganisms to reproduce?
a. potassium
b. nitrogen
c. carbon in organic matter
d. phosphorous - ANSpotassium
3
, Activated Sludge:
Primary treatment is not required in which modified activated sludge
process?
a. step aeration
b. complete mix aeration
c. tapered aeration
d. extended aeration activated sludge - ANSextended aeration activation
sludge
Activated Sludge:
What is the critical factor in any method to control the aeration tank?
a. BOD
b. F/M
c. COD
d. DO - ANSF/M ratio
Activated Sludge:
What is the most accurate measure of the organisms present in an aerator
for treating incoming wastes? - ANSMLVSS
Activated Sludge:
4
Study Guide-Grade 2 Latest 2026-
2027. Questions & Correct Verified
Answers. Graded A
Activated Sludge:
Adequate ___BOD, ____nitrogen, ____Phosphorous ratio for
microorganisms to grow is usually
a. 100:2:1
b. 100:5:1
c. 100:10:3
d. 100:12:5 - ANS100:5:1
Activated Sludge:
At what concentration level should dissolved oxygen be maintained during
the initial start up of a oxidation ditch? _____? - ANS2.0 mg/L
Activated Sludge:
Bacteria are in the ______kingdom - ANSMonera Kingdom
Activated Sludge:
1
,Following the activated sludge what process modification is very sensitive
to bulking?
a. conventional modification
b. extended aeration activate sludge
c. complex mix aeration
d. pure oxygen - ANSconventional modification
Activated Sludge:
Grease should be cleaned from walkaways with a stiff brush and
a. detergent
b. bleach
c. trisodium phosphate
d. phosphate-free surfactant - ANStrisodium phosphate
Activated Sludge:
How much of the solids should be wasted each week in the summer form a
package wastewater treatment plant for the best quality? - ANS5%
Activated Sludge:
If an activated sludge plant is hit with a high organic load, what will most
like occur in the aeration tank? - ANSsignificant decrease in DO
Activated Sludge:
2
,In a small package, wastewater treatment plant, the operator should try to
keep the dissolved oxygen in the aeration tank at approximately:____mg/L
- ANS2.0 mg/L
Activated Sludge:
Mixed liquor is a combination of what 3 things? - ANSactivated sludge in an
aeration tank
+
primary effluent
+
return sludge/raw wastewater
Activated Sludge:
Most algae are in the____kingdom - ANSProtista Kingdom
Activated Sludge:
Of the following, which is the least important nutrient in wastewater
treatment for microorganisms to reproduce?
a. potassium
b. nitrogen
c. carbon in organic matter
d. phosphorous - ANSpotassium
3
, Activated Sludge:
Primary treatment is not required in which modified activated sludge
process?
a. step aeration
b. complete mix aeration
c. tapered aeration
d. extended aeration activated sludge - ANSextended aeration activation
sludge
Activated Sludge:
What is the critical factor in any method to control the aeration tank?
a. BOD
b. F/M
c. COD
d. DO - ANSF/M ratio
Activated Sludge:
What is the most accurate measure of the organisms present in an aerator
for treating incoming wastes? - ANSMLVSS
Activated Sludge:
4
