WEF Industrial Wastewater Treatment
Certification Practice Exam Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. The primary objective of industrial wastewater treatment is to
A. Increase water hardness
B. Recover drinking water
C. Remove contaminants to meet discharge or reuse
requirements
D. Eliminate all dissolved gases
Answer: C
Industrial wastewater treatment focuses on reducing pollutants so
effluent meets regulatory or reuse standards.
2. Which parameter is most commonly used to measure organic
strength of industrial wastewater?
A. TSS
B. pH
C. BOD
D. Alkalinity
Answer: C
Biochemical Oxygen Demand (BOD) indicates the biodegradable
organic load.
3. Chemical Oxygen Demand (COD) differs from BOD because COD
A. Measures only biodegradable organics
B. Measures total oxidizable matter
, C. Requires biological incubation
D. Is not used in industry
Answer: B
COD measures both biodegradable and non-biodegradable
oxidizable compounds.
4. Which industry typically produces high-strength wastewater with
elevated fats, oils, and grease (FOG)?
A. Electronics manufacturing
B. Food processing
C. Textile dyeing
D. Metal plating
Answer: B
Food processing wastewater commonly contains high FOG and
organic content.
5. Equalization basins are used to
A. Increase wastewater temperature
B. Neutralize pathogens
C. Balance flow and pollutant loading
D. Remove dissolved oxygen
Answer: C
Equalization reduces hydraulic and organic shock loads to
downstream processes.
6. The main purpose of pH adjustment in industrial wastewater
treatment is to
A. Improve color
B. Protect treatment processes and equipment
C. Increase conductivity
D. Reduce turbidity
Answer: B
, Proper pH prevents corrosion, scaling, and biological process
inhibition.
7. Which chemical is commonly used to raise pH?
A. Sulfuric acid
B. Hydrochloric acid
C. Sodium hydroxide
D. Ferric chloride
Answer: C
Sodium hydroxide is a common alkaline chemical for pH
adjustment.
8. Primary treatment in industrial facilities typically involves
A. Biological oxidation
B. Chemical disinfection
C. Physical removal of solids
D. Nutrient polishing
Answer: C
Primary treatment focuses on removing settleable and floatable
solids.
9. Which unit process removes settleable solids by gravity?
A. Aeration basin
B. Clarifier
C. Trickling filter
D. Oxidation ditch
Answer: B
Clarifiers allow solids to settle under quiescent conditions.
10. Dissolved Air Flotation (DAF) is especially effective for
removing
A. Heavy metals
B. Settleable grit
Certification Practice Exam Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. The primary objective of industrial wastewater treatment is to
A. Increase water hardness
B. Recover drinking water
C. Remove contaminants to meet discharge or reuse
requirements
D. Eliminate all dissolved gases
Answer: C
Industrial wastewater treatment focuses on reducing pollutants so
effluent meets regulatory or reuse standards.
2. Which parameter is most commonly used to measure organic
strength of industrial wastewater?
A. TSS
B. pH
C. BOD
D. Alkalinity
Answer: C
Biochemical Oxygen Demand (BOD) indicates the biodegradable
organic load.
3. Chemical Oxygen Demand (COD) differs from BOD because COD
A. Measures only biodegradable organics
B. Measures total oxidizable matter
, C. Requires biological incubation
D. Is not used in industry
Answer: B
COD measures both biodegradable and non-biodegradable
oxidizable compounds.
4. Which industry typically produces high-strength wastewater with
elevated fats, oils, and grease (FOG)?
A. Electronics manufacturing
B. Food processing
C. Textile dyeing
D. Metal plating
Answer: B
Food processing wastewater commonly contains high FOG and
organic content.
5. Equalization basins are used to
A. Increase wastewater temperature
B. Neutralize pathogens
C. Balance flow and pollutant loading
D. Remove dissolved oxygen
Answer: C
Equalization reduces hydraulic and organic shock loads to
downstream processes.
6. The main purpose of pH adjustment in industrial wastewater
treatment is to
A. Improve color
B. Protect treatment processes and equipment
C. Increase conductivity
D. Reduce turbidity
Answer: B
, Proper pH prevents corrosion, scaling, and biological process
inhibition.
7. Which chemical is commonly used to raise pH?
A. Sulfuric acid
B. Hydrochloric acid
C. Sodium hydroxide
D. Ferric chloride
Answer: C
Sodium hydroxide is a common alkaline chemical for pH
adjustment.
8. Primary treatment in industrial facilities typically involves
A. Biological oxidation
B. Chemical disinfection
C. Physical removal of solids
D. Nutrient polishing
Answer: C
Primary treatment focuses on removing settleable and floatable
solids.
9. Which unit process removes settleable solids by gravity?
A. Aeration basin
B. Clarifier
C. Trickling filter
D. Oxidation ditch
Answer: B
Clarifiers allow solids to settle under quiescent conditions.
10. Dissolved Air Flotation (DAF) is especially effective for
removing
A. Heavy metals
B. Settleable grit
