Operator Grade II Practice Exam

Tennessee Wastewater Treatment Operator Grade II Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary purpose of a wastewater treatment plant?
• Generate electricity
• Produce drinking water
• Remove pollutants from wastewater
• Increase water temperature

Rationale: The main function of a wastewater treatment plant is to

remove physical, chemical, and biological pollutants from sewage before it is discharged to the environment.

• Which of the following is a common primary treatment method?
• Activated sludge 1 / 4

• Sedimentation
• Trickling filter
• Chlorination

Rationale: Primary treatment typically involves physical processes like

sedimentation to remove settleable solids.

• Which unit process is used to remove nitrogen biologically?
• Sedimentation
• Activated sludge with nitrification/denitrification
• Coagulation
• Filtration

Rationale: Biological nitrogen removal uses nitrifying and denitrifying

bacteria in activated sludge or biofilm systems.

• What is the main function of a clarifier?
• Aerate wastewater
• Settle solids
• Disinfect water
• Remove odor

Rationale: Clarifiers allow suspended solids to settle, producing a clearer

effluent.

• Which parameter is used to measure organic strength in wastewater?
• pH
• Biochemical Oxygen Demand (BOD)
• Turbidity 2 / 4

• Temperature

Rationale: BOD measures the amount of oxygen required by

microorganisms to decompose organic matter in wastewater.

• What is the purpose of sludge digestion?
• Increase sludge volume
• Stabilize organic matter
• Remove nitrogen
• Increase pH

Rationale: Digestion reduces the organic content and odors in sludge,

making it safer for disposal.

• In wastewater treatment, what is TSS?
• Total Suspended Solids
• Total Soluble Solids
• Total Suspended Solids
• Total Salinity Standard

Rationale: TSS refers to solids that are suspended in water and can be

removed by settling or filtration.

• Which process uses microorganisms to remove organics from

wastewater?

• Coagulation
• Biological treatment
• Sedimentation
• Screening 3 / 4

Rationale: Biological treatment relies on bacteria and other

microorganisms to break down organic pollutants.

• What is the ideal pH range for activated sludge treatment?

A. 3-5

B. 5-6

C. 6.5-8.5

D. 9-10

Rationale: Activated sludge bacteria perform best in a near-neutral pH

range.

10. Chlorination is primarily used for:

• Disinfection
• Sedimentation
• Aeration
• Filtration

Rationale: Chlorination kills pathogens to ensure safe effluent discharge.

• What does NPDES stand for?
• National Pollution Data Environmental System
• National Pollutant Discharge Elimination System
• National Plant Design Environmental Standard
• None of the above

Rationale: NPDES is a permit system regulating pollutant discharge from

wastewater facilities.

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