Q1: 1. Which unit operation is used to remove large debris and solids from domestic wastewater?

• A) Filtration
• B) Sedimentation
• C) Aeration
• D) Disinfection

Q2: 2. What is the purpose of aeration in wastewater treatment?

• A) To remove dissolved gases
• B) To provide oxygen for microbial growth
• C) To neutralize pH
• D) To remove suspended solids

Q3: 3. Which unit process involves the breakdown of organic matter by microorganisms in the absence of oxygen?

• A) Filtration
• B) Sedimentation
• C) Chlorination
• D) Anaerobic digestion

Q4: 4. What is the primary purpose of chlorination in wastewater treatment?

• A) To remove suspended solids
• B) To provide oxygen for microbial growth
• C) To disinfect the water
• D) To neutralize pH

Q5: 5. Which unit operation is used to separate dissolved solids from water by passing it through a membrane?

• A) Ultrafiltration
• B) Sedimentation
• C) Aeration
• D) Coagulation

Q6: 6. What is the purpose of coagulation in wastewater treatment?

• A) To provide oxygen for microbial growth
• B) To remove suspended solids
• C) To neutralize pH
• D) To clump together fine particles for easier removal

Q7: 7. Which unit process involves the addition of chemicals to neutralize acidic or alkaline wastewater?

• A) Neutralization
• B) Chlorination
• C) Aeration
• D) Filtration

Q8: 8. What is the purpose of a grit chamber in wastewater treatment?

• A) To remove dissolved gases
• B) To provide oxygen for microbial growth
• C) To trap sand, gravel, and other heavy particles
• D) To disinfect the water

Q9: 9. Which unit operation is used to disinfect wastewater by exposing it to ultraviolet (UV) light?

• A) Chlorination
• B) Filtration
• C) UV disinfection
• D) Sedimentation

Q10: 10. What is the primary purpose of primary treatment in wastewater treatment plants?

• A) To remove dissolved solids
• B) To disinfect the water
• C) To remove large debris and suspended solids
• D) To neutralize pH

Q11: 11. Which unit process involves the addition of alum or ferric chloride to wastewater to promote the formation of flocs for easier removal?

• A) Aeration
• B) Coagulation
• C) Neutralization
• D) Filtration

Q12: 12. What is the purpose of sludge dewatering in wastewater treatment?

• A) To remove dissolved gases
• B) To reduce the volume of sludge for disposal
• C) To neutralize pH
• D) To remove suspended solids

Q13: 13. Which unit operation is used to separate oil and grease from wastewater by skimming or using absorbent materials?

• A) Decantation
• B) Aeration
• C) Filtration
• D) Grease trap

Q14: 14. What is the primary function of secondary treatment in wastewater treatment plants?

• A) To remove large debris
• B) To disinfect the water
• C) To break down organic matter using microorganisms
• D) To adjust pH levels

Q15: 15. Which unit process involves the removal of nitrogen and phosphorus compounds from wastewater to prevent eutrophication in receiving water bodies?

• A) Nitrification
• B) Denitrification
• C) Phosphorus removal
• D) Biological filtration

Q16: 16. What is the purpose of final disinfection in wastewater treatment before discharge?

• A) To remove suspended solids
• B) To neutralize pH
• C) To disinfect the water
• D) To provide oxygen for microbial growth

Q17: 17. Which unit operation is used to remove fine suspended particles from wastewater by passing it through a porous medium?

• A) Coagulation
• B) Filtration
• C) Decantation
• D) Neutralization

Q18: 18. What is the purpose of settling tanks in wastewater treatment plants?

• A) To provide oxygen for microbial growth
• B) To remove dissolved gases
• C) To allow solids to settle at the bottom for removal
• D) To neutralize pH

Q19: 19. Which unit process involves the conversion of ammonia to nitrate and nitrite compounds in wastewater treatment?

• A) Nitrification
• B) Denitrification
• C) Aeration
• D) Sedimentation

Q20: 20. What is the purpose of grit removal in wastewater treatment?

• A) To remove dissolved solids
• B) To trap sand, gravel, and other heavy particles
• C) To disinfect the water
• D) To adjust pH levels

Q21: 21. Which unit operation is used to separate scum and floating materials from the surface of wastewater?

• A) Skimming
• B) Neutralization
• C) Aeration
• D) Chlorination

Q22: 22. What is the primary purpose of aerobic treatment processes in wastewater treatment plants?

• A) To remove dissolved gases
• B) To provide oxygen for microbial growth
• C) To neutralize pH
• D) To remove suspended solids

Q23: 23. Which unit process involves the removal of excess biological sludge to maintain system efficiency in wastewater treatment?

• A) Sludge digestion
• B) Sludge dewatering
• C) Sludge thickening
• D) Sludge drying

Q24: 24. What is the purpose of effluent disinfection in wastewater treatment plants?

• A) To remove suspended solids
• B) To neutralize pH
• C) To disinfect the water
• D) To provide oxygen for microbial growth

Q25: 25. Which unit operation is used to separate solid particles based on their settling velocities in wastewater treatment?

• A) Filtration
• B) Sedimentation
• C) Aeration
• D) Decantation