1. : What is the primary purpose of an Effluent Treatment System (ETS)?
(A) Energy production
(B) Pollution control
(C) Water desalination
(D) Increasing pH
2. : Which of the following is the first stage in most effluent treatment systems?
(A) Biological treatment
(B) Primary treatment
(C) Tertiary treatment
(D) Disinfection
3. : Which treatment process is mainly used to remove suspended solids from effluent?
(A) Sedimentation
(B) Filtration
(C) Reverse osmosis
(D) Chlorination
4. : What is the main function of biological treatment in effluent treatment systems?
(A) Removing oil and grease
(B) Killing pathogens
(C) Degrading organic matter
(D) Adjusting alkalinity
5. : Which microorganism group is primarily responsible for breaking down organic pollutants?
(A) Viruses
(B) Bacteria
(C) Algae
(D) Fungi
6. : Activated sludge process belongs to which type of treatment?
(A) Primary
(B) Secondary
(C) Tertiary
(D) Preliminary
7. : Which of the following is NOT removed during primary treatment?
(A) Large solids
(B) Grit
(C) Dissolved organic matter
(D) Floating materials
8. : What does COD stand for in effluent analysis?
(A) Chemical Oxygen Demand
(B) Carbon Oxide Deposition
(C) Calcium Oxide Dissolution
(D) Chlorine Oxidation Demand
9. : Which parameter indicates the amount of oxygen required by microorganisms to degrade organic matter?
(A) TDS
(B) BOD
(C) pH
(D) COD
10. : Trickling filter is used in which stage of effluent treatment?
(A) Primary
(B) Secondary
(C) Tertiary
(D) Disinfection
11. : Which of the following is a tertiary treatment method?
(A) Screening
(B) Sedimentation
(C) Activated sludge
(D) Filtration
12. : Which gas is commonly generated in anaerobic digestion of effluent sludge?
(A) Oxygen
(B) Methane
(C) Carbon monoxide
(D) Chlorine
13. : Which process is used for the disinfection of effluent water?
(A) Sedimentation
(B) Chlorination
(C) Filtration
(D) Coagulation
14. : Effluent treatment plants are mainly used in which sector?
(A) IT industry
(B) Textile industry
(C) Entertainment industry
(D) Banking sector
15. : What is the typical pH range for treated effluent before discharge?
(A) 2–4
(B) 5.5–9
(C) 10–12
(D) 1–3
16. : Which process removes oil and grease from industrial effluent?
(A) Screening
(B) Dissolved air flotation
(C) Chlorination
(D) Sedimentation
17. : Sludge from effluent treatment plants can be used for:
(A) Fertilizer
(B) Plastic production
(C) Textile dyeing
(D) Glass making
18. : Which type of treatment removes dissolved salts and heavy metals?
(A) Secondary treatment
(B) Preliminary treatment
(C) Tertiary treatment
(D) Primary treatment
19. : Which of the following is an advanced effluent treatment method?
(A) Reverse osmosis
(B) Screening
(C) Sedimentation
(D) Grit removal
20. : Which bacteria are mainly responsible for nitrification in effluent treatment?
(A) Escherichia coli
(B) Nitrosomonas and Nitrobacter
(C) Lactobacillus
(D) Bacillus subtilis
21. : What is the main disadvantage of activated sludge process?
(A) Low cost
(B) Small space requirement
(C) High sludge production
(D) Simple operation
22. : Effluent treatment helps industries to comply with:
(A) Financial standards
(B) Environmental regulations
(C) Tax laws
(D) Business ethics only
23. : Which of the following is removed by coagulation and flocculation?
(A) Dissolved salts
(B) Fine suspended solids
(C) Pathogens
(D) Methane gas
24. : What is the main purpose of a grit chamber in an effluent treatment system?
(A) Remove organic matter
(B) Remove pathogens
(C) Remove sand and heavy particles
(D) Remove dissolved salts
25. : Which of the following is a major challenge in effluent treatment systems?
(A) High efficiency
(B) Zero sludge production
(C) High energy consumption and cost
(D) Abundant land availability