1. . Key issues for sampling of sewage is
(A) Accuracy
(B) Skill
(C) Cost
(D) All of these
2. . The crucial days for testing of BOD for sewage is
(A) None of these
(B) 2 Days
(C) 7 Days
(D) 5 Days
3. . Burning of fossil fuel causes increased
(A) Livestock
(B) Global Warming
(C) Waste
(D) Soil erosion
4. . The duty of Environmental Technologists is to protect and present
(A) Ideas of environmental conservation
(B) New invention and Techniques
(C) Environmental Problems
(D) Solution to weather control
5. . The study of Interrelationship between environment and animals
(A) Biology
(B) Ecology
(C) Sociology
(D) Taxonomy
6. . Important components of an ecosystem are
(A) Air, water and soil
(B) Energy, water, nitrogen and Soil minerals
(C) Carbon, hydrogen and nitrogen
(D) Buildings, roads and Schools
7. . Indiscriminate cutting or over harvesting of trees for timber or pulp, or to clear for agriculture, ranching, construction or other human activities
(A) Deforestation
(B) Desertification
(C) Cultivation
(D) Over population
8. . Pesticides are harmful to
(A) Land
(B) All of these
(C) Birds
(D) Animal
9. . Industrial wastewater or sewage when enters in a river, storm or sea is termed as
(A) Organic Pollution
(B) Non-point source of pollution
(C) Point source of pollution
(D) Inorganic Pollution
10. . Presence of Algae in water may cause
(A) Increase in carbon dioxide
(B) Increase PH value
(C) Increase in Oxygen
(D) Increase organic wastes
11. . Colour, taste, odour and temperature are
(A) Chemical parameters of water
(B) Physical parameters of water
(C) Biological parameters of water
(D) None of these
12. . Presence is a serious biological pollution indicator of water
(A) Dissolved minerals
(B) B-Collie
(C) Oxygen
(D) Carbon dioxide
13. . Settleable solids could be measured by using
(A) Jars
(B) Beakers
(C) Cylinders
(D) Imhoff cone
14. . The minimum limiting value of dissolved oxygen in stream water is
(A) 4.5 mg/l
(B) 6.5 mg/l
(C) 7.5 mg/l
(D) 8.5 mg/l
15. . Standard pH value for drinking water is
(A) 1 — 3
(B) 6.5 — 8.5
(C) 4.5 — 5.5
(D) 9 — 11
16. . Chemical coagulation is done by using chemicals
(A) Mineral acids & Cellulose
(B) Glycerin & fatty acids
(C) Carbon dioxide & nitric acid
(D) Ferrous sulphate & ferric chloride
17. . Disinfection of water is done by
(A) Sodium chloride
(B) Chlorine
(C) By air
(D) By activated sludge process
18. . Organic matters are regarded as
(A) Fats
(B) Carbohydrates
(C) Proteins
(D) All of these
19. . Turbidity in water is due to
(A) Solid Particles
(B) Excessive dissolved matters
(C) Gaseous materials
(D) High temperature
20. . Quantity of oxygen required for stabilization of the oxidizable organic matter present over 5 days of incubation at 20°C is called
(A) BOD
(B) DO
(C) COD
(D) TOC
21. . If the wastewater is biodegradable it is subjected to biodegradation usually of
(A) 16 Hours
(B) 24 Hours
(C) 48 Hours
(D) 32 Hours
22. . Bar screens provide the removal of
(A) Dissolved particles
(B) Odour
(C) Colour
(D) Floating solids, grit, grease and oil scums
23. . Grit removal devices rely on specific gravity between organic and inorganic solids to affect their representation
(A) Similarity
(B) Difference
(C) Filtration
(D) Sedimentation
24. . Method used for the removal of suspended solids, oil & grease from the wastewater
(A) Flotation
(B) Sedimentation
(C) Retention
(D) Chlorination
25. . Treatment often called clarification, sedimentation or settling
(A) Binary
(B) Secondary
(C) Tertiary
(D) Primary
26. . The bacteria which comes into action in the presence of free oxygen and light is called
(A) Pathogenic
(B) Anaerobic
(C) Aerobic
(D) Toxic
27. . Odour of the sewage is an indicator of
(A) Inorganic matters
(B) Organic matters
(C) Gaseous substances
(D) Dissolved substances
28. . Activated sludge contains water up to
(A) 40 — 50%
(B) 52 — 60%
(C) 70 — 82%
(D) 98 — 99%
29. . Sunlight may help in sewage
(A) Production of oxygen
(B) Killing of bacteria
(C) Production of bacteria
(D) Sewage disposal
30. . Filter media in trickling filter is generally of
(A) Crushed stone
(B) Concrete
(C) Wood
(D) Clay
31. . Chlorination of sewage may
(A) Decrease BOD
(B) Increase BOD
(C) Increase pollution
(D) Decrease head loss
32. . PH value for neutralization of domestic sewage is
(A) 6.8 — 7.2
(B) 5.5 — 6.5
(C) 4.5 — 5.5
(D) 7.2 — 8.2
33. . Thermophilic digestion is completed in
(A) 7 — 10 days
(B) 6 — 8 days
(C) 4 — 5 days
(D) 10 — 12 days
34. . Retaining period of water in septic tank / collection tank is known as
(A) Time period
(B) Decomposition period
(C) Digestion period
(D) Detention period
35. . Bacteria which digest organic and inorganic matter in a septic tank / collection tank is termed as
(A) Aerobic bacteria
(B) Anaerobic bacteria
(C) Facultative bacteria
(D) Thermophilic bacteria
36. . No treatment is necessary and raw sewage can directly be discharged into the volume of dilution water if dilution factor is
(A) Above 500
(B) 300 — 400
(C) 400 — 500
(D) 8 — 150
37. . Sewage should be completely treated before it is thrown into water for dilution if dilution factor is
(A) Less than 8
(B) 8 — 150
(C) 150 — 300
(D) Above 500
38. . Free board in a sewage tank is normally
(A) 20 cm
(B) 45 cm
(C) 40 cm
(D) 30 cm
39. . The most desirable way of sludge treatment is
(A) Dumping into sea
(B) Incineration
(C) Lagooning
(D) Heat drying
40. . Sprinkler irrigation is a method of applying sewage where
(A) Where there is water in excess
(B) On sandy and hilly areas
(C) For orchards & for tall plants
(D) In water logged areas
41. . Polluted gases are exhausted by
(A) Scum board
(B) Inlet
(C) Vent pipe
(D) Outlet
42. . Large particle collection in a sewage tank is termed as
(A) Settling tank
(B) Skimming tank
(C) Grit chamber
(D) Deterrence tank
43. . Free ammonia in the sewage is an indicator of
(A) Organic matters
(B) Nitrogenous matters
(C) Algae
(D) Inorganic matters
44. . Protein is a main component of
(A) Sugar
(B) Plants
(C) Fats
(D) Animal
45. . Contact bed is permitted to stay empty for a period of
(A) 10 hours
(B) 8 hours
(C) 6 hours
(D) 12 hours
46. . Intermittent sand filters are kept wet to keep the conditions
(A) Alive anaerobic bacteria
(B) Alive virus
(C) Alive aerobic bacteria
(D) Alive worms and insects
47. . Settling tank is used for
(A) Ozonation
(B) Secondary treatment
(C) Advanced oxidation treatment
(D) Primary treatment
48. . Colour, odour, temperature & turbidity test
(A) Biological tests
(B) Chemical tests
(C) Trace element tests
(D) Physical tests
49. . Consist of fixed screen and a moving cutter for reducing the size of waste particles
(A) Clarifier
(B) Grit Chamber
(C) Comminutors
(D) Flocculator
50. . Branches of biochemistry is
(A) Cellular
(B) Molecular
(C) All of these
(D) Metabolic