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This section includes 122 Mcqs, each offering curated multiple-choice questions to sharpen your Bioprocess Engineering knowledge and support exam preparation. Choose a topic below to get started.
1. |
Which of the following do not comes under continuous filtration? |
A. | Vacuum rotary drum filter |
B. | Rubber belt filter |
C. | Belt filter cake discharge |
D. | Disc filter |
Answer» E. | |
2. |
What do you mean by the term ”Backwashing”? |
A. | Excluding intermittent use of compressed air during process |
B. | Is a form of destructive maintenance |
C. | Washing at the backside of the filter |
D. | Including intermittent use of compressed air during the process. |
Answer» E. | |
3. |
What type of filter does not come under the Membrane filters? |
A. | Ultra filtration |
B. | Microfiltration |
C. | Precoat (filter aid) filtration |
D. | filtrationd) Nanofiltration |
Answer» D. filtrationd) Nanofiltration | |
4. |
Microfiltration can be used to remove viruses. |
A. | True |
B. | False |
Answer» C. | |
5. |
A city is to install rapid sand filters downstream of the clarifiers. The design loading rate is selected to be 160 m3/ (m2.d). The design capacity of the water works is 0.35 m3/s. The maximum surface per filter is limited to 50 m2 and find out the normal filtration rate? |
A. | 154.3 m3/(m2.d) |
B. | 154.6 m3/(m2.d) |
C. | 155.6 m3/(m2.d)d) 155.3 m3/(m2. |
D. | . The design capacity of the water works is 0.35 m3/s. The maximum surface per filter is limited to 50 m2 and find out the normal filtration rate?a) 154.3 m3/(m2.d)b) 154.6 m3/(m2.d)c) 155.6 m3/(m2.d)d) 155.3 m3/(m2.d) |
Answer» B. 154.6 m3/(m2.d) | |
6. |
A rotary drum filter with 30% submergence is used to filter concentrated aqueous slurry of calcium carbonate containing 15lb of solids per cubic foot of water. The pressure–drop is 2011Hg. If the filter cake contains 50% mixture (wet basis), calculate the filter area required to filter 10 gal/min of slurry. The filter cycle time is 5 min. The specific cake resistance depends on the pressure–drop as:α (ft/lb) = α (Δp)0.26, where α = 2.90×1010Viscosity of the filtrate = 6.72×10-4 lb/ft-s. Density of calcium carbonate = 168.8 lb/ft3. Neglect filter medium resistance. |
A. | ≅ 88 ft2 |
B. | = α (Δp)0.26, where α = 2.90×1010Viscosity of the filtrate = 6.72×10-4 lb/ft-s. Density of calcium carbonate = 168.8 lb/ft3. Neglect filter medium resistance.a) ≅ 88 ft2b) ≅ 86 ft2 |
C. | ≅ 82 ft2 |
D. | ≅ 90 ft2 |
Answer» D. ≅ 90 ft2 | |
7. |
“Filter aid can also be added to the fermentation broth to increase the porosity of the cake as it forms”, what does this statement means? |
A. | To increase the pH of the fermentation broth |
B. | To decrease the filtration rate |
C. | To decrease the pI of the fermentation broth |
D. | To increase the filtration rate |
Answer» E. | |
8. |
Which of the following process is used to separate insoluble particles from liquids? |
A. | Filtration |
B. | Extraction |
C. | Drying |
D. | Sieving |
Answer» B. Extraction | |
9. |
What do you mean by filter cake? |
A. | The cake which is to be filtered |
B. | A porous membrane used to retain the solids |
C. | The solids which are present on the filter |
D. | A suspension to be filtered |
Answer» D. A suspension to be filtered | |
10. |
The slurry is ______________ |
A. | A suspension to be filtered |
B. | A porous membrane used to retain the solids |
C. | The solids which are present on the filter |
D. | A clear liquid passing through the filter |
Answer» B. A porous membrane used to retain the solids | |
11. |
In surface filtration, the size of particles retained is higher than the mean pore size of the medium. |
A. | True |
B. | False |
Answer» B. False | |
12. |
Filtration is a steady state. |
A. | True |
B. | False |
Answer» C. | |
13. |
Which of the following does not influence filtration? |
A. | Temperature |
B. | Density |
C. | Viscosity |
D. | pH |
Answer» E. | |
14. |
In which of the following the size of particles retained is much smaller than the pore size of the medium? |
A. | Batch filtration |
B. | Surface filtration |
C. | Submerged filtration |
D. | Depth filtration |
Answer» E. | |
15. |
Which of the following is not an advantage of PES membrane filters? |
A. | Low extractables |
B. | Fast flow |
C. | High protein binding |
D. | High throughput |
Answer» D. High throughput | |
16. |
The advantage of cellulose acetate filters is ________________ |
A. | Recovery of microorganisms |
B. | Low throughput |
C. | High protein binding |
D. | Low flow rates |
Answer» B. Low throughput | |
17. |
Which of the following filter is used in the filtration of bacteria? |
A. | Bottle top filters |
B. | Oxalate filters |
C. | Cellulose Acetate filters |
D. | PES membrane filters |
Answer» D. PES membrane filters | |
18. |
Which of the following filters are ideal for vitamin sterilization? |
A. | Bottle top filters |
B. | Cellulose Nitrate filters |
C. | Cellulose Acetate filters |
D. | PES membrane filters |
Answer» B. Cellulose Nitrate filters | |
19. |
Which of the following is not the application of filtration? |
A. | Sterilization of media |
B. | Removal of debris |
C. | Plasma clarification |
D. | Off-gas analysis |
Answer» E. | |
20. |
The pore size for the removal of viruses is _______________ |
A. | 20 nm |
B. | 30 nm |
C. | 25 nm |
D. | 35 nm |
Answer» B. 30 nm | |
21. |
What is the pore size of the filtration membrane to remove bacteria? |
A. | 0.25 µm |
B. | 0.22 µm |
C. | 0.27 µm |
D. | 0.26 µm |
Answer» C. 0.27 µm | |
22. |
In which of the following, both primary and secondary tanks are used? |
A. | Two stage sludge digesters |
B. | Single stage sludge digesters |
C. | Low rate digesters |
D. | High rate digesters |
Answer» B. Single stage sludge digesters | |
23. |
The minimum size of sludge digestion tank is ___________ |
A. | 0.5m |
B. | 1m |
C. | 2m |
D. | 3m |
Answer» E. | |
24. |
The maximum BOD removal efficiency of the Step aeration process of the activated sludge system is ___________ |
A. | 92% |
B. | 80% |
C. | 99% |
D. | 78% |
Answer» B. 80% | |
25. |
Which of the following activated sludge process has minimum food to microorganism ratio? |
A. | Extended aeration |
B. | Step aeration |
C. | Modified aeration |
D. | Conventional |
Answer» B. Step aeration | |
26. |
BOD of sewage is dependent on food to microorganism ratio. |
A. | True |
B. | False |
C. | May be True or False |
D. | Can't say |
Answer» B. False | |
27. |
The maximum temperature at which thermophilic microorganisms remain active in sludge digester is ___________ |
A. | 60°C |
B. | 40°C |
C. | 30°C |
D. | 20°C |
Answer» B. 40°C | |
28. |
_________ is defined as a volume in ml occupied by 1 gram of solid in the mixed liquor after 30 minutes of settling. |
A. | BOD loading |
B. | Suspended solid volume |
C. | Sludge volume index |
D. | Organic loading |
Answer» D. Organic loading | |
29. |
How many stages are there in the sludge digestion process? |
A. | 2 |
B. | 3 |
C. | 4 |
D. | 5 |
Answer» C. 4 | |
30. |
Which gas evolves the most in the sludge digestion process? |
A. | SO₂ |
B. | CO₂ |
C. | N₂ |
D. | CH₄ |
Answer» E. | |
31. |
The sludge digestion process is independent of which of the following? |
A. | Temperature of sludge |
B. | pH of sludge |
C. | Shape of tank |
D. | Mixing of sludge |
Answer» D. Mixing of sludge | |
32. |
Which of the following has minimum hydraulic retention time? |
A. | Conventional process |
B. | Extended process |
C. | Modified aeration process |
D. | Complete mix process |
Answer» D. Complete mix process | |
33. |
The design pressure of ____ is applied on pressure type flotation device. |
A. | 1kg/cm² |
B. | 2kg/cm² |
C. | 3kg/cm² |
D. | 6kg/cm² |
Answer» D. 6kg/cm² | |
34. |
The design Hydraulic loading rate of the gravity thickener is _______ m³/m²/day. |
A. | 20 |
B. | 39 |
C. | 40 |
D. | 85 |
Answer» B. 39 | |
35. |
In which sludge treatment process, the sludge is treated with chemicals? |
A. | Dewatering |
B. | Thickening |
C. | Conditioning |
D. | Drying |
Answer» D. Drying | |
36. |
The form of sludge which is free from pathogenic bacteria is ___________ |
A. | Undigested sludge |
B. | Digested sludge |
C. | Primary sludge |
D. | Supernatant liquor |
Answer» C. Primary sludge | |
37. |
The maximum size of filter media of a percolating filter is ___________ |
A. | 10mm |
B. | 25mm |
C. | 60mm |
D. | 75mm |
Answer» E. | |
38. |
Which of the following is not a drying bed? |
A. | Wedwire beds |
B. | Artificial media |
C. | Filter press |
D. | Conventional sand |
Answer» D. Conventional sand | |
39. |
The color of digestive sludge is ___________ |
A. | Blue |
B. | Black |
C. | Brown |
D. | Gray |
Answer» C. Brown | |
40. |
The BOD after the filtration of sewage from the low rate trickling filter is ___________ |
A. | 40-50% |
B. | 80-90% |
C. | 70-80% |
D. | 90-99% |
Answer» C. 70-80% | |
41. |
The removal of BOD is independent of the loading conditions in infiltration process. |
A. | True |
B. | False |
C. | May be True or False |
D. | Can't say |
Answer» C. May be True or False | |
42. |
The organic loading in low rate trickling filter is 900 kg/hectare-meter/day. What is the efficiency of the filter? |
A. | 43.1% |
B. | 88.3% |
C. | 7.04% |
D. | 83% |
Answer» C. 7.04% | |
43. |
Which of the following is called as air diffusion method? |
A. | Activated sludge aeration |
B. | Diffused air aeration |
C. | Mechanical aeration |
D. | Combined aeration |
Answer» C. Mechanical aeration | |
44. |
The maximum quantity of air required in diffused aerator is ______ m³ per million litres of sewage. |
A. | 4000 |
B. | 5000 |
C. | 6000 |
D. | 8000 |
Answer» E. | |
45. |
The breaking of the biomass from the slime layer in conventional filter is called _____ |
A. | Sloughing |
B. | Carbonation |
C. | Biological magnification |
D. | Weathering |
Answer» B. Carbonation | |
46. |
The design solid surface loading in an activated sludge process is ___________ |
A. | 10 kg/m²/day |
B. | 25 kg/m²/day |
C. | 15 kg/m²/day |
D. | 35 kg/m²/day |
Answer» C. 15 kg/m²/day | |
47. |
Which device is used in the aeration tank for cleaning purposes? |
A. | Diffuser plate |
B. | Paddles |
C. | Tube diffuser |
D. | Header pipe |
Answer» D. Header pipe | |
48. |
The organic loading in an activated sludge plant is defined as ___________ |
A. | Mass of BOD per day/Volume of the aeration tank |
B. | Volume of aeration tank/Mass of BOD per day |
C. | The mass of BOD per day/Volume of secondary clarifier |
D. | Aeration period * Volume of aeration tank |
Answer» B. Volume of aeration tank/Mass of BOD per day | |
49. |
The dewatered sludge cannot be disposed by ___________ |
A. | Composting |
B. | Heat drying |
C. | Acid fermentation |
D. | Incineration |
Answer» D. Incineration | |
50. |
The minimum hydraulic loading of percolating filter is ___________ |
A. | 1 m³/m²/day |
B. | 2 m³/m²/day |
C. | 3 m³/m²/day |
D. | 4 m³/m²/day |
Answer» B. 2 m³/m²/day | |