Explore topic-wise MCQs in Bioprocess Engineering.

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