MCQOPTIONS
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MCQOPTIONS
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.
| 51. |
In which of the following process, the sludge is dried and disposed in land? |
| A. | Centrifugation |
| B. | Drying lagoon |
| C. | Drying bed |
| D. | Vacuum filter |
| Answer» D. Vacuum filter | |
| 52. |
The range of temperature at which mesophilic microorganism becomes active in sludge digester is ___________ |
| A. | 30-40°C |
| B. | 10-40°C |
| C. | 20-50°C |
| D. | 20-40°C |
| Answer» E. | |
| 53. |
Which of the following is called as a conventional trickling filter? |
| A. | Rapid sand filter |
| B. | Slow sand filter |
| C. | High rate trickling filter |
| D. | Low rate trickling filter |
| Answer» E. | |
| 54. |
Which of the following is not suitable for dewatering of raw sludge? |
| A. | Centrifugation |
| B. | Drying lagoon |
| C. | Drying bed |
| D. | Vacuum filter |
| Answer» C. Drying bed | |
| 55. |
The maximum depth of aeration tank used in activated sludge process is ___________ |
| A. | 1m |
| B. | 2m |
| C. | 4.5m |
| D. | 5.5m |
| Answer» D. 5.5m | |
| 56. |
The recirculation ratio for the low rate trickling filter is ___________ |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 0 |
| Answer» E. | |
| 57. |
Which of the following is correct regarding pH in different stages of the sludge digestion process? |
| A. | Acid fermentation > Acid regression > Alkaline fermentation |
| B. | Acid regression > Acid fermentation > Alkaline fermentation |
| C. | Acid fermentation < Acid regression < Alkaline fermentation |
| D. | Acid fermentation < Acid regression > Alkaline fermentation |
| Answer» D. Acid fermentation < Acid regression > Alkaline fermentation | |
| 58. |
The efficiency of a percolating filter is given by ___________ |
| A. | 100/(1+0.0044 (μ)) |
| B. | 100/(1+0.044 (μ)½) |
| C. | 100/(1+0.44 (μ)½) |
| D. | 100/(1+0.0044 (μ)½) |
| Answer» E. | |
| 59. |
Which of the following plant nutrient is not found in municipal sewage? |
| A. | Arsenic |
| B. | Phosphorous |
| C. | Potassium |
| D. | Nitrogen |
| Answer» B. Phosphorous | |
| 60. |
The maximum aeration period for a conventional activated sludge system is ___________ |
| A. | 2 hours |
| B. | 3 hours |
| C. | 4 hours |
| D. | 6 hours |
| Answer» E. | |
| 61. |
Which of the following is correct regarding anaerobic digestion in the sludge digestion process? |
| A. | It contains high amount of biomass |
| B. | It is a low energy process |
| C. | It causes infertility in soil |
| D. | Aerobic bacteria oxidize the organic matter |
| Answer» C. It causes infertility in soil | |
| 62. |
The high rate sludge digestion tanks are used when the capacity of the tank is ____ million liters per day. |
| A. | 1 |
| B. | 3 |
| C. | 4 |
| D. | 10 |
| Answer» D. 10 | |
| 63. |
Which of the following sludge process has maximum aeration period? |
| A. | Conventional process |
| B. | Extended process |
| C. | Step aeration process |
| D. | Tapered aeration |
| Answer» C. Step aeration process | |
| 64. |
The effective area of the diffuser plate used in the aeration tank is ___________ |
| A. | 400cm² |
| B. | 780cm² |
| C. | 1160cm² |
| D. | 800cm² |
| Answer» C. 1160cm² | |
| 65. |
With how much pressure the air is filled in the aeration tank? |
| A. | 70-90kN/m² |
| B. | 34-56kN/m² |
| C. | 10-20kN/m² |
| D. | 35-70kN/m² |
| Answer» E. | |
| 66. |
The effective area of tube diffuser used in the aeration tank is ___________ |
| A. | 400cm² |
| B. | 780cm² |
| C. | 1160cm² |
| D. | 800cm² |
| Answer» D. 800cm² | |
| 67. |
Which of the following filter is used in the anaerobic treatment of sewage? |
| A. | Intermittent sand |
| B. | Trickling filter |
| C. | Contact filter |
| D. | Biological filter |
| Answer» E. | |
| 68. |
Which of the following is the correct expression of the aeration period in hours? |
| A. | V/Q |
| B. | 24V/Q |
| C. | V/24Q |
| D. | Q/V |
| Answer» C. V/24Q | |
| 69. |
In which of the following method, the sludge is rotated for dewatering process? |
| A. | Centrifugation |
| B. | Drying lagoon |
| C. | Drying bed |
| D. | Vacuum filter |
| Answer» B. Drying lagoon | |
| 70. |
_________ is the time at which sewage is detained in the aeration tank. |
| A. | Average time |
| B. | Detention time |
| C. | Aeration period |
| D. | Reaeration period |
| Answer» D. Reaeration period | |
| 71. |
Which of the following is not a part of dewatering process? |
| A. | Drying bed |
| B. | Air flotation |
| C. | Vacuum filter |
| D. | Drying lagoon |
| Answer» C. Vacuum filter | |
| 72. |
Which of the following is incorrect about aerobic digestion in the sludge digestion process? |
| A. | It has a low capital cost |
| B. | It is easier to manage. |
| C. | It has high residual energy |
| D. | It decreases the BOD |
| Answer» D. It decreases the BOD | |
| 73. |
With which device, the air is introduced in the aeration tank? |
| A. | Diffuser plate |
| B. | Paddles |
| C. | Cone with spiral vanes |
| D. | Header pipe |
| Answer» B. Paddles | |
| 74. |
The detention period of the Sheffield mechanical aeration tank is ___________ |
| A. | 15 hours |
| B. | 1minute |
| C. | 1 hour |
| D. | 4 hours |
| Answer» B. 1minute | |
| 75. |
Which of the following process is not involved in sludge thickening? |
| A. | Gravity thickening |
| B. | Vacuum filter |
| C. | Air flotation |
| D. | Centrifugation |
| Answer» C. Air flotation | |
| 76. |
7% of solids concentration of thickened sludge is obtained from gravity thickener. What is the type of sludge? |
| A. | Primary sludge |
| B. | Secondary sludge |
| C. | Tertiary sludge |
| D. | Activated sludge |
| Answer» E. | |
| 77. |
Which of the following is obtained in the secondary tank in two stage sludge digester? |
| A. | Partially digested sludge |
| B. | Partially digested sludge and supernatant liquor |
| C. | Digested sludge and supernatant liquor |
| D. | supernatant liquor |
| Answer» D. supernatant liquor | |
| 78. |
The device used for the aeration in the combined aerator is ___________ |
| A. | Header pipe |
| B. | Diffuser plate and paddles |
| C. | Cone with spiral vanes |
| D. | Diffuser plate |
| Answer» C. Cone with spiral vanes | |
| 79. |
The design value of food to microorganism ratio in the tapered aeration sludge process is ___________ |
| A. | 0.1 |
| B. | 0.2 |
| C. | 0.4 |
| D. | 0.8 |
| Answer» D. 0.8 | |
| 80. |
Which of the following is not used for drying of sludge? |
| A. | Multiple effect evaporation |
| B. | Dual effect evaporation |
| C. | Rotary dryer |
| D. | Spray dryer |
| Answer» C. Rotary dryer | |
| 81. |
The BOD of supernatant liquor in a sludge digestion process is ____ ppm. |
| A. | 3000 |
| B. | 0 |
| C. | 1000 |
| D. | 250 |
| Answer» B. 0 | |
| 82. |
Which gas is produced in aerobic digestion of sludge? |
| A. | NO₂ |
| B. | CO₂ |
| C. | O₂ |
| D. | H₂S |
| Answer» C. O₂ | |
| 83. |
The minimum detention period of combined aerator is ___________ |
| A. | 1 hour |
| B. | 2 hours |
| C. | 3 hours |
| D. | 4 hours |
| Answer» D. 4 hours | |
| 84. |
The organic loading in a trickling filter is measured in ___________ |
| A. | m³/day |
| B. | gm/m²/day |
| C. | Kg/hectare-meter/day |
| D. | Kg/hectare/day |
| Answer» D. Kg/hectare/day | |
| 85. |
The speed at which the bubbles are formed in the simplex aerator? |
| A. | 15rpm |
| B. | 20rpm |
| C. | 60rpm |
| D. | 30rpm |
| Answer» D. 30rpm | |
| 86. |
Dorroco aerator is a type of ___________ |
| A. | Combined aerator |
| B. | Mechanical aerator |
| C. | Ridge and furrow type aerator |
| D. | Spiral flow type aerator |
| Answer» B. Mechanical aerator | |
| 87. |
Simplex aerator is a type of ___________ |
| A. | Combined aerator |
| B. | Mechanical aerator |
| C. | Ridge and furrow type aerator |
| D. | Spiral flow type aerator |
| Answer» C. Ridge and furrow type aerator | |
| 88. |
The hydrogen sulfide gas formed during the filtration of sewage can be removed by ___________ |
| A. | Carbonation |
| B. | Chlorination |
| C. | Addition of lime |
| D. | Titration with potassium dichromate |
| Answer» C. Addition of lime | |
| 89. |
The recirculation factor in a low rate trickling filter is ___________ |
| A. | 0 |
| B. | 1 |
| C. | 10 |
| D. | 100 |
| Answer» C. 10 | |
| 90. |
The maximum removal of suspended and dissolved impurities from the sewage is? |
| A. | 65 |
| B. | 70 |
| C. | 92 |
| D. | 99 |
| Answer» D. 99 | |
| 91. |
The color of the secondary sludge produced from the high rate trickling filter is ___________ |
| A. | Gray |
| B. | Black |
| C. | Brown |
| D. | Green |
| Answer» D. Green | |
| 92. |
Which of the following process is not involved in the treatment of sludge? |
| A. | Dewatering |
| B. | Drying |
| C. | Flocculation |
| D. | Conditioning |
| Answer» D. Conditioning | |
| 93. |
The range of organic loading in kg/hectare metre/ day in a high rate trickling filter is ___________ |
| A. | 6000-18000 |
| B. | 10000-20000 |
| C. | 5000-10000 |
| D. | 900-2200 |
| Answer» B. 10000-20000 | |
| 94. |
Which of the following is the final stage in the sludge treatment process? |
| A. | Digestion |
| B. | Dewatering |
| C. | Drying |
| D. | Thickening |
| Answer» D. Thickening | |
| 95. |
In which sludge treatment process, the organic solids are converted into more stable form? |
| A. | Dewatering |
| B. | Thickening |
| C. | Digestion |
| D. | Conditioning |
| Answer» D. Conditioning | |
| 96. |
The sludge treatment process to increase the solid content of sludge is ___________ |
| A. | Dewatering |
| B. | Thickening |
| C. | Conditioning |
| D. | Drying |
| Answer» C. Conditioning | |
| 97. |
The process of removal of water from the sludge is called ______ |
| A. | Dewatering |
| B. | Thickening |
| C. | Digestion |
| D. | Drying |
| Answer» B. Thickening | |
| 98. |
Recirculation increases the efficiency of high rate trickling filters. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 99. |
_______ is the ratio of volume of recirculated sewage to the raw sewage. |
| A. | Recirculation factor |
| B. | Recirculation ratio |
| C. | Food to mass ratio |
| D. | BOD |
| Answer» C. Food to mass ratio | |
| 100. |
The expression of the recirculation factor F is given by ___________ |
| A. | F = 1 / (1+0.1 (R/I))² |
| B. | F = (1+ R) / (1+0.1 (R/I))² |
| C. | F = (1+ I/R) / (1+0.1(R/I))² |
| D. | F = (1+ R/I) / (1+0.1(R/I))² |
| Answer» E. | |