- 1(current)
Q. No.Which of the following in sewage treatment removes suspended solids?
1. Secondary treatment
2. Primary treatment
3. Sludge treatment
4. Tertiary treatment
A high value of BOD (Biochemical Oxygen Demand) indicates that:
| 1. | water is pure |
| 2. | water is highly polluted |
| 3. | water is less polluted |
| 4. | consumption of organic matter in the water is higher by the microbes |
What gases are produced in anaerobic sludge digesters?
1. Methane and CO2
2. Methane, Hydrogen Sulphide and CO2
3. Methane, Hydrogen Sulphide and CO
4. Hydrogen Sulphide and CO2
Measuring Biochemical Oxygen Demand (BOD) is a method used for:
| 1. | Estimating the amount of organic matter in sewage water |
| 2. | Working out the efficiency of oil-driven automobile engines |
| 3. | Measuring the activity of Saccharomyces cerevisiae in producing curd on a commercial scale |
| 4. | Working out the efficiency of RBCs about their capacity to carry oxygen |
Domestic sewage in large cities:
| 1. | is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plant (STPs) |
| 2. | when treated in STPs, does not require the aeration step as the sewage contains adequate oxygen |
| 3. | has very high amounts of suspended solids and dissolved salts |
| 4. | has a high BOD as it contains both aerobic and anaerobic bacteria |
Select the correct statement from the following:
| 1. | Biogas is produced by the activity of aerobic bacteria on animal waste |
| 2. | Methanobacterium is an aerobic bacterium found in the rumen of cattle |
| 3. | Biogas, commonly called gobar gas, is pure methane |
| 4. | Activated sludge-sediment in settlement tanks of sewage treatment plant is a rich source of aerobic bacteria |
What is B.O.D.:
1. The amount of utilized by organisms in the water
2. The amount of utilized by microorganisms for decomposition
3. The total amount of present in water
4. All of the above
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Q. No.
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