250+ TOP MCQs on Conventional Trickling Filter and Answers

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Environmental Engineering Multiple Choice Questions on “Conventional Trickling Filter”.

1. The breaking of the biomass from the slime layer in conventional filter is called _____
a) Sloughing
b) Carbonation
c) Biological magnification
d) Weathering
Answer: a
Clarification: The breaking of the biomass from the slime layer in conventional filter is called sloughing. It makes the effluent turbid.

2. 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: a
Clarification: The minimum hydraulic loading of percolating filter is 1m3/m2/day whereas, the maximum hydraulic loading of percolating filter is 4m3/m2/day.

3. 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: d
Clarification: Low rate trickling filter is called as a conventional trickling filter. It is also called a standard rate and percolating filter.

4. 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: b
Clarification: The BOD of the effluent obtained after the filtration of sewage from the low rate trickling filter is between 80 to 90% and the effluent obtained is highly nitrified and stabilized.

5. The efficiency of a percolating filter is given by ___________
a) 100/(1+0.0044 (μ))
b) 100/(1+0.044 (μ) 1/2)
c) 100/(1+0.44 (μ) 1/2)
d) 100/(1+0.0044 (μ) 1/2)
Answer: d
Clarification: The efficiency of a percolating filter is given by η = 100/(1+0.0044 (μ)1/2) where, μ is the organic loading in kg per hectare meter per day.

6. The removal of BOD is independent of the loading conditions in infiltration process.
a) True
b) False
Answer: b
Clarification: When the loading conditions are less, the efficiency of the filter will be more and the removal of BOD from the effluent will be more.

7. 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: b
Clarification: Efficiency of low rate trickling filter = 100/(1+0.0044 (μ)1/2) = 100/(1+0.0044 (900)1/2) = 100/1.132 = 88.3.

8. 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: c
Clarification: The organic loading in a trickling filter is measured in kg / hectare-meter/day where, 1 hectare = 104m3.

9. 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: b
Clarification: The hydrogen sulfide gas is formed when the fixed nozzles are used during the filtration process, so sewage is chlorinated to prevent the formation of H2S gas.

10. The recirculation factor in a low rate trickling filter is ___________
a) 0
b) 1
c) 10
d) 100
Answer: b
Clarification: The recirculation factor F = (1+ R/I) / (1+0.1 (R/I)) 2 = (1+0) /(1+0)2 = 1.

Global Education & Learning Series – Environmental Engineering .