ENVIRONMENTAL POLLUTION & CONTROL MCQS 11

ENVIRONMENTAL POLLUTION & CONTROL  MCQS 11

1. Which of the following is the most widely used disinfectant in water treatment?
(A) Chlorine
(B) Irradiation of water by ultraviolet light
(C) Cation exchanger
(D) Coagulation
Answer: Option A
2. Presence of nitrogen and phosphorous in waste water discharged into lakes and ponds causes
(A) Foaming
(B) Odour nuisances
(C) Undesirable plant growth
(D) Turbidity
Answer: Option C
3. There are five concentric layers within the atmosphere which is differentiated on the basis of temperature. The atmospheric layer which lies close to the earth's surface in which human being along with other organisms live is called troposphere. The rate at which air temperature in the troposphere gradually decreases with height is about __________ °C/km.
(A) 0.05
(B) 1
(C) 6.5
(D) 15
Answer: Option C
4. TLV of lead for public sewer/waste water is about __________ ppm.
(A) 1
(B) 25
(C) 150
(D) 650
Answer: Option A
5. Threshold limit value (TLV) of CO in air is __________ ppm.
(A) 5
(B) 50
(C) 2000
(D) 5000
Answer: Option B
6. Major sources of noise in furnace operation arises from air inspirators, combustion, side wall vibrations and fluctuation in the process heat load. A 50% increase in fuel firing rate may increase the furnace noise level by about __________ decibels.
(A) 3
(B) 30
(C) 7
(D) 70
Answer: Option A
7. Ethanolamine is an absorbent used for the removal of __________ from air/gas.
(A) HF
(B) SO2
(C) H2S
(D) Both (B) & (C)
Answer: Option D
8. Lagoons used for purification of polluted water
(A) Are large shallow artificial lakes also known as clarification lakes, maturation ponds or oxidation ponds
(B) Use micro-organisms/bacteria in presence of dissolved oxygen
(C) Gives an excellent final effluent (with 3 to 4 lagoons arranged in series) having suspended solid < 1 mg/litre and BOD = 3.8 mg/litre
(D) All (A), (B) & (C)
Answer: Option D
9. Which is the most efficient dust removal equipment for removal of submicronic dust particles from blast furnace gas?
(A) Packed scrubber
(B) Gravity settling chamber
(C) Electrostatic precipitator
(D) Hydrocyclone
Answer: Option C
10. 5-200 μm size particles are called
(A) Colloids or aerosols
(B) Powder
(C) Dust
(D) Smoke
Answer: Option A