ENVIRONMENTAL POLLUTION & CONTROL MCQS 19

ENVIRONMENTAL POLLUTION & CONTROL  MCQS 19

1. Which is the best and the most effective method for the removal of organic contaminant present in the polluted water in very small quantity (say < 200 mg/litre)?
(A) Lagooning
(B) Activated carbon adsorption
(C) Biological oxidation pond
(D) Chemical coagulation
Answer: Option B

2. Shouting by a man at his full voice corresponds to a voice level of about __________ decibels.
(A) 25
(B) 50
(C) 80
(D) 120
Answer: Option C

3. Which of the following pollutants, if present in atmosphere is detectable by its odour ?
(A) CO
(B) SO2
(C) NO2
(D) CO2
Answer: Option B

4. Which of the following dust collection equipments is the least efficient (for sub-micronic particles)?
(A) Dust catcher (gravity type)
(B) Cyclone separator
(C) Bag filter
(D) Hollow wet scrubber
Answer: Option A

5. Removal of __________ is accomplished by aeration of water.
(A) Dissolved gases
(B) Suspended solids
(C) Dissolved solids
(D) None of these
Answer: Option A

6. Which of the following is not a secondary air pollutant?
(A) Ozone
(B) Photochemical smog
(C) Sulphur dioxide
(D) All (A), (B) & (C)
Answer: Option C

7. Coal washing waste water containing about 3% suspended solids (comprising of clay, slate, stone etc.) is treated for solid particles removal
(A) By chemical coagulation
(B) In sedimentation tanks equipped with mechanical scrapper
(C) In vacuum filter
(D) In clarifiers
Answer: Option B

8. In water treatment, alum [Al2(SO4)3] is used for the process of
(A) Filtration
(B) Coagulation
(C) Sedimentation
(D) Disinfection
Answer: Option B

9. Particles having diameter greater than 75 μm (micrometer = 10-6 mm) are called
(A) Grit
(B) Dust
(C) Powder
(D) Smoke
Answer: Option A

10. Pick out the wrong statement
(A) The concentric atmosphere layer just above troposphere is called stratosphere, which is rich in ozone
(B) Mesosphere is characterised by very low atmospheric pressure and low temperature
(C) Troposphere is a dusty zone containing water vapor and clouds
(D) The radio waves used in the long distance radio communication are reflected back to earth by stratosphere
Answer: Option D