ENVIRONMENTAL POLLUTION & CONTROL MCQS 23

ENVIRONMENTAL POLLUTION & CONTROL  MCQS 23

1. Limestone powder is injected during pulverised coal burning in boilers to __________ the flue gases.
(A) Reduce SO2 content in
(B) Catalytically convert SO2 to SO3 in
(C) Increase the dew point of
(D) None of these
Answer: Option A

2. Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in
(A) Coagulation and flocculation of colloids
(B) Oxidation of carbonaceous matter to CO2
(C) Nitrification or oxidation of ammonia derived from breakdown of nitrogenous organic matter to the nitrite and eventually to the nitrate
(D) All (A), (B) and (C)
Answer: Option D

3. Bag filter design is predominantly dependent on gas temperature, as it affects the gas density & viscosity and the selection of filtering material. The pressure drop in a bag filter is
(A) Inversely proportional to viscosity of gas
(B) Proportional to the viscosity & density of the gas
(C) Proportional to the pressure of the gas
(D) Both (B) and (C)
Answer: Option D

4. Presence of a certain minimum quantity of fluorine is desirable in potable water to prevent
(A) Dental cavities
(B) Scale formation
(C) Water-borne disease
(D) Corrosion
Answer: Option A

5. Presence of __________ hardness is responsible for the temporary hardness in water.
(A) Carbonate
(B) Calcium
(C) Chloride
(D) Sulphate
Answer: Option B

6. Pick out the wrong statement.
(A) Caustic embrittlement of boiler's metallic parts is caused by high concentration of caustic soda in boiler feed water
(B) Cooling and freezing of water kills the bacteria present in it
(C) With increasing boiler operating pressure of steam, the maximum allowable concentration of silica in feed water goes on decreasing
(D) Dissolved oxygen content in high pressure boiler feed water should be nil
Answer: Option B
7. The type of bacteria which is active in trickling filter during biological treatment of sewage is the __________ bacteria.
(A) Anaerobic
(B) Saprophytic
(C) Aerobic
(D) Parasitic
Answer: Option C

8. Foul odour and bad taste of water is removed by treating with
(A) Alum
(B) Bleaching powder
(C) Activated carbon
(D) Copper sulphate
Answer: Option C

9. Particulates (< 1μm size) remaining suspended in air indefinitely and transported by wind currents are called
(A) Fumes
(B) Mists
(C) Smoke
(D) Aerosols
Answer: Option D

10. World environment day is observed every year on the 5th of
(A) June
(B) December
(C) July
(D) September
Answer: Option A