Environmental Engineering in Chemical Engineering MCQs

190. The density of the gases (present in air) decreases with increasing altitude to such an extent, that about 70% of the mass of atmospheric air is found in the lower 5 km. of the atmosphere. This lower region of atmosphere is called the

191. The average thickness of ozone layer in stratosphere is about __________ dobson unit (DU).

A. 20

192. Which of the following is the common pollutant emitted from metallurgical smelters, thermal power plant and cement plants?

C. SO₂

193. Lung cancer & DNA breakage are the major ill effects of excessive ozone exposure to human beings. Ozone layer depletion in the atmosphere is mainly caused by the presence of

A. CO₂

B. SO₂

C. Hydrocarbons

D. CFC (chloro fluoro carbon)

Discussion

194. Pick out the wrong statement.

A. Biological oxygen demand (BOD) is a characteristic and not a constituent of water

B. BOD is a measure of the amount of oxygen which will be demanded & used in 5 days by the biological decomposition of the organic matter present in water stream present as food for the living organi

C. BOD is expressed in mg/litre (typically, BOD=2.5 mg/litre for potable water)

D. None of these

Discussion

195. Water filtration rate in a slow sand filter ranges from __________ litres/m²/hr.

196. Thermal pollution of water increases its toxicity and oxidation of oxygen demanding waste besides favouring bacterial growth. A rise in water temperature by 10°C, doubles the toxic effects of __________ present in it.

Chemical Engineering Objective Questions { Environmental Engineering in Chemical Engineering }