Chemical Engineering - Environmental Engineering

31.
The maximum permissible noise level to which a man working in a chemical plant can be exposed for eight hours per day is about __________ decibels.
60
90
105
120
Answer: Option
Explanation:
No answer description is available. Let's discuss.

32.
The most commonly used chemical coagulant in water treatment is
ferrous sulphate
alum
lime
hydrazine
Answer: Option
Explanation:
No answer description is available. Let's discuss.

33.
The biological decomposition of organic substances in wastes controlled conditions is called
incineration
biological oxidation
composting
none of these
Answer: Option
Explanation:
No answer description is available. Let's discuss.

34.
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
CO2
SO2
hydrocarbons
CFC (chloro fluoro carbon)
Answer: Option
Explanation:
No answer description is available. Let's discuss.

35.
Smog is not formed due to the presence of __________ in the atmosphere.
SO2
NOx
CO2
any of these
Answer: Option
Explanation:
No answer description is available. Let's discuss.