Mufflers (silencers)
Accoustical absorbent
Lagging of noisy duct
None of these
✅ The correct answer is option A.
Enviornmental Engineering MCQs
Dose of chlorine for disinfection of water is about __________ mg/litre of water.
0.01
0.1
0.3
1
✅ The correct answer is option D.
Which of the following is the most lethal water pollutant?
Phenol and cynide
Chlorine
Alkalis
Suspended solids
✅ The correct answer is option A.
Coal mines drainage waste water (acidic in nature) results from the earth’s water percolating through the voids created in coal bed during mining. This polluted water which either drains out naturally to water courses or are removed before starting the mining is
Neutralised by alkali treatment
Left as such without any treatment
Diluted with fresh water to reduce its acidity
None of these
✅ The correct answer is option A.
Ethanolamine is an absorbant used for the removal of __________ from air/gas.
HF
SO₂
H₂S
Both B & C
✅ The correct answer is option D.
Noise pollution level in a chemical plant is expressed in
Roentgen
Decibel
Hertz
None of these
✅ The correct answer is option B.
The upper layer of atmosphere is called the
Stratosphere
Troposphere
Ionosphere
None of these
✅ The correct answer is option A.
Algae growth in water is controlled by
Deoxidation
Chlorination
Bleaching
Aeration
✅ The correct answer is option B.
There are thirteen metals which are treated as pollutants. Which of the following metals is not a pollutant?
Mercury
Arsenic
Aluminium
Lead
✅ The correct answer is option C.