Iron
Zinc
Iodine
Bromine
✅ The correct answer is option A.
Enviornmental Engineering MCQs
Which of the following gases is having the widest explosion limit (about 2 to 81% gas in gas-air mixture), rendering it the property of the most explosive gas?
Hydrogen
Acetylene
Carbon monoxide
Ammonia
✅ The correct answer is option B.
Which of the following is an adsorbant used for the removal of SO₂ from gas/air?
Bog iron
Limestone powder or alkalised alumina
Silica gel
Active carbon
✅ The correct answer is option B.
Maximum allowable concentration of CO₂ in air for safe working is __________ ppm (parts per million).
50
1000
2000
5000
✅ The correct answer is option D.
Growth of __________ is promoted by the presence of manganese in water.
Files
Algae
Micro-organisms
Mosquitoes
✅ The correct answer is option C.
Disinfection of water is done to remove
Color
Bad taste
Foul odour
Bacteria
✅ The correct answer is option D.
Automobile exhaust is passed through two compartments catalytic converter employing platinum as catalyst for
Conversion of CO into CO₂ in the second compartment
Conversion of NOx into N₂ and NH₃ in the first compartment
Oxidation of unburnt hydrocarbon fuel in the second compartment
All of the above
✅ The correct answer is option D.
Which of the following is the most widely used disinfectant in water treatment?
Chlorine
Irradiation of water by ultraviolet light
Cation exchanger
Coagulation
✅ The correct answer is option A.
Coal washing waste water containing about 3% suspended solids (comprising of clay, slate, stone etc.) is treated for solid particles removal
By chemical coagulation
In sedimentation tanks equipped with mechanical scrapper
In vacuum filter
In clarifiers
✅ The correct answer is option B.
The ratio of oxygen available to the oxygen required for stabilisation of sewage is called the
Bacterial stability factor
Relative stability
Biological oxygen demand (BOD)
Oxygen ion concentration
✅ The correct answer is option B.