CO, SO₂ & H₂S
CO₂, NO & SO₃
CO₂, H₂S & NO₂
SO₃, NO₂ & CO₂
✅ The correct answer is option A.
Enviornmental Engineering MCQs
Fresh sewage is __________ in nature.
Acidic
Neutral
Alkaline
Highly acidic
✅ The correct answer is option C.
Inorganic impurities causing water pollution is
Fats
Carbohydrates
Salts of metals
Protein
✅ The correct answer is option C.
The main pollutant in waste water discharged from a petroleum refinery is oil (both in free and emulsified form). Free oil is removed by
Biological oxygen pond
Aerated lagoons
Trickling filters
Gravity separator having oil skimming devices
✅ The correct answer is option D.
TLV of ozone (O₃) and phosgene (COCl₂) in air is __________ ppm.
0.1
25
100
1000
✅ The correct answer is option A.
Which is the most efficient dust removal equipment for removal of sub-micronic dust particles from blast furnace gas?
Packed scrubber
Gravity settling chamber
Electrostatic precipitator
Hydrocyclone
✅ The correct answer is option C.
Tri-sodium phosphate is used in boiler water treatment to reduce
Turbidity
Caustic embrittlement
Suspended silica
Dissolved oxygen
✅ The correct answer is option B.
Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in
Coagulation and flocculation of colloids
Oxidation of carbonaceous matter to CO₂
Nitrification or oxidation of ammonia derived from breakdown of nitrogeneous organic matter to the nitrite and eventually to the nitrate
All of the above
✅ The correct answer is option D.
When the concentration of SO₂ in air is greater than __________ ppm, it gives a pungent smell.
0.01
0.1
1
4
✅ The correct answer is option D.
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.
Coal ash
Potassium cyanide
Ortho-xylene
None of these
✅ The correct answer is option B.