The GATE Grind

GATE 2026 CE (CE2) – Question 27

Air Pollution and Municipal Solid Wastes · Air pollution: pollutants, sources, impacts, control and air quality index · 1 mark · Multiple choice

Column I presents common air pollutants, and column II presents treatment technologies commonly employed to control air pollutants.

Air pollutantTreatment technology
1 Dust (size 5–25 µm)P Cyclone separator
2 Carbon monoxide (CO)Q Wet lime-water scrubber
3 Sulfur dioxide (SO$_2$)R Electrostatic precipitator
4 Fly ash (size < 2.5 µm)S Catalytic converter

The option that CORRECTLY matches the air pollutant with its treatment technology is:

  1. 1 – P ; 2 – S ; 3 – Q ; 4 – R
  2. 1 – P ; 2 – R ; 3 – S ; 4 – Q
  3. 1 – R ; 2 – Q ; 3 – P ; 4 – S
  4. 1 – R ; 2 – Q ; 3 – S ; 4 – P

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Show answer and explanation

Correct answer: (A) 1 – P ; 2 – S ; 3 – Q ; 4 – R

Explanation

Cyclone separators remove coarse dust of 5 to 25 micrometres. A catalytic converter oxidises carbon monoxide. A wet lime-water scrubber removes sulfur dioxide, which dissolves and reacts with the lime. Very fine fly ash below 2.5 micrometres is collected in an electrostatic precipitator. That gives 1-P, 2-S, 3-Q and 4-R.