Question

Given below are two statements:
Statement I: In a scrubber, exhaust from the thermal plant is passed through the electric wires to charge the dust particles.
Statement II: Particular matter (PM 2.5) can not be removed by scrubber but can be removed by an electrostatic precipitator.
In the light of the above statements, choose the most appropriate answer from the options given below:

• A. Both statement I and Statement II are correct
• B. Both statement I and Statement II are incorrect
• C. Statement I is correct but statement II is incorrect
• D. Statement I is incorrect but statement II is correct

Answer 1

Answer: (B)

Both statement I and Statement II are incorrect

Answer 2

In an electrostatic precipitator:

• Electrode wires produce a corona that releases electrons.
• These electrons attach to dust particles and give them a net negative charge.
• Grounded collecting plates attract negatively charged dust particles.
• Thus dust particles are removed from air.
• A spray of water or lime is generated in the scrubber and exhaust is passed through this spray.
• Scrubber removes gases; like Sulphur dioxide from air.

Electrostatic precipitators are quite efficient in removing particulate matter from the air, but very small particulate matter (PM 2.5) cannot be removed by the precipitators.