In a coal fired power plant electrostatic precipitators are installed to control emission of:-
- SPM
- SO2
- CO
- NOx
Answer
(1) SPM
Solution
As per NCERT, the electrostatic precipitator is the most widely used device for removing particulate matter from the exhaust of thermal power plants.
⇒ Electrodes at several thousand volts produce a corona that releases electrons; these attach to dust particles and give them a negative charge.
⇒ The charged particles are attracted to the earthed collecting plates and removed; the precipitator can remove over 99% of particulate matter.
∵ Gases like SO2, CO and NOx are not particles, they are not removed by it (scrubbers / catalytic converters are used for them).
∴ Electrostatic precipitators control the emission of SPM (suspended particulate matter).
Answer: (1)