How can electrostatic precipitators and scrubbers reduce pollution from coal-fired power plants?

Electrostatic precipitators and scrubbers are essential technologies for mitigating the environmental impact of coal-fired power plants by removing harmful pollutants from flue gas before it is released into the atmosphere.12

Electrostatic Precipitators

These devices are primarily used to control particulate matter, such as fly ash. As flue gas enters the unit, particles are given an electric charge via high-voltage discharge electrodes. These charged particles are then attracted to and trapped on oppositely charged, grounded collection plates. Periodically, the plates are mechanically "rapped" to dislodge the accumulated dust into a hopper for disposal. This process is highly efficient, capable of removing over 99 percent of particulate matter.312

Scrubbers

Scrubbers are primarily employed for flue gas desulfurization to remove sulfur dioxide.41
* Wet Scrubbers: Flue gases contact a liquid or slurry of alkaline sorbent (such as lime or limestone), which reacts with sulfur dioxide to trap it.41
* Dry Scrubbers: These use dry pulverized lime or limestone; the resulting solid particles are subsequently captured by filters.4

While primarily engineered for sulfur dioxide, scrubbers can also effectively remove mercury from flue gas.1