Final answer:
Large industrial electrostatic precipitators remove over 99% of particulates from smoke stacks, while home precipitators can effectively remove airborne pollutants. Power plants also use scrubbers to clean various emissions, and technological advancements have made coal burning more efficient.
Step-by-step explanation:
To remove particulates from smoke stacks, large electrostatic precipitators are used in industrial settings. These systems are capable of eliminating over 99% of the particles from stack gas emissions that result from the combustion of coal and oil. Similarly, home precipitators are paired with heating and air conditioning systems to effectively cleanse the air of polluting particles, irritants, and allergens.
Power plants also employ scrubbers to cleanse emissions of sulfur dioxide (SO₂), nitrogen oxides (NOx), particulate matter, and mercury. Furthermore, innovations in technology and government-industry partnerships have led to more energy-efficient processes in coal utilization, reducing the amount of coal burned and consequently the emissions produced.
Electrostatic precipitators work by first applying a charge to particles in the airstream, and then attracting those charged particles to a filter. This principle is based on the work of American chemist Frederick Cottrell. In addition to industrial applications, colloidal particles, many of which are electrically charged in nature, can be removed using this method from a variety of mixtures, including smoke.