Vapors and odors frequently form from a large part of atmospheric air contaminants. Most odors are gases, and filters (even electrostatic ones) will not remove them.
Some odors can be removed by cooling the gases to their condensation or freezing temperature. Some are removed by oxidation (and by ultraviolet ray treatment).
Others can be removed by combining them with other chemicals. They may be diluted with air, or absorbed into a liquid. They may also be absorbed into a solid.
Both vapors and odors can be removed with activated charcoal. Activated alumina with potassium permanganate is also used.