Activated carbon filtration for odor control works primarily through what mechanism?

• A. Adsorption of odor-causing compounds
• B. Oxidation of organics
• C. Biological degradation
• D. Filtration-only physical removal

Answer: (D)

Activated carbon filtration for odor control relies on adsorption—the odor molecules are drawn to and held on the carbon’s enormous internal surface area and within its porous structure. As air or water passes through, these volatile compounds bind to the carbon surfaces and become trapped in the pores, reducing odor intensity. This capacity depends on how much surface area the carbon has and how saturated it becomes over time, after which regeneration or replacement is needed.

Oxidation can alter or break down some organics, but it isn’t the primary mechanism in standard activated carbon filters. Biological degradation requires microbes and is typical of biofilters rather than plain activated carbon systems. Pure physical filtration removes particles, not dissolved odor-causing gases, so it doesn’t mainly drive odor removal in this setup.