Granulated Activated Carbon (GAC) is primarily used to remove which type of compounds?

• A. Dissolved inorganic minerals
• B. Pathogens
• C. Taste and odor compounds and some organics
• D. Heavy metals

Answer: (C)

Granulated activated carbon works by adsorption, pulling organic molecules onto its porous surface. This makes it especially effective at removing compounds that cause taste and odor, as well as certain organic contaminants like some VOCs and disinfection byproduct precursors. Dissolved inorganic minerals stay in solution and aren’t selectively attracted to carbon, so GAC doesn’t remove them reliably. Pathogens aren’t effectively eliminated by GAC alone—disinfection or filtration steps are needed for reliable pathogen removal. Heavy metals can sometimes be adsorbed, but GAC isn’t the primary or most reliable method for metal removal, so other treatment options like ion exchange or precipitation are typically used if metals are a concern.