Activated Carbon Filtration
A water treatment method using porous carbon material to adsorb contaminants, effective for removing chlorine, many organic chemicals, some PFAS, and improving taste and odor.
How It Works
Activated carbon filtration works by adsorption: contaminants stick to the enormous surface area of the carbon (1 gram of activated carbon has the surface area of a tennis court). Granular activated carbon (GAC) filters are used at the treatment plant level for removing PFAS, volatile organic compounds (VOCs), pesticides, and disinfection byproduct precursors. Point-of-use carbon filters (Brita, PUR, refrigerator filters) are effective for chlorine taste/odor, some lead, and certain organic contaminants but have limited effectiveness against PFAS, nitrate, fluoride, and most heavy metals. Carbon filters must be replaced regularly, a saturated filter stops working and can even release previously captured contaminants.
Related Terms
- PFAS (Forever Chemicals), Per- and polyfluoroalkyl substances, a class of thousands of synthetic chemicals that don't break down in the environment, accumulate in the human body, and are linked to cancer, immune disorders, and developmental problems.
- Reverse Osmosis (RO), A water treatment process that forces water through a semipermeable membrane to remove up to 99% of contaminants, including lead, PFAS, nitrate, arsenic, and most other dissolved substances.
- Chlorination, The most common method of disinfecting drinking water, adding chlorine or chloramine to kill bacteria, viruses, and parasites before water reaches your tap.
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About This Definition
This definition is part of the IsWaterSafe Drinking Water Safety Glossary, 22 terms explaining water contaminants, treatment methods, and safety standards. Written for homeowners, renters, journalists, and public health professionals.