Water Filter Pitchers (and Faucet Mounts)

Point-of-use (POU) granular activated carbon (GAC) water filter pitchers and faucet mounted filters are a popular, affordable solution for improving drinking water quality in homes. These filters, such as those from brands like Brita or PUR, use GAC to enhance taste and remove specific contaminants at the point of consumption, making them ideal for renters or small households.

What Are Activated Carbon Filters?

Water pitcher filters utilize what's called activated carbon—a highly porous material derived from sources like coconut shells, coal, or wood—to remove contaminants from water. The carbon is "activated" through a heating process that creates a vast network of microscopic pores, providing a large surface area (up to 1000 m²/g) for adsorption.

While these filters can also be found in point-of-entry whole home filters, they are most commonly found in the water pitcher filter or tap-mounted form.

How It works:

Activated carbon filters operate through adsorption, where contaminants bind to the carbon’s porous surface as water passes through. This process traps organic compounds, chlorine, and some heavy metals, improving water taste and safety. 

Unlike reverse osmosis (RO), which removes up to 99.99% of total dissolved solids (TDS) via a semi-permeable membrane, activated carbon filters do not significantly reduce dissolved inorganics or microorganisms, limiting their scope but simplifying maintenance and reducing waste.

Granular Activated Carbon (GAC) consists of loose carbon granules packed into a cartridge or bed, allowing water to flow through with minimal resistance.

Water passes through the granules, adsorbing contaminants onto their surfaces. The loose structure enables high flow rates but offers less contact time, reducing efficiency for some contaminants. The major benefits with a GAC filter is its accessibility and affordability -- often found as common household filter pitchers. However, GAC is less effective for heavy metals (e.g., lead, mercury) or complex contaminants compared to carbon block.

Contaminant Removal Capabilities

Activated carbon filters excel at removing organic compounds, chlorine, and some heavy metals but are less effective than RO for dissolved inorganics, microorganisms, and certain heavy metals. See a list of contaminants that activated charcoal systems can assist with:

Contaminant	Can Carbon Block Help?	Explanation
1,1 Dichloroethane	Yes	VOC, effectively removed by carbon block due to dense structure.
1,1 Dichloroethylene	Yes	VOC, certified under NSF/ANSI 53 for carbon block.
1,1 Dichloropropene	Yes	VOC, carbon block more effective due to longer contact time.
1,1,1 Trichloroethane	Yes	VOC, certified for carbon block.
1,1,1,2 Tetrachloroethane	Yes	VOC, carbon block outperforms GAC.
1,1,2 Trichloroethane	Yes	VOC, certified for carbon block.
1,1,2,2 Tetrachloroethane	Yes	VOC, effectively removed by carbon block.
1,2 Dichlorobenzene	Yes	VOC, certified under NSF/ANSI 53 for carbon block.
1,2 Dichloroethane	Yes	VOC, certified for carbon block.
1,2 Dichloropropane	Yes	VOC, certified for carbon block.
1,2,3 Trichlorobenzene	Yes	VOC, carbon block outperforms GAC.
1,2,3 Trichloropropane	Yes	VOC, carbon block more effective.
1,2,4 Trichlorobenzene	Yes	VOC, carbon block outperforms GAC.
1,2,4 Trimethylbenzene	Yes	VOC, carbon block more effective.
1,3 Dichlorobenzene	Yes	VOC, certified for carbon block.
1,3 Dichloropropane	Yes	VOC, carbon block more effective.
1,3 Dichloropropene	Yes	VOC, carbon block outperforms GAC.
1,3,5 Trimethylbenzene	Yes	VOC, carbon block more effective.
1,4 Dichlorobenzene	Yes	VOC, certified for carbon block.
2,2 Dichloropropane	Yes	VOC, carbon block more effective.
Aluminum	Partial	Carbon block may reduce some forms.
Antimony	Partial	Carbon block certified for some reduction.
Arsenic	Partial	Carbon block may reduce As(V).
Benzene	Yes	VOC, certified under NSF/ANSI 53 for carbon block.
Bromobenzene	Yes	VOC, carbon block outperforms GAC.
Bromochloromethane	Yes	VOC, carbon block more effective.
Bromodichloromethane	Yes	THM, certified for carbon block.
Bromoform	Yes	THM, certified for carbon block.
Bromomethane	Partial	Volatile gas, partial removal by carbon block.
Cadmium	Partial	Carbon block certified for some reduction.
Carbon Tetrachloride	Yes	VOC, certified for carbon block.
Chlorobenzene	Yes	VOC, certified for carbon block.
Chloroethane	Yes	VOC, carbon block more effective.
Chloroform	Yes	THM, certified for carbon block.
Chloromethane	Partial	Volatile gas, partial removal by carbon block.
Chlorotoluene 2	Yes	VOC, carbon block outperforms GAC.
Chlorotoluene 4	Yes	VOC, carbon block outperforms GAC.
Chromium (Total)	Partial	Carbon block certified for some Cr(VI) reduction.
cis 1,2 Dichloroethylene	Yes	VOC, certified for carbon block.
Copper	Partial	Carbon block certified for some reduction.
Dibromochloromethane	Yes	THM, certified for carbon block.
Dibromochloropropane	Yes	Pesticide, certified for carbon block.
Dibromomethane	Yes	VOC, carbon block more effective.
Dichlorodifluoromethane	Partial	Volatile gas, partial removal by carbon block.
Dichloromethane	Yes	VOC, certified for carbon block.
Ethylbenzene	Yes	VOC, certified for carbon block.
Ethylene dibromide	Yes	VOC, certified for carbon block.
Hexachlorobutadiene	Yes	VOC, carbon block outperforms GAC.
Hydrogen Sulfide (H2S) Gas Strip	Yes	Gas, effectively removed by carbon block.
Iron	Partial	Carbon block may reduce some forms.
Isopropylbenzene	Yes	VOC, carbon block more effective.
Lead	Partial	Carbon block certified under NSF/ANSI 53 for reduction.
m,p Xylene	Yes	VOC, certified for carbon block.
Manganese	Partial	Carbon block may reduce some forms.
Mercury	Partial	Carbon block certified for some reduction.
Methyl Tertiary Butyl Ether	Yes	VOC, certified for carbon block.
n Butylbenzene	Yes	VOC, carbon block more effective.
n Propylbenzene	Yes	VOC, carbon block more effective.
Naphthalene	Yes	VOC, carbon block outperforms GAC.
o Xylene	Yes	VOC, certified for carbon block.
p Isopropyltoluene	Yes	VOC, carbon block more effective.
sec Butylbenzene	Yes	VOC, carbon block more effective.
Silver	Partial	Carbon block may reduce some forms.
Styrene	Yes	VOC, certified for carbon block.
tert Butylbenzene	Yes	VOC, carbon block more effective.
Tetrachloroethylene	Yes	VOC, certified for carbon block.
Toluene Petroleum Compounds	Yes	VOC, certified for carbon block.
Total THMs	Yes	Disinfection byproducts, certified for carbon block.
trans 1,3 Dichloropropene	Yes	VOC, carbon block more effective.
Trichloroethylene	Yes	VOC, certified for carbon block.
Trichlorofluoromethane	Partial	Volatile gas, partial removal by carbon block.
Turbidity	Partial	Carbon block reduces fine particles (0.5–5 microns).
Vinyl Chloride	Yes	VOC, certified for carbon block.
Zinc	Partial	Carbon block certified for some reduction.