Learn More: Carbon Filtration
Modern technology has provided much of the developed world access to safe, treated drinking water. But the treatment process itself can affect munipal water's taste and smell.
One of the most common solutions for home treatment of municipal water is using carbon filters.
Carbon is a naturally absorptive material that can improve the taste and smell of drinking water. It can also help reduce the amount of treatment-related chemicals and other contaminants in your water supply.
How does chlorine affect water?
The primary substance used in municipal water treatment is chlorine. A widely used oxidizing agent with powerful disinfecting and bleaching properties, chlorine is added to drinking water to kill harmful bacteria and viruses.
However, continued exposure to high levels of chlorine can raise health concerns. Chlorine is a very potent chemical that strips hair and skin of its natural oils, causing dry skin, damaged hair, and brittle nails.
In addition, according to the U.S. Council of Environmental Quality, the risk of cancer for people who consume chlorinated water is 93% higher than for those whose water does not include chlorine.
Water filters that contain activated carbon will help reduce the effects of chlorine.
What is carbon and why is it used in water filters?
Carbon is a highly porous substance that collects and bonds organic chemicals to itself through adsorption. Because carbon is so porous, it has a large surface area to attract chemicals and contaminants.
The carbon used in water filters is typically from one of three sources: bituminous coal, wood-based media, or coconut shell media.
How do carbon filters work?
When water flows through a carbon filter, chemicals adhere to the carbon, leaving clean water. The flow rate and water temperature of the water help determine the effectiveness of this process.
Carbon can treat multiple toxic chemicals including VOCs (Volatile Organic Compounds) such as Benzene, Toluene, and some chlorinated compounds.
Carbon filters are also able to treat odors and discoloration.
However, carbon filters struggle to reduce inorganic contaminants (e.g. arsenic, nitrates) and other heavy metals. These inorganic contaminants typically require more robust filtration solutions such as reverse osmosis systems or specially designed filters.
An important difference: reduce vs remove
Very few if any water treatment or water purification systems can completely remove all possible water contaminants that may be active in a water supply.
Reduction of contaminants to safe levels is the primary focus of domestic water filtration systems. People can safely drink water with low levels of chemical contaminants.
The EPA mandates treated water may have a detectable level of chlorine up to 4 parts per million.
The two kinds of carbon filters
There are two primary types of carbon filters: Carbon blocks and Granular Activated Carbon (GAC) filters.
Carbon Block Filters: Carbon block filters are made by grinding activated carbon into a fine powder.
Carbon block filters have a larger surface area than GAC filters, which enables them to filter out a higher percentage of treated water. They are also more effective at filtering out particles, heavy metals and other contaminants.
However, carbon Block filters may need replacement sooner than GAC filters, as they entrap more particulates and absorb more chemicals.
GAC Filters: GAC filters are created using carbon that has been ground up and is loosely held together inside a cartridge.
GAC filters have a higher flow rate than carbon block filters as they are less restrictive.
How can I maintain my water quality with carbon filters?
It is important that filters are replaced on a regular schedule.
Every filter has a specific gallon rating to help a user estimate when the filter should be changed. When in doubt, filters should be changed every 6 months to ensure they are working at full removal capacity.
What carbon filter should I choose?
To treat the chlorine smell in the water you drink, cook, or shower with, install a carbon filter at the tap, dispenser, or shower head.
Point of use options include:
- Faucet Filter
- Water Pitcher Filter
- Countertop Filter
- Undersink Filter
- Reverse Osmosis Undersink System
- Refrigerator Filter
- Shower Filter
You could also install a replaceable cartridge filter at the point of entry to your home.
If you want to go beyond removing the taste and odor of chlorine to actually reducing it in your water supply, a whole home carbon tank system can treat the water for every tap in your home. You can choose from either a low maintenance carbon tank system, or a more robust backwashing carbon filter system.