Are you looking for a way to remove chlorine and chloramine from your drinking water?
Chlorine and chloramine give your water a chemical taste and odor. They can also cause skin and eye irritation. A carbon filter is a good way to remove these chemicals from your water.
Conventional activated carbon can remove 95% of chlorine and approximately 50% of chloramine from water. Coconut shell activated carbon performs slightly better and can remove up to 75 to 90% of chloramine. Catalytic activated carbon is extremely effective – it can remove 99.9% of chlorine and chloramine from drinking water.
There are many different types of carbon filters available, so it’s important to choose the one that is right for your needs. Some filters are better at removing chlorine, while others are better at removing chloramine.
In this blog post, we will discuss how carbon filters work and how you can find the best type to remove chlorine and chloramine from your water.
How Does a Carbon Filter Work
A carbon filter contains activated carbon, which is made of charcoal. The charcoal is porous, which means it has a lot of tiny holes in it. These tiny holes are what makes the activated carbon so effective at removing chemicals from water. They have an incredible amount of surface area – this is what creates the attraction force that draws the chemicals into the carbon filter.
When water passes through the filter, the pores in the activated carbon particles grab onto the chlorine and chloramine molecules. It then removes them from the water. This process is known as adsorption.
Chlorine and chloramine are disinfectants added to municipal drinking water to kill bacteria and viruses in the water supply. Both of these chemicals can be removed from drinking water using an activated carbon filter.
Read my carbon design guide for more information.
Does Activated Carbon Remove Chlorine
Carbon filters are excellent at removing chlorine and other disinfection by-products like trihalomethanes from water. Activated carbon also removes bad tastes and odors, so you will be able to drink great-tasting water without any of the harmful chemicals.
Chlorine does not adsorb (stick) to activated carbon. Instead, the chlorine reacts with the carbon particle and is converted into a chloride ion. The chloride ion passes through the carbon bed and flows out to your water system.
Chloride ions are harmless and do not impart any bad taste or odors to your water.
How much chlorine can carbon remove?
Carbon filters are very effective at removing chlorine from drinking water. Most activated carbons achieve a minimum of 95% chlorine removal. High quality activated carbon can remove 99.9%+ of the chlorine in your water.
Because the chlorine removal process does not occur through adsorption, activated carbon has a very high capacity to remove chlorine. This means that the carbon in your filter will have a very long service life – some carbon can last a year or longer.
Does Activated Carbon Remove Chloramine
Carbon filters are not as effective at removing chloramine from water as they are at removing chlorine. If you are looking for a filter that will remove chloramine, you need one that is specifically designed for the task. Catalytic carbon filters are ideal at removing chloramine from your drinking water.
How much chloramine can carbon remove?
Chloramine is removed from water through a catalytic process. As water passes through the filter, the chloramine is decomposed into nitrogen gas, ammonia gas, and chloride ions. The nitrogen and ammonia gases are released into the atmosphere, while the chloride ions pass through the carbon bed and flow out to your water system.
Conventional activated carbon can remove up to 50% of chloramine from water. This means that a catalytic carbon filter is necessary for complete removal of chloramine from drinking water.
Type of Carbon versus Chlorine and Chloramine Removal
There are several different types of activated carbon. Each one has its own unique properties. Some are better at removing chlorine, while others are more effective at removing chloramine and other chemicals.
Coconut shell activated carbon
Activated carbon made from coconut shells is a popular choice for chlorine removal. It has high levels of activated carbon, and the pores are very small, which makes it ideal for removing small molecules like chlorine from water.
Coconut shell carbon performs reasonably well removing chloramine. As much as 75 to 90% of the chloramine can be removed.
Read my comprehensive article on coconut shell activated carbon.
Coal-based activated carbon
Most carbon is made from bituminous coal. This type of coal is high in activated carbon and has large pores, making it ideal for removing larger molecules like chloramine from water.
Coal-based activated carbon can remove up to 95% of the chlorine from water. This makes it a good choice for filters that are used to treat municipal drinking water. This type of carbon does not perform as well with chloramine – it typically can remove 50% of this disinfectant.
Catalytic activated carbon
Catalytic activated carbon is the ideal choice for removing chlorine and chloramine from water. It is activated carbon that has a specially activated surface to catalyze the breakdown chlorine and chloramine into their component parts.
Catalytic activated carbon can remove up to 99% of both chlorine and chloramine from water. This makes it ideal for applications where high levels of either disinfectant is present in the drinking water.
Because the removal process is a catalytic reaction rather than adsorption, there are no capacity issues with this type of filter media
What Type of Carbon Filter to Use for Chlorine and Chloramine
Carbon filters can be installed in a variety of locations to address chlorine and chloramine in your drinking water. They can be configured as:
point-of-entry – This type of filter is installed at the water entrance to your home. It will remove chlorine and chloramine from all of the water that enters your house, including water used for drinking, bathing, and washing.
point-of-use – This type of filter is installed on the faucet or under the sink where you will be drinking or cooking with the water. It will remove chlorine and chloramine from the water that you use at that location.
Refrigerator filters are a type of POU filters. Read my article on refrigerator filters and how well they remove chlorine.
Whichever type of carbon filter you choose, make sure it is specifically designed for removing chlorine and chloramine from water. Conventional activated carbon filters will not work as well with chloramine as they do with chlorine. Catalytic activated carbon is the best choice for removing chlorine and chloramine from water.
Alternatives to Activated Carbon for Chlorine and Chloramine
There are several water treatment technologies that can be used to remove chlorine and chloramine from drinking water. They include:
- reverse osmosis
- evaporation / distillation
- neutralization chemicals
How long does it take for carbon to remove chlorine?
The reaction between activated carbon and chlorine is very fast. An empty bed contact time of 30 to 40 seconds is more than adequate for 99% removal.
What do activated carbon filters remove?
Activated carbon filters can remove a long list of contaminants, including:
- Bad tastes and odors
- Heavy metals (specialty carbon)
- Lead (specialty carbon)
- Pesticides and herbicides
- Trihalomethanes (THMs)
What doesn’t activated carbon remove?
Activated carbon filters do not remove:
- Hard water
- Total dissolved solids (TDS)
Final Thoughts on Treating Chlorine and Chloramine with Activated Carbon
Carbon filters are one of the most popular ways to remove chlorine and chloramine from drinking water. The good news is that there are a few different types of carbon filters, and each one removes chlorine and chloramine to varying degrees.
Coconut shell activated carbon will remove the most chlorine but has the shortest lifespan. Coal-based activated coal offers great removal rates and is the least expensive. Catalytic carbons work extremely well and have the longest service life among the three types of carbon.
We hope this article has helped you better understand how carbon filters work and which type is best for removing chlorine and chloramine from your drinking water.