What Are Activated Carbon Filters?
by Carl Jensen
Plumber, Welder, Contractor
> 2 min read
Whether you simply want to improve the taste of your drinking water or extract contaminants and harmful microorganisms from your household supply, you should invest in an activated carbon filter.
These cost-effective units come with integrated and condensed carbon-based media layers. When your contaminated water passes through this block, the carbon physically absorbs the chemicals, removing them from your water.
Activated carbon filters also effectively remove chlorine from your domestic water supply, leaving you with water that’s clean and odorless.
There are different types of activated carbon filters, from those with coconut shell mixed media to others with anthracite coal components.
HERE ARE OTHER QUESTIONS THAT YOU MIGHT HAVE ABOUT WATER:
What Exactly are Activated Carbon Filters?
An activated carbon filter contains carbon-based media that extracts unpleasant smells and tastes from your water supply. These media effectively remove contaminants and harmful chemicals like chlorine, herbicides, and various destructive trihalomethanes (THMs) from your drinking water.
When your contaminated or unclean water flows through these media, the chemicals and impurities in this water become trapped in the carbon, remaining there while the rest of the supply passes out the other side of the filter. This process purifies your domestic water supply.
There are three main types of carbon media that you can use to extract harmful microorganisms from your household water.
Coconut shell media layer
This media layer is an eco-friendly option: coconut fruit harvesting is a sustainable and controlled practice worldwide. High-quality coconut shell carbon is dense and microporous, making it especially effective at extracting and absorbing harmful microorganisms during the filtration process. These carbon blocks can filter microbes and pathogens that are as small as 0.5 microns in size.
You’re very unlikely to get an allergic reaction from this type of media, and the coconut layer helps to remove man-made chemicals like herbicides and pesticides from your tap water.
This carbon-based layer is made up of charred, blistered wood. It is an especially porous medium that effectively removes organic contaminants, lead, pesticides, and harmful disinfection by-products from your water supply.
Despite its efficacy as a filter, wood-mixed media is less commonly used in a modern activated carbon filter than the coconut shell media. It’s not as environmentally friendly as its coconut shell counterpart due to mass-scale, unsustainable deforestation and clear-cutting.
Anthracite coal filter
Anthracite coal is a hard, dense material that helps to purify your domestic water supply. This type of coal contains the highest carbon concentration compared to all other carbon options available, making it an efficient and effective filtration medium.
This coal also works to extract sediment, dirt, and larger grains from your water, lowering the supply’s turbidity rating and protecting you from developing gastrointestinal issues from drinking impure, murky water.
You could also choose a carbon-based media filter that’s made of lignite coal or powder. This type of condensed material is produced by steam activation: this is a 2-stage process where the coal is first carbonized and then activated to create wider pores. This activation also increases the media’s internal surface area, allowing it to absorb and trap a large number of contaminants.
Different Shapes of Activated Carbon Media
There are three major activated carbon media shapes. The shape of the carbon media affects the surface area, which can impact its absorption capabilities. The shape can also inhibit or enhance the water flow. You can buy filters that contain an extruded form of carbon, or you might prefer a unit with an integrated powdered type. You can also find models with a granular form of carbon.
Here’s a quick rundown of the main differences between the three different shapes of carbon media.
Granular activated carbon (GACs)
Out of the three options, these carbon-based granules allow your household supply to flow through the filter the quickest, which means you’ll have clean, purified water faster.
GACs also tend to last for a longer period than their powdered counterparts, and they’re easy to reactivate if you want to use them again and again.
However, these granules can also miss various contaminants during the filtration process. The dirty water supply can sometimes siphon its way through these media, creating a hole that’s big enough for dangerous microorganisms and pathogens to get through and remain in your water supply.
Powdered activated carbon (PACs)
These powdered carbon particles are finer than the granules, and they’re a cost-effective option. A PAC filter’s internal surface area is greater than that of a GAC option, and the carbon is more compact: this means that you won’t have as many problems with water channeling through a weak spot in the carbon media layer as you might with the granules.
Filters with PACs will take longer to clean your water than those with larger granules, so bear that in mind if you have higher household water demands.
Extruded carbon (pellets)
These pellets are dense and compact, with diameters of between 0.7mm to 5mm. They have a low pressure drop, which means that you won’t experience any inconsistencies or failures in your household’s water system. They’re also durable and contain very little dust: if you have a dust allergy, you won’t need to worry about ingesting any allergen particles when you drink tap water.
"The shape of the carbon media affects the surface area, which can impact its absorption capabilities."
The Bottom Line
If you’re looking for a cost-effective way to remove carcinogens, contaminants, dirt, and unpleasant odors from your household water supply, you should invest in an activated carbon filter. These units contain a carbon-based media layer that is compact and dense, with a vast internal surface area that absorbs nearly all of the harmful microorganisms from your contaminated water.
These filters are especially effective at removing chlorine, VOCs, THMs, pesticides, herbicides, and nitrates from your household supply, helping to protect you from developing skin rashes, kidney damage, or cancer when you drink your tap water.
You’ll also find that activated carbon filters do a great job of removing any unpleasant smells from your drinking water. They extract excess chloride from your supply, taking away that nasty, briny taste that this mineral causes in water.
About the Author
Carl Jensen is a plumber with over 50 years of experience in the industry, as well as related jobs like underwater welding. He runs a successful plumbing practice in Tampa, Florida, and contributes his plumbing expertise to our DIY articles, and helps to fact check and consult on most of our other stuff to boot.