Explaining Activated Carbon Filtration

Activated carbon filtration is an advanced filtration method commonly used to purify air and water. Its unique ability to absorb and trap harmful chemicals makes it one of the most efficient filtration systems available today. Whether in an air filter or water filter, activated carbon has become a popular solution in both residential and industrial settings. But how does it actually work? Today, let’s explore the process behind activated carbon filtration!

What Is Activated Carbon Filtration?

Activated carbon filtration involves using activated carbon, a highly porous form of carbon that effectively captures impurities from air or water. The "activation" process increases the carbon's surface area, making it incredibly absorbent. This enhanced surface area allows the activated carbon to trap a large number of contaminants, such as volatile organic compounds (VOCs), chlorine, and odors. The increased porosity is why we say that the carbon is active; normal carbon isn’t so good at attracting and trapping pollutants. 

Activated carbon is commonly made from materials like wood, coal, petroleum pitch, and even organic waste products like coconut shells, coir, and nut shells! These materials go through a heating process that removes non-carbon elements, leaving behind a highly porous structure ideal for trapping molecules. 

Why Does Activated Carbon Work?

Activated carbon works through a process called adsorption, where molecules from air or water stick to the surface of the carbon. The reason activated carbon is so effective is due to its large surface area and highly porous structure, created during the activation process. When contaminants come into contact with activated carbon, they are drawn to its surface and held there by weak electrical forces known as Van der Waals forces. 

These forces cause molecules, especially organic compounds and gases, to stick to the carbon's surface. The carbon itself has a slightly negative charge, which attracts and holds positively charged particles, including many pollutants and impurities. Additionally, the porous nature of activated carbon allows it to trap a wide range of molecules. This combination of high surface area from the pore structure and electrical charge makes activated carbon a powerful tool for filtration.

What Does Activated Carbon Do in an Air Filter?

In air filters, activated carbon plays an essential role in removing chemicals from the air. While traditional air filters capture particles like dust, pollen, and pet dander, they aren't effective against gaseous pollutants. This is where activated carbon filtration comes in!

Removes Harmful Gases and VOCs

One of the primary functions of activated carbon in air filters is to remove volatile organic compounds (VOCs), which are harmful chemicals found in paints, cleaning supplies, and household products. These compounds can off-gas into the air, causing poor indoor air quality. Activated carbon effectively traps these VOCs, reducing exposure to these hazardous substances and improving overall air quality.

Eliminates Odors

Another benefit of activated carbon filtration in air filters is its ability to eliminate odors in both air and water. This has made it very popular for households, offices, and industrial spaces where odor control is important.

Enhances Overall Air Quality

When used together with particle filters like HEPA filters, activated carbon helps create a more comprehensive air purification system. While the particle filter captures fine particles, activated carbon tackles gaseous pollutants and odors, making the indoor environment safer and more pleasant.

What Does Activated Carbon Do in a Water Filter?

Activated carbon filtration is also widely used in water treatment systems, providing an effective way to remove impurities and contaminants from drinking water. 

Removes Chlorine and Chloramines

One of the most common uses of activated carbon in water filters is to remove chlorine and chloramines. Chlorine is often added to municipal water supplies to kill bacteria, but it can give water an unpleasant taste and smell. Activated carbon has an interesting relationship with these chemicals. It doesn’t actually absorb or adsorb chlorine; instead, the carbon and chlorine have a chemical reaction and the carbon converts the chlorine to chloride, which is safe to drink.

Filters Out Organic Compounds

Activated carbon is highly effective at removing organic compounds from water, such as pesticides, herbicides, and pharmaceutical residues. These compounds can enter water supplies through agricultural runoff or industrial waste, and activated carbon traps them, preventing them from passing through the filter. However, it does not remove some chemicals, like sodium and fluoride– and it won’t change your water hardness or microbial levels.

Limits Heavy Metal Removal

While activated carbon is excellent for removing organic compounds and chlorine, it’s worth noting that it is less effective at removing heavy metals like lead, mercury, and arsenic. If you live in an area where these chemicals are a water concern, you will need more than just activated carbon.

Is Activated Carbon the Same as Activated Charcoal?

The terms "activated carbon" and "activated charcoal" are often used interchangeably, but there is a slight difference. Both activated carbon and activated charcoal undergo a process that increases their surface area, making them highly absorbent. The distinction typically lies in the application. Activated carbon is more frequently used in industrial applications like water and air filtration. Activated charcoal is a type of activated carbon, but it's specifically designed for medical or chemical applications. You’ll see it in personal care products like toothpaste or face masks, and sometimes even in emergency medical situations to treat poisonings.

Why Understanding Activated Carbon Filtration Matters

Activated carbon filtration is a powerful tool for purifying both air and water, making environments safer and more comfortable. Knowing how activated carbon actually works can help you make informed decisions about air purifiers, water filters, and other filtration systems. But it’s not just about carbon. Asking these questions and being curious about how the world around you works is important– we think it’s worth it to understand the rules that write the universe, and the way you understand those rules is through science.