In a world where everything we eat, drink, and breathe is contaminated with pollutants, it’s important to rely on filters. Of course, not all filters serve the same purpose, and therefore we must understand the different types of the filter as well as which one would be ideal for your specific need.
Here we talk everything about activated carbon air filters, their specific role in filtering out pollutants from air purifiers, providing us with fresh and clean air to breathe and stay healthy. Want to know more about air purifiers in general? You can read our article on the working of Air Purifiers to learn everything there is to learn about them.
What Is Activated Carbon?
Activated carbon is often known by its alternative name – activated charcoal – possibly because it does look quite similar to charcoal too. It’s a type of carbon which is processed to obtain a large surface area. The processed carbon has very small, low-volume pores which lend a surface for adsorption or chemical reactions.
To explain this further, a gram of activated carbon has more than 32,000 sq ft., while a teaspoon of it has approximately the surface area as large as a football field. Owing to this incredibly vast area, activated carbon has several vital uses in several domains. However, with more chemical treatment, its adsorption properties can be further improved as well.
Coming to the composition, activated carbon is generally obtained from a carbonaceous source, such as wood, bamboo, sawdust, coconut shells, coir, petroleum pitch, and different types of coal. Also, it’s worth noting here that activated carbon isn’t the same as regular carbon. The prime difference lies in the numerous tiny pores across its surface, which get formed only when carbon is “activated”.
How Does Activated Carbon Filter Work?
One of the many applications of activated carbon is the activated carbon filter, also known as a charcoal filter. It comprises of a granular or powdered block of activated carbon which has innumerable tiny pores for adsorption. The filter is extremely porous and is used as an effective filtration method for gases, chemicals, and Volatile Organic Compounds (VOCs). It, however, is unable to filter out some very tiny particles such as dust, dust mites, pet dander, or pollen present in the air. It is hence, often seen complementing a HEPA grade filter in most high-end air purifiers.
Similarly, there may be other filtration systems working their part in an air purifying machine or on their own as separate air cleaners. You may find the most prominent ones with their respective functions listed below:
- True HEPA vs HEPA type filters : Know the difference
- What is an Air Ionizer? Do Ionizers emit Ozone?
- The Untold truth about Ozone generators
This is how an activated carbon filter works:-
- The carbon filter air purifier eliminates gas molecules through a process called adsorption, which shouldn’t be confused with absorption because both are different. During the adsorption process, air pollutants stick to the exterior of the filter.
- Air purifiers hardly function on activated carbon filters as a standalone. They are mostly used in addition to the HEPA filter because the latter has the ability to filter out fine particles as well which an activated carbon filter can’t.
- High-quality activated carbon filters comprise potassium permanganate or potassium iodide for removing potentially harmful chemicals, formaldehyde, and wildfire smoke.
How Long Does Activated Carbon Last?
The only disadvantage with this filter is that it doesn’t last very long. This reduces their efficacy in functioning as a significant air pollutant filter in air purifiers. An activated charcoal filter generally has a life span of just about 2-4 weeks. You’d then need to change the filter to restore its efficiency or to keep it running smooth and hassle-free.
The short life span of the filter is owed to the absorption process wherein the pollutants captured get filled up inside the activated carbon bed. Upon saturation of the bed, the filter can no longer absorb pollutants, leading to a demand for change.
One good thing in all this is that activated carbon as an element is reusable. Its porous property allows the air filter to be recycled. This can be done by baking out the odours present in the filter – once done. It’s ready for reuse.
That said, it must be remembered though that the recycled filter in the air purifier can only be reused for a maximum of 2-3times, after which it must be replaced for efficient filtering against smoke, odours, chemicals, and other such air pollutants.
How To Clean Activated Carbon Filter?
Make sure that your activated charcoal air filters specify “washable” on the label; else you’re likely to damage them by washing. They can be washed though if they say so on the label, however, you’d need to know the exact technique of cleaning your air filter.
The good news though is that activated carbon filters don’t necessarily need washing because it’s used to adsorb odours and doesn’t capture tiny pollutant particles. As such, there’s no solid particle to get stuck in the filter which needs to be cleared with washing. For the same reason, you wouldn’t even need a brush or vacuum to clean your Activated Carbon Air Filter.
Then how can you actually “clean” the filter to keep it working efficiently? The best way to do so is to let it get some direct sunlight. Place the filter under direct sun for about 2-3 hours, and it would be as clean as new!
As mentioned above, activated carbon filters aren’t to be washed, so if you do find some fault in your air purifier time to get the filters replaced or get a new Air Purifier altogether.
Other Uses of Activated Carbon
Air purification is not the only significant use of activated carbon; the element has a wide range of equally useful applications to its credit, some of which are listed below:
- Medical use – Considerably used in the treatment of drug overdosing, poisoning, and to improve symptoms of indigestion and diarrhoea.
- Industrial use – Commonly used in finishing of metal; it’s the primary agent used for getting rid of any impurity in metals like nickel.
- Analytical Chemistry use – Owing to its high adsorption rate, activated carbon is primarily chosen for purifying organic molecule and chemical solutions.
- Agricultural use – Largely used in organic farming and even livestock production – it is used as an additive to animal feed, natural pesticide, processing aid, and disinfectant. It’s also a great processing agent in the winemaking process, helpful in absorbing odour and other unwanted colour pigments.
- Environmental use – Useful in groundwater remediation and clean-up of spills
- Cosmetic use – Active ingredient in most shampoos, toothpaste, and face masks as it can effectively capture toxins and contaminants and washes them away.
- Distilled beverage use – Effective purifier in the manufacturing process of whiskey and vodka, it can help eliminate organic impurities from such beverages.
- Mercury removal use – A majority of coal-fired power plants and industries emit mercury which is a dangerous element. Activated carbon is used in conjunction with halogen and sulphur to capture mercury gas and filter it from the air.
- Gas storage use – Efficient storage source for fuel gases in low-mass, low-volume, and low-pressure environments.
- Space technology use – An active component in the life support systems of astronaut spacesuits. The filter is used to remove contaminant traces found in the oxygen flow to the astronaut, which includes their body odour too.
The above 10 uses are only a sample of the incredibly wide application of activated carbon in various industries. Its vast usefulness is still being researched by scientists for exploring newer and innovative uses of this fantastic component.
Activated carbon is such a useful element that it has found its way in nearly every stream of practical use in today’s world – whether it’s the medical community or agricultural farming, space technology or simple purification of water and air that runs or floats around in our homes.