Air is one of the primary necessities for supporting life on earth and is made up of various components such as gases, solid particles and water vapour. An increase in industrialisation and urbanisation leads to severe air pollution. The air we breathe is becoming more polluted every passing day. Air pollution is certainly one of the most dangerous forms of pollution that affects the living world . Numerous air filtration techniques have been adopted to optimise air quality. Through filtration of air, pollutants are removed, the process effectively improves the air quality and removes the unpleasant odour in it as well. Carbon air filters are the most commonly used filters, both in small and large scale industries and are considered to be the best form of filtration. They can also be incorporated within much larger odour control systems to provide much cleaner discharges.

Activated Carbon Filter

What are carbon filters?

Carbon filters are ordinarily made from powdered carbon blocks commonly known as activated carbon which is used to remove impurities. Activated carbon filtration is an extensively used technology to reduce odours and control the emission of contaminated air. Carbonaceous materials such as coal, wood, and coconut are sources for making highly porous carbon which is in turn used in air filters to capture solvent fumes and organic compounds.

How do carbon filters control odour fumes? 

Biological vapours are a major source of atmospheric pollution and are directly culpable for a multitude of odours. Filters are very successful at cleaning the air, but activated charcoal filters not only trap dust and debris, but they also absorb fumes and odours. As they are so penetrable, activated charcoal is extremely effective. Carbon filters work by a phenomenon called “Adsorption”, the air is circulated through the activated carbon filter which is where the odour compound is trapped and retained. Carbon scrubbers pull the smell out of the air, neutralizing any odours that pass through. 

The efficiency of carbon filters

Activated carbon is used for municipal,  industrial and residential uses which include air, drinking water purification , industry,  precious metal recovery, as well as the food and beverage industry

Unlike electrostatic air filters and UV air purifier, carbon filters are a great adsorbent because of its huge surface area. While HEPA and ULPA filters capture most airborne particulates, they are naive in removing the odours that may be released from either chemicals or a by-product. Whereas an activated carbon filter has remarkable odour and pollutant reduction capabilities providing sustainable and healthy building ventilation.

Activated carbon used in carbon filters is truly a rare component. There are no other natural or man-made materials, similar to it. A carbon filter is competent as it can adsorb any vapour contaminant, organic molecules, especially solvents. It simultaneously absorbs and retains a wide variety of chemicals, catalytically destroys ozone, and is resistant to a wide range of temperature and humidity conditions. Organic compounds along with some larger molecular weight inorganic compounds, such as iodine and mercury are also adsorbed. Carbon used in filters is activated for maximising efficiency, as activated carbon becomes proficient to pull molecules to micro and macropores, attracting and holding them on its surface. Properties like surface area, pore-volume, pore radius, mesh size, ash level of activated carbon in a carbon filter are to be considered based on industrial or residential usage.

There are more than 100 types of activated carbon used for the application of purification. Depending on the industry,the operating parameters would vary, a few to list out are Granular activated carbons (GAC), Extruded or pelletised activated carbons (EAC), Powdered activated carbons (PAC), Charcoal Activated carbon cloth and fibers, and so on. The carbon filter is known for its natural filter media, low-cost & easy maintenance, safe at filtering out organic chemicals, chemical disinfectants, and some microorganisms, also it is easily available and affordable.

The carbon filters not only aid to get rid of harmful contaminants or allergens, but also eradicates unpleasant odours in the air. When carbon filters combine with HEPA filters, they can easily capture 99.97% of impurities, including particles 0.3 microns or larger. These are especially favourable to patients who suffer various allergies or are diagnosed with an illness, as a result of impure air. Another astonishing property of carbon filters is that it can recycle itself and facilitate a better environment with the use of activated charcoal.

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