For centuries humans have been harnessing the power of activated carbon in making our daily lives cleaner and healthier.
So far people been very creative in terms of applying the powerful adsorption properties of activated charcoal not just in various industries but also in our own homes.
A bit of carbon history...
The first recorded usage of carbon was in 1500 BC; but the earliest known use was by the Egyptians and Sumerians in 3750 BC. It appears that early humans used carbon in bronze manufacturing and for medicinal purposes specifically for adsorbing foul odors in decaying wounds and from within the digestive tract.
Then around 400 BC Hippocrates (Known today as the father of medicine) and Pliny recorded their use of carbon for treating various health conditions including epilepsy, chlorosis and anthrax.
And in the following years, apart from medicinal applications, man discovered more carbon applications in many different areas including water purification, agriculture, gas purification, food processing, and odor control.
It wasn’t until the 20th century that activated carbon or activated charcoal came into being. In 1901, Von Ostrejko founded the basis for the development of commercial activated carbon. The first ever industrially produced and commercially released activated charcoal was by the Fanto Works in Austria with the trade name ‘Eponit’.
Eventually, further developments took place including the use of better processing methods and thus the production of more superior quality activated carbons by the year 1913. Between 1914 and 1918 the use of poisonous gases in battlefields during World War I encouraged the development of large scale production methods specifically for producing highly adsorbent activated carbon suitable for military use. This gave birth to super adsorbent granular activated carbons.
Expectedly, the post war period saw more advanced commercial developments in terms of activated charcoal production as the world continuously saw the effective and useful properties of carbon. New raw materials were used such as coconut and almond shells. Today, hardwood, sawdust, and bamboo have also been used as a raw material for producing great quality activated charcoal for both industrial and household uses.
How does activated charcoal work?
Activated charcoal works by attracting and binding unnecessary particles and toxic substances in its very fine pores. And it is quite effective in doing so due to its highly porous composition.
These minute holes give the charcoal a wider surface area which allows liquids or gases to pass through it and bind with the carbon. Activated carbon adsorbs many types of contaminants, including unwanted smells, some drugs, and chemical compounds such as chlorine.
But not all substances are adsorbed by carbon. These include compounds such as nitrates, sodium, and fluoride. Because adsorption works by attracting the impurities to the charcoal surface, it eventually becomes filled. Overtime, activated carbon filters become less powerful and needs to be replaced or recharged.
So again overall, activated carbon doesn’t absorb particles or chemicals; it adsorbs them. Think of a sponge - it attracts water for example but water molecules just attach to it and not necessarily combine with it to form another solution or compound. That is also how activated charcoal works as an adsorbent.
Contaminated Water/Gas → Passes through the Activated Carbon filter → Activated carbon traps the impurities found in water or air → Clean air/water is released
Activated carbon can either be ingested (medicinal grade) for treating poisoning or for detoxification, or used as an external purifier in both liquids and gases. It is important to note however that activated charcoal is different from the charcoal you use for cooking barbecue at home!
Does activated charcoal ‘de-adsorbs’ once full?
Some people worry about their activated carbon filters releasing unwanted toxins back once the pores become filled. While it doesn’t ‘de-adsorb’ toxins or odors it already adsorbed, it may become less effective; hence the need for a replacement or recharge.
How to recharge activated carbon?
Depending on your usage, it may or may not be advisable for you to recharge your activated charcoal. For example you can try recharging an activated charcoal deodorizer or air filter by laying it out in the sun for 30 minutes and be able to prolong the life of your deodorizer.
However it’s not recommended for you to recharge an activated carbon water filter used for drinking as heating may trigger some chemical reactions in the chemicals that are already bound in the carbon. And this can be potentially poisonous.