Adsorption in Activated Carbon- How it works ?
Activated Carbon is a versatile Adsorbent having exemplary disinfecting and decolourization properties.
Since ancient times Activated Charcoal has been used for multiple purposes – purification as well medicinal, dating back 400 BC the civilizations were using charred wooden barrels to store water, and by 50 AD Hippocrates was using activated charcoal to treat multiple ailments and was one of the most effective treatments for intestinal ailments.
Activated Carbon works on the principle of Adsorption, which is much like absorption, but adsorption involves a little more complex process, wherein atoms, ions or molecules from a substance (it could be gas, liquid or dissolved solid) adhere to the surface of the Adsorbent.
It’ll be my endeavour herewith, through this blog to help you understand this complex adsorption process as simple as possible, and for which I’m going to take help from a class 7 school science topic which surely you’d be able to recall – Photosynthesis.
Photosynthesis – is a topic related to nutrition in plants, wherein it explains how plants make their own food. The plant draws water & minerals from the ground below through the roots, transporting this water with minerals through the complex network of veins present inside the plant, up to the leaves, where the chlorophyll present in leaves and in presence of sunlight and co2 in the atmosphere, this water with minerals helps produce food (glucose) for the survival of the plant. These very veins which transport water and minerals from the ground below up to the leaves, also help distribute this food/nutrient produced on the leaves to the entire plant/tree.
Now, let’s visualise and understand that in an Activated Carbon similar type of vein structure exist and which in adsorption terminology are as Pores, as per IUPAC (International Union for Pure & Applied Chemistry) Pores as per their radius (r ) are categorised, as;
- Micropores : r < 1 nm
- Mesopores : 1 < r < 25 nm
- Macropores : r > 25 nm
- Macropores are the trunk of the tree
- Mesopores are the branches
- Micropores are the leaves.