Question

How does the absorption capacity of the regenerated activated carbon compare to that original activated carbon? Explain why there is a difference.

Answer 1

Adsorbate: The substance which has to get stick (adhere) to the surface.

Adsorbent: The material which has to stick the adsorbate. Here in this question, activated carbon is adsorbent.

The adsorption capacity (mg of adsorbate / g of adsorbent) of the adsorbent is dependent on the surface area of the adsorbent. Adsorption is surface phenomena and it requires active sites or pores to be available on the surface of adsorbent.

In the case of original activated Carbon as the adsorbent, all of its active adsorption sites are free and hence the chance of adsorbate to get adsorbed on its surface is maximum. So, it can adsorb more milligram of adsorbate per every gram of adsorbent. Adsorbate capacity of the original activated carbon is high.

    

In the case of regenerated activated Carbon as the adsorbent, some of its adsorption sites are not free. Some of its pores might have been already occupied by chemicals or the past adsorbates or even deactivated chemically, physically or by coking. So the chance of adsorbate to get adsorbed on its surface is lowered. So, it can adsorb lesser milligram of adsorbate per every gram of adsorbent than its original counterpart. Adsorption capacity of the regenerated activated carbon is low.

Note:

There is a spelling mistake in writing the question. It should have been Adsorption not absorption. Please correct.