What does Adsorption Mean?

Adsorption is the process in which atoms or molecules of a substance are retained on the surface of another substance.

In chemistry and physics, adsorption is a surface phenomenon in which a component tends to concentrate at the interface, that is, between one phase and another of different substances.

In adsorption, the substance that migrates to the surface is called adsorbate and the surface on which the process occurs is identified as adsorbent.

There are two types of adsorption: physical adsorption and chemical adsorption.

The physical adsorption or physisorption is the phenomenon in which the adsorbate retains its identity forming multilayers. This type of adsorption is reversible if the temperature rises and the pressure drops.

In chemical adsorption or chemisorption, the adsorbate usually loses its identity and its formation is monolayers. This process is irreversible.

The adsorption isotherms is the equilibrium relationship between the adsorbed gas and the gas pressure, in other words, it is the general relationship between the amount of gas adsorbed by a solid at a constant temperature.

Adsorption and absorption

Adsorption is a surface phenomenon that lies between two substances. The adsorbate sticks to the surface of one of the substances without being part of any of them. The composition of the adsorption is different from that of the original phases, such as adsorption with activated carbon for water dechlorination.

On the other hand, absorption is the physical penetration of one substance into another, for example, the chemical case of gas separation by means of a liquid solvent that absorbs one of the gases to create a new substance.

Adsorption with activated carbon

Activated carbon has been known as a natural purifier and detoxifier in medical treatments since 1500 BC. The large number of pores that activated carbon has helps retain on its surface the organic material that has been in contact. This property of activated carbon is called adsorption and is the main feature of its detoxifying power.