3.2 ADSORPTION
Adsorption: “Adsorption” may be defined as the process of
accumulation of any substance giving higher concentration of molecular
species on the surface of another substance as compared to that in the bulk.
When a solid surface is exposed to a gas or a liquid, molecules from the gas
or the solution phase accumulate or concentrate at the surface. The
phenomenon of concentration of molecules of a gas or liquid at a solid surface
is called adsorption. “Adsorption” is a well established and powerful
technique for treating domestic and industrial effluents. In water treatment,
the most widely method is “adsorption” onto the surface of activated carbon.