equilibrium sorption

Equilibrium sorption is the point where the process of a substance binding to a surface (sorption) reaches a balance, meaning the amount of the substance attaching to the surface equals the amount detaching. Imagine a sponge soaking up water; initially, it absorbs quickly, but eventually, it reaches a stage where water enters and leaves the sponge at the same rate. Similarly, in equilibrium, the rate of molecules sticking to a surface equals the rate of molecules leaving it, resulting in a stable amount of the substance on the surface over time.