In physiosorption, or physical adsorption, molecules of pollutants will be
attached to the surfaces of soil grains by Van der Waal forces, which are
known to be weak long range forces. The amounts of energies involved in
such attachments are normally of low magnitudes and are not sufficient for
bond breaking. Thus, pollutant molecules sticking to the soil surface will
retain their chemical identities, although they might be stretched or bent on
account of their proximity to the surface.