Retention
Pollutants will either be retained by adsorption on the surfaces or accumulated in their inter-granular space, where they may form concentrations retaining their original chemical composition, or substances that have been altered by various chemical reactions. Pollutants retained thus on the soil surface, or in its interstitial space, may be organic, inorganic, or a mixture or complexes of both. The mechanisms of their interaction with the soil will thus depend upon physical parameters prevailing in the soil medium, such as temperature, moisture content or salinity of the soil water, as well as upon their own physical and chemical properties.