Decomposition of Organic Materials Adsorbed on Soil

Sorption refers to the acquisition of a chemical species from the aqueous phase by a contiguous solid phase. The three principal sorption mechanisms are adsorption, precipitation, and absorption (or incorporation). 

For example, certain soil components can act as adsorption sites for organic materials and facilitate their photodecomposition upon exposure to sunlight. In the case that the soil component is a semiconductor, this process can occur through the formation of electron-hole pairs (i.e., photocatalysis, see Chapter 10). Photochemical processes may then affect soil components and composition. 

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