Migration and Accumulation of Silicon Compounds in Soil-Water Systems

Migration and Accumulation of Silicon Compounds in Soil-Water Systems Silicon is permanently entering soil solution and ground waters as a result of hydrolysis of dispersed alumosilicate and dissolution of various silicon minerals, like quartz. 

Similar deposition effects are related to transpiration or freezing of soil solutions. Sometimes, these processes are accompanied with the formation of silicon layers up to 4-5 m thickness, as in the Mississippi River valley. 

The Si entering biogeochemical food webs leads also to formation of biogenous depositions. Diatomic algae, radiolaria, some plants (bamboo) may bioaccumulate the soluble silicon with subsequent transformation in amorphous silicon compounds, like opal. However, this process seems reversible and opal may be de-polymerized back to colloidal and soluble species of silicon (Kovda, 1984). 

---