Redox soil metal speciation-mobilization

Biological systems do not act simply as passive sinks for metals. They also modify their chemical environment and consequently the chemical speciation and mobility of nutrient and potentially toxic elements. Their influence on the mobility of radionuclides is less widely studied than that of other metals, but is certainly as important. The relevant factors include pH, redox potential, concentration of complexing ligands in solution, and mineral weathering. The relative importance depends on the soil and on the chemistry of the element considered, and no generalities can be made. It is not surprising that elements such as Se and Tc that exist in various oxidation states they sensitive to redox conditions. For other... 

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