BIOAVAILABILITY OF ELEMENTS FOR EFFECTIVE PHYTOREMEDIATION AND PHYTOMINING: THE ROLE OF RHIZOSPHERE PROCESSES

The success of phytoremediation (especially phytoextraction) and phytomining depends
heavily on the bioavailability of target elements, which, among others, is a function of soil mineral
phases, soil organic matter, pH and redox potential. The use of soil additives which, e.g., change
soil pH or increase the amount of chelating compounds, has been propagated in the past in order to
desorb the target elements from the soil matrix. These additives, however, may have negative
environmental consequences by causing leaching of toxic elements from the soil due to enhanced
mobility in the soil solution. For this reason less dangerous alternatives are necessary which use the
natural capacity of plants to increase availability of target elements in their root environment.