EFFECT OF pH ON THE DISSOLUTION KINETICS OF ZERO-VALENT IRON IN THE PRESENCE OF EDDHA AND EDTA

摘要

The geochemical cycling of iron has been the subject of studies for several decades. In general, the majority of this work has been focused on the weathering of ferric oxides and hydroxides (e.g., goethite [α-FeOOH], hematite [Fe2O3] and lepidocrocite [γ-FeOOH]) and their role in influencing the geochemical cycles of P, S, heavy metals, O2 and C in the environment. Unlike the afore mentioned Fe-bearing minerals, zero-valent iron [Fe(0)] does not occur naturally and requires extreme anoxic/reducing conditions to form; therefore, it is environmentally unstable relative to oxidized Fe as oxide or more complex mineral phases.