Optimizing the use of natural and synthetic magnetites with very small amounts of coarse Fe(0) particles for reduction of aqueous Cr(VI).

摘要: Abstract Remediation of highly toxic aqueous Cr(VI) includes its chemical reduction to the very insoluble Cr(III) species. In this work we investigated performance synthetic and natural magnetites different particle size sat three pH values (4, 6, 8), with purpose cost-optimizing procedure at laboratory scale. Only finest magnetite showed considerable yields, but rates were low after 25 days no equilibrium was attained. Mechano mixing finer 5% micron-sized Fe(0) increased dramatically their reductive reactivity, especially 4 8 only for sample, despite fact that same quantity added by itself reducednegligible amounts Cr(VI). Increasing concentrations in mixtures 10 15% allowed improvements reactivity intermediate-sized (of ca. 7 m2/g), not coarser samples up 20% Fe(0). This promises be an optimal technology remediation or treatment polluted environments residues, may prove beneficial industries pollution clean-up government agencies, because it uses readily available solid mineral minimizes use acid reagents.