Removal of hexavalent chromium anions from solutions by pyrite fines

Bench scale experiments were conducted in the laboratory, aiming to the removal of hexavalent chromium from aqueous solutions, by dispersed pyrite fine particles. Pyrite (iron sulphide mineral), was found to act as an efficient Cr(VI) reducing agent. The resulted hydroxo-Cr(III) species were found to be precipitated (and removed) onto the pyrite particles. The process mechanism was also examined by ς-potential measurements and speciation studies. Promising results were obtained at highly acidic pH values (around 1–2), showing an interesting aspect of fine (solid waste) mineral particles utilization, in the removal of a priority pollutant.