REMOVAL OF HEXAVALENT CHROMIUM ANIONS FROM SOLUTIONS BY PYRITE FINES

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