THE ELIMINATION CAPACITIES OF CR(VI) REDUCTION BY FERROUS IRON (FES2) IN WATER AND THE KINETIC MODEL OF THE REACTION

Abstract

Hexavalent chromium (Cr(VI)) is widely used in long-term industrial applications for its ability to inhibit rust formation. Cr(VI) is a known human carcinogen. The aim of this research was to use pyrite particles (FeS2) to reduce Cr(VI) in water. The main objective of this work was to study the reaction mechanisms, focusing on the role of ferrous Fe(II). The results show that the rates of Cr(VI) reduction by Fe(II) depend on pH, temperature and Fe(II) and Cr(VI) concentrations, and that the reduction capacity of pyrite is terminated during about seven steps. The results showed that the effect of pyrite on Cr(VI) reduction appears to differ in the presence of different anions.

This study has shown that the use of pyrite (FeS2) for Cr(VI) removal by a reduction reaction is applicable to Cr(VI)-contaminated solutions. The rapid reduction of Cr(VI) suggests that abiotic reduction of Cr(VI) may be an important transformative process in natural systems and iron metal-based remediation technologies. Chemical reduction of Cr(VI) to Cr(III) by pyrite (FeS2) may be a less costly approach to remediation.