Environmental Remediation of Hexavalent Chromium in Aqueous Medium Using Fe(II)-Montmorillonite as Reductant

Abstract

Hexavalent chromium contamination of groundwater and soil possess a significant threat to human health and the environment. The remediation by reduction, Cr(VI) → Cr(III), with a variety of reducing agents and techniques are explored for many years. In this study, Fe(II)–montmorillonite (Fe(II)–mont) was interacted with K2Cr2O7 solution at different pH and temperature. The decreasing Cr(VI) concentration was monitored by UV-Vis spectrophotometer. In general, the Cr(VI) reduction was rapid at acidic pH and increases with temperature up to 40 0C. There was 100% reduction achieved in pH 3 – 5 at 30 and 45min respectively. At different temperature time taken for 100% reduction at 0 0C, RT (30 0C) and 40 0C was 120, 60 and 30min respectively. The reduction followed by immobilization of Cr on the spent clay mineral was evident from FESEM/EDX and chemical extraction analysis. The results also revealed that the prepared Fe(II)–mont could be potentially applied as a adsorbent enabling promising applications for the removal of Cr(VI) from aqueous solution.