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

摘要

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 K_2Cr_2O_7 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 °C. There was 100% reduction achieved in pH 3 - 5 at 30 and 45 min respectively. At different temperature time taken for 100% reduction at 0 °C, RT (30 °C) and 40 °C was 120, 60 and 30 min 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.