Iron oxide slag nanocomposites in removal of hexavalent chromium

Abstract

Hexavalent chromium is the most toxic form of chromium and causes various environmental impacts. The present study highlights nanocomposite metal oxides in the removal of hexavalent chromium. Especially, the role of iron oxide in the form of hematite (ε-Fe2O3) in slag nanocomposite in chromium removal is revealed. Metal oxides of steel slag are sintered at 600°C and the removal of chromium is studied using diphenyl carbazide (C13H14N4O) method by UV–vis spectrophotometer. Cr (VI) forms pink colour with DPC in acidic condition and is studied at 540 nm. Cr (VI) removal is studied with various factors including initial Cr (VI) solution concentration, metal oxides dosage, contact time and pH. Elemental composition of steel slag nanocomposites (metal oxides) is characterised using EDAX and XRF analysis. Surface morphology of slag nanocomposites has been characterised using SEM analysis. Structural bonding of slag nanocomposites before and after chromium removal is studied using FTIR analysis. Atomic absorption spectroscopy (AAS) is emphasised for the total chromium content before and after removal. The results can be developed as a conventional technology in treating chromium removal.