Removal of Chromium from Aqueous Solution by Thermally Treated Mgal Layered Double Hydroxide

Abstract

MgAl based layered double hydroxide (MgAl-LDH) was used as adsorbent for the removal of chromium oxyanion from an aqueous solution. MgAl-LDH was synthesized successfully using co-precipitation method, and was characterized by X-Ray Diffractometer (XRD), Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). MgAl-LDH was thermally treated for improving the chromium adsorption. Samples were treated at 220°C and 450°C. A negligible difference of total chromium adsorption capacities was observed between MgAl-LDH₀₀₀ and MgAl-LDH₂₂₀ as 12.56 mg/g and 11.01 mg/g. The maximum chromium adsorption capacity of MgAl-LDH was 88.07 mg/g at 500g/l chromium concentration for MgAl-LDH which has been thermally treated at 450°C (MgAl-LDH₄₅₀). The results indicated that memory effects of thermally treated MgAl-LDH at certain temperatures were retained and enhanced chromium removal efficiency.