Preparation of modified Mg/Al layered double hydroxide in saccharide system and its application to remove As(V) from glucose solution

Abstract

A starch modified Mg/Al layered double hydroxide (LDH) adsorbent was firstly synthesized by co-precipitation method. The adsorbent was characterized by Fourier transform infrared spectrometry (FT-IR), X-ray fluorescence spectrum (XFS), X-ray powder diffraction (XRD) analysis, scanning electron microscopy (SEM), N2 adsorption–desorption analysis and thermogravimetric analysis (TGA). The experimental results indicated that high surface areas had been achieved after the removal of starch molecules through calcination (denoted as C-S-LDH). The maxium adsorption capacity of C-S-LDH for As(V) was increased by 36.0% compared with calcined LDH (C-LDH) at pH 7.04 in glucose solution (C-S-LDH: 8.141 mg/g, C-LDH: 5.987 mg/g). The kinetic study showed that the adsorption of As(V) by C-S-LDH was well represented by mixed surface reaction and diffusion-controlled (MSRDC) kinetics. These results have important implication for the design of absorbents in complex system.