Swelling behavior of montmorillonite-supported hybrid hydrogel adsorbent

Heavy metal pollution has attracted great attention due to the dangers to the human health and biological environment. In this study, a composite hydrogel adsorbent based on acrylic acid monomer/wheat bran, supported by montmorillonite was synthesized using in-situ polymerization method and swelling properties was investigated using bath techniques. The scanning electron microscopy was used to characterize the morphology of adsorbents and displayed a sheet-like and porous structure. The optimum amount of montmorillonite, wheat bran, acrylic acid and N,N -Methylenebisacrylamide for synthesizing montmorillonite-supported hydrogel adsorbent (MHA) was determined based on design of experiment using Taguchi method. The incorporation moderate amount of these materials results in enhancement of swelling behavior of the MHA. The initial swelling kinetic was Fickian type diffusion and the whole swelling process was good fit for Schott’s pseudo-second order model. The equilibrium time for the process was determined as 2 h. These results presents that MHA is promising adsorbent for metal removal from aqueous solution.

Keywords:

Adsorption , Hydrogel , Swelling , Montmorinollite , Wheat bran