Magnetically Recoverable CMC/Fe3O4 Nanocomposite for Efficient Removal of Hg(II) and Cd(II) ions from the Aqueous Solution

Abstract

ABSTRACT Heavy metals such as Mercury and Cadmium are highly cytotoxic metals when released into the environment and pose serious hazards to the ecosystem. The current study introduces CMC/Fe3O4 nanocomposite as an effective, magnetically recyclable, low-cost, and environment-friendly biopolymer-based adsorbent for removing these harmful contaminants from waste water. This nanocomposite was synthesized by ultrasonic assisted coprecipitation method and characterized using X-ray diffractometer, scanning electron microscope, BET surface area, Fourier-transform infrared spectroscopy, etc. Series of batch experiments were carried out at room temperature to determine the adsorption capacity of CMC/Fe3O4, which is found to be 243.52 mg g−1 and 414.04 mg g−1 toward Hg(II) and Cd(II), respectively, at optimum conditions. Optimum parameters for Hg(II) were pH 7, initial concentration 200 mg L−1, and 0.02 g of adsorbent loading, while for Cd(II) experiments were conducted using pH 6, initial concentration 500 mg L−1, and 0.03 g of adsorbent. The adsorption was well described by the Langmuir isotherm model and Pseudo-second order kinetic model, and the thermodynamic study reveals spontaneous and endothermic nature of adsorption.