Adsorption of Hg(II) ions from aqueous solution by thiosemicarbazide-modified cellulose adsorbent

Abstract

A highly selective cellulose-based adsorbent for mercury [(Hg)II] ion was prepared and characterized using Fourier-transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, X-ray photoelectron spectrometry, elemental analysis, and scanning electron microscopy. The results showed that functional thiosemicarbazide-grafted cellulose achieved equilibrium adsorption in 120 min, and the adsorbents had a Hg(II) ion removal rate of approximately 98.5% at a pH of 5.0. The adsorption kinetics fit the pseudo-second-order model, which indicated that the adsorption was a chemical process. Additionally, the adsorption isotherm data showed a best fit with the Langmuir isotherm model, with a maximum Hg(II) ion adsorption capacity of 331.1 mg/g. This adsorbent had a good selectivity for Hg(II) during competitive adsorption.