Removal of U(VI) from aqueous solution using carboxymethyl cellulose-modified Ca-rectorite hybrid composites

Uranium (VI), as a toxic contaminant, is a potential detriment to human health and environmental safety. In this experiment, carboxymethyl cellulose/Ca-rectorite composite material (Ca-REC/CMC) was prepared by crosslinking reaction to remove U(VI) from the liquid. The crystal structure was detected by X-ray diffraction (XRD) and surface structure and morphology of the materials were investigated by scanning electron microscopy (SEM). The surface functional groups of prepared materials were detected by Fourier transform infrared spectroscopy (FT-IR). The adsorption capacity of Ca-REC/CMC improved obviously after being modified by CMC. The adsorption capacity of Ca-REC/CMC was closely related to ionic strength and pH. According to thermodynamic parameter calculation, the adsorption process was endothermic and spontaneous. Adsorption isotherms could be depicted perfectly by the Langmuir model. Ca-REC/CMC maintained stability and regeneration after recycling six times. The adsorption mechanism, including electrostatic interactions and ionic interaction, was investigated by the X-ray photoelectron spectroscopy (XPS). Ca-REC/CMC is considered as remarkable potential material for removing U(VI) from the water environment.