A Sulfonic-Functionalized Cellulose Adsorbent for the Rapid Removal of Cerium (III) from Aqueous Solutions

The biodegradable biomass adsorbent (cellulose-g-PSS) was synthesized in LiCl/N, N-dimethyl acetamide by the free-radical grafting polymerization reaction between sodium styrene sulfonate (SSS) and cellulose. Systematic optimization was conducted on many reaction parameters, including reaction time, monomer dosage, and reaction temperature. The grafting yield of cellulose-g-PSS was 50.16%. The chemical structures, physical, and chemical characteristics of cellulose-g-PSS were characterized by FTIR, SEM, PZC, ¹H NMR, XRD, TGA and XPS. An assessment was conducted to determine the sorption of Ce (III) on cellulose-g-PSS by changing the contact time, adsorbent dosage, pH, initial Ce (III) concentration, and NaCl concentration. The process of adsorption rapidly reached a state of equilibrium within a time frame of 25 min and was well explained using pseudo-second-order kinetic and Langmuir isotherm model. The maximum adsorption capacity for Ce (III) obtained from the Langmuir isotherm model was 84.80 mg·g⁻¹. The impact of NaCl concentration on the sorption of Ce (III) and XPS analysis showed that Ce (III) ions were adsorbed onto cellulose-g-PSS through ion-exchange mechanism. As a whole, cellulose-g-PSS exhibited great potential in rare earth wastewater treatment.