Abstract
A novel chelating adsorbent, modified sawdust (MS), was synthesized by grafting quaternary ammonium on the cellulose of sawdust, was first designed for high performance U(VI) removal. The property MS was characterized by scanning electron microscopy, energy dispersive X-ray, X-ray diffractometer, and Fourier transform infrared spectroscopy. Removal efficiency of U(VI) for MS and raw sawdust (RS) was evaluated at different dosages, pHs, contact times, and temperatures. Results showed that maximum U(VI) removal efficiencies of 99.7% and 72.8% for MS and RS, respectively, were observed at adsorbent dose of 0.1g, contact time of 2h, pH 4.5, and temperature 30 degrees C. Adsorption equilibrium of U(VI) onto MS was well described by the Langmuir isotherm model. Also, the thermodynamic result showed that the adsorption process was feasible, spontaneous, and endothermic in nature. Adsorption kinetic data were fitted well with a pseudo-second order model. High U(VI) removal performance for MS was attributed to the adsorption of U(VI) on amine groups, followed by U(VI) chelation. Results indicate MS has great potential in treating uranium-contaminated water.