Interaction of U(VI) with amine-modified peanut shell studied by macroscopic and microscopic spectroscopy analysis

Peanut shell, a widely available agricultural waste, was successfully grafted with quaternary ammine groups on its surface by using amination modification. The sorption mechanism of U(VI) on the amine cross-linked peanut shell (PNN) was examined by batch experiments and spectroscopy analysis. The physical adsorption was dominated by the liquid film diffusion and the intra-particle diffusion, whereas the chemical adsorption was dominated by surface complexation with quaternary amine groups and carboxyl groups. The maximum adsorption capacity of U(VI) on PNN was calculated to be 574.81 mg g−1 at pH = 6.0 and T = 298 K, which was much higher than that of U(VI) on pristine pure peanut shell and many other materials. Consideration of the high sorption efficiency and eco-friendliness of peanut shell, PNN presented promising potential in the preconcentration of radionuclides in radioactive pollution management.