Preparation of an amino-modified biochar supported sulfide nanoscale zero-valent iron composite and its efficient removal of U(vi) from wastewater by adsorption and reduction

Nanoscale zero-valent iron (nZVI) was cured by vulcanization and biochar functionalization to overcome the tendency of oxidation and aggregation, and the sulfurized nano-zero-valent iron functional material supported by amino biochar (SnZVI-BC-NH2) was obtained, which was used to remove U(VI) from wastewater in this study. A variety of measurements (SEM, TEM, XRD, BET, VSM, FT-IR, and XPS) were used to characterize the morphology, structure, magnetic properties, characteristic functional groups and chemical bonds of SnZVI-BC-NH2. Analysis results confirm that the aminated biochar can support sulfurized nZVI well. The good kinetics, thermodynamics, and large removal capacity data (at pH 6, T = 298 K, Q(m) = 158.1 mg g(-1)) indicate that SnZVI-BC-NH2 has excellent removal performance for U(VI), and the experimental data are in good agreement with the pseudo-second-order kinetic model. Cycling and anti-oxidation tests demonstrate that the FeSx shell plays a crucial role in enhancing the removal of SnZVI-BC-NH2 on U(VI). XPS and FT-IR analysis results show that SnZVI-BC-NH2 removes U(VI) through the synergistic effect of adsorption and reduction.