The magnetic iron oxide（Fe3O4） nanoparticles stabilized on the biochar were synthesized by fast pyrolysis of Fe（II）-loaded hydrophyte biomass under N2 conditions. The batch experiments showed that magnetic biochar...The magnetic iron oxide（Fe3O4） nanoparticles stabilized on the biochar were synthesized by fast pyrolysis of Fe（II）-loaded hydrophyte biomass under N2 conditions. The batch experiments showed that magnetic biochar presented a large removal capacity（54.35 mg/g）at pH 3.0 and 293 K. The reductive co-precipitation of U（VI） to U（IV） by magnetic biochar was demonstrated according to X-ray diffraction, X-ray photoelectron spectroscopy and X-ray absorption near edge structure analysis. According to extended X-ray absorption fine structure analysis, the occurrence of U-Fe and U-U shells indicated that high effective removal of uranium was primarily inner-sphere coordination and then reductive co-precipitation at low pH. These observations provided the further understanding of uranium removal by magnetic materials in environmental remediation.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 21207092, 21577093)the Science and Technology Project of Shaoxing (No. 2014B70041)
文摘The magnetic iron oxide（Fe3O4） nanoparticles stabilized on the biochar were synthesized by fast pyrolysis of Fe（II）-loaded hydrophyte biomass under N2 conditions. The batch experiments showed that magnetic biochar presented a large removal capacity（54.35 mg/g）at pH 3.0 and 293 K. The reductive co-precipitation of U（VI） to U（IV） by magnetic biochar was demonstrated according to X-ray diffraction, X-ray photoelectron spectroscopy and X-ray absorption near edge structure analysis. According to extended X-ray absorption fine structure analysis, the occurrence of U-Fe and U-U shells indicated that high effective removal of uranium was primarily inner-sphere coordination and then reductive co-precipitation at low pH. These observations provided the further understanding of uranium removal by magnetic materials in environmental remediation.
