Efficient removal of uranium from aqueous solution by zero-valent iron nanoparticle and its graphene composite.
Zero-valent iron nanoparticle (ZVI-np) and its graphene composites were prepared and applied in the removal of uranium under anoxic conditions. It was found that solutions containing 24 ppm U(VI) could be completely cleaned up by ZVI-nps, regardless of the presence of NaHCO3, humic acid, mimic groundwater constituents or the change of solution pH from 5 to 9, manifesting the promising potential of this reactive material in permeable reactive barrier (PRB) to remediate uranium-contaminated groundwater. In the measurement of maximum sorption capacity, removal efficiency of uranium kept at 100% until C0(U) = 643 ppm, and the saturation sorption of 8173 mg U/g ZVI-nps was achieved at C0(U) = 714 ppm. In addition, reaction mechanisms were clarified based on the results of SEM, XRD, XANES, and chemical leaching in (NH4)2CO3 solution. Partially reductive precipitation of U(VI) as U3O7 was prevalent when sufficient iron was available; nevertheless, hydrolysis precipitation of U(VI) on surface would be predominant as iron got insufficient, characterized by releases of Fe(2+) ions. The dissolution of Fe(0) cores was assigned to be the driving force of continuous formation of U(VI) (hydr)oxide. The incorporation of graphene supporting matrix was found to facilitate faster removal rate and higher U(VI) reduction ratio, thus benefitting the long-term immobilization of uranium in geochemical environment.
Key Laboratory of Nuclear Radiation and Nuclear Energy Technology and Key Laboratory For Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
Zi-Jie
ZJ
Li
Key Laboratory of Nuclear Radiation and Nuclear Energy Technology and Key Laboratory For Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
Lin
L
Wang
Key Laboratory of Nuclear Radiation and Nuclear Energy Technology and Key Laboratory For Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
Li-Yong
LY
Yuan
School of Radiological and Interdisciplinary Sciences (RAD-X), and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, China.
Cheng-Liang
CL
Xiao
Key Laboratory of Nuclear Radiation and Nuclear Energy Technology and Key Laboratory For Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
Lei
L
Mei
Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing100049, China.
Li-Rong
LR
Zheng
Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing100049, China.
Jing
J
Zhang
Key Laboratory of Nuclear Radiation and Nuclear Energy Technology and Key Laboratory For Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
Ju-Hua
JH
Yang
Key Laboratory of Nuclear Radiation and Nuclear Energy Technology and Key Laboratory For Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
Yu-Liang
YL
Zhao
State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
Zhen-Tai
ZT
Zhu
School of Radiological and Interdisciplinary Sciences (RAD-X), and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, China. Electronic address: zfchai@suda.edu.cn.
Zhi-Fang
ZF
Chai
Key Laboratory of Nuclear Radiation and Nuclear Energy Technology and Key Laboratory For Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China. Electronic address: shiwq@ihep.ac.cn.
Wei-Qun
WQ
Shi
D006108:Graphite / Q000737:chemistry*; D060587:Groundwater / Q000737:chemistry*; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D012996:Solutions; D014501:Uranium / Q000302:isolation & purification*; D014867:Water; D014875:Water Pollutants, Radioactive / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods; D014961:X-Ray Diffraction
D006812:Humic Substances; D007202:Indicators and Reagents; D012996:Solutions; D014875:Water Pollutants, Radioactive; D014867:Water; D014501:Uranium; D006108:Graphite; D007501:Iron
Graphene composites; Hydrolysis precipitation; Reductive precipitation; Uranium removal; Zero-valent iron nanoparticles