TY - JOUR
T1 - Efficient removal of uranium from aqueous solution by zero-valent iron nanoparticle and its graphene composite
AU - Li, Zi Jie
AU - Wang, Lin
AU - Yuan, Li Yong
AU - Xiao, Cheng Liang
AU - Mei, Lei
AU - Zheng, Li Rong
AU - Zhang, Jing
AU - Yang, Ju Hua
AU - Zhao, Yu Liang
AU - Zhu, Zhen Tai
AU - Chai, Zhi Fang
AU - Shi, Wei Qun
N1 - Funding Information:
This work was supported by National Natural Science Foundation of China (Grants 11205169 , 91326202 , 21261140335 ) and the “Strategic Priority Research program” of the Chinese Academy of Sciences (Grants. XDA030104 ). The financial support from the State Key Laboratory of NBC Protection for Civilian (No. SKLNB2014-12 ) is also acknowledged.
Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015/6/5
Y1 - 2015/6/5
N2 - 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 24ppm 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)=643ppm, and the saturation sorption of 8173mgU/g ZVI-nps was achieved at C0(U)=714ppm. 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 Fe2+ ions. The dissolution of Fe0 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.
AB - 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 24ppm 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)=643ppm, and the saturation sorption of 8173mgU/g ZVI-nps was achieved at C0(U)=714ppm. 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 Fe2+ ions. The dissolution of Fe0 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.
KW - Graphene composites
KW - Hydrolysis precipitation
KW - Reductive precipitation
KW - Uranium removal
KW - Zero-valent iron nanoparticles
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U2 - 10.1016/j.jhazmat.2015.02.028
DO - 10.1016/j.jhazmat.2015.02.028
M3 - Article
C2 - 25734531
AN - SCOPUS:84923346708
VL - 290
SP - 26
EP - 33
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
SN - 0304-3894
ER -