期刊：
FRONTIERS IN CHEMISTRY,2022年10:835959 ISSN：2296-2646
通讯作者：
Wu, Xiaoyan;Liu, Y;Wu, XY
作者机构：
[Yu, Shoufu; Li, Mi; Zhang, Qiucai; Lv, Chunxue; Wu, Xiaoyan; Shi, Keyou; Ye, Jian; Zhang, Xiaowen; Liu, Yong; Xie, Wenjie] Univ South China, Hengyang, Peoples R China.;[Li, Mi; Wu, Xiaoyan; Ye, Jian; Zhang, Xiaowen] Univ South China, Hengyang Key Lab Soil Contaminat Control & Remedi, Hengyang, Peoples R China.;[Li, Mi; Wu, Xiaoyan; Ye, Jian; Zhang, Xiaowen] Univ South China, Key Lab Radioact Waste Treatment & Disposal, Hengyang, Peoples R China.;[Zhang, Qiucai; Liu, Yong] Univ South China, Decommissioning Engn Technol Res Ctr Hunan Prov U, Hengyang, Peoples R China.
通讯机构：
[Liu, Y ; Wu, XY; Wu, XY ] U;Univ South China, Hengyang, Peoples R China.;Univ South China, Hengyang Key Lab Soil Contaminat Control & Remedi, Hengyang, Peoples R China.;Univ South China, Key Lab Radioact Waste Treatment & Disposal, Hengyang, Peoples R China.;Univ South China, Decommissioning Engn Technol Res Ctr Hunan Prov U, Hengyang, Peoples R China.
摘要：
Iron-based materials have attracted much attention in water treatment because of excellent ability to treat pollutants. In this study, self-made iron-carbon micro-electrolysis packing (IMP) was introduced to treat uranium-bearing wastewater (UBW). The effects of the IMP dosage, initial pH of solution and initial U(VI) concentration was investigated. The comparison of material adsorption performance and repeated desorption experiments were also accomplished under the optimum conditions. The mechanism of treating UBW by IMP was revealed by studying the change of IMP's surface properties characterized before and after adsorption by Scanning Electron Microscope (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Mossbauer spectra (MS). Research results demonstrated that IMP is suitable for the treatment of UBW with low concentration at acid condition (pH < 5). SEM results indicated that uranium was deposited on the surface of IMP in the form of tidy fine particles. The most important reason for uranium removal was determined as the reduction of soluble U(VI) to insoluble U(IV) by IMP. The advantages of IMP for UBW treatment were verified with rapidity, high efficiency, and durability. Therefore, IMP could be considered as a positive material for uranium removal from UBW.
摘要：
<jats:p> Goethite is a stable and widespread mineral present in soil with many uses, and it affects the transportation and immobilization of heavy metals in solution. Nanogoethite was synthesized by a chemical precipitation method and used to batch adsorb U(VI) in solution. Adsorption experiments were used to understand the role of nanogoethite in controlling the U(VI) adsorption behavior in soil. The morphology and the crystallinity of nanogoethite were characterized by scanning electron microscopy and wide-angle X-ray powder diffractometry, respectively. The results showed that the crystallinity of nanogoethite after the adsorption of uranium did not change, but small particles appeared on the surface of the scales. The surface area was determined from N<jats:sub>2</jats:sub> adsorption–desorption experiments using the Brunauer–Emmett–Teller to be 81.86 m<jats:sup>2</jats:sup>/g. The effects of factors such as the contact time, pH, adsorbent dosage, and the initial concentration of uranium on the adsorption of U(VI) were investigated. The experimental results showed that nanogoethite removed over 85% of the U(VI) in an aqueous 5.0 mg/L U(VI) solution at pH 4.0 and at 298 K. The pseudo-second-order model was used to simulate the adsorption process. The results show that chemisorption plays a major role in the adsorption process. The results of this study suggest that nanogoethite may play a significant role in controlling the migration and transfer of U(VI) in the soil, thus controlling the presence of U(VI) in soil. </jats:p>
摘要：
Uranium (U) contamination of soil has become a major concern with respect to its toxicity, accumulation in the food chain, and persistence in the environment. Anthropogenic activities like mining and processing of U ores has become pressing issues throughout the world. The aim of the work is to understand the chemical fractionation of U in polluted soil and the mechanism involved. U-free soils samples of eluvial (E), illuvial (B), and parent-material (C) horizons from a hydrometallurgical factory area were used. The experimental results showed that the U adsorption capacity decreased with depth, and its mobility in the upper soil is better than the lower. It was closely related to distribution coefficient (K-d), pH, organic-matter (OM), and carbonate content of soil horizons. The chemical fractionation of U was studied using the BCR sequential extraction scheme for soils after saturated adsorption. It was noted that the U reducible and oxidizable fraction in the E and B horizons can vertically transfer to the C horizon and occurs a significant rearrangement of U in different horizons. BET, SEM, XRD, and FT-IR analyses showed that different U distribution and migration in soil profile is mainly affected by specific surface area, soil particle size, mineral composition, and active groups. The XPS data further indicated that U (VI) is gradually converted to U (IV) with decreased depth and fixed in deeper soil becoming insoluble and immobile. It is the first step to investigate potential migration and plan U mining and milling area long-term management. (C) 2019 Published by Elsevier Ltd.
作者机构：
[彭莹; 张晓文; 李密; 张宇; 吴晓燕] College of Resources, Environment and Safety Engineering, University of South China, Hengyang;Hunan;421001, China;[彭莹; 张晓文; 李密; 张宇; 吴晓燕] Hunan;[彭莹; 张晓文; 李密; 张宇; 吴晓燕] 421001, China
作者机构：
[张利江; 黄倩文; 杨升] School of Resource & Environmental and Safety Engineering, University of South China, Hengyang, 421001, China;Key Laboratory of Radioactive Waste Treatment and Disposal, University of South China, Hengyang, 421001, China;[王亮] Hengyang Valin Steel Tube Co. Ltd., Hengyang, 421001, China;[张晓文; 李密; 吴晓燕] School of Resource & Environmental and Safety Engineering, University of South China, Hengyang, 421001, China, Key Laboratory of Radioactive Waste Treatment and Disposal, University of South China, Hengyang, 421001, China
通讯机构：
[Zhang, X.] S;School of Resource & Environmental and Safety Engineering, China
作者机构：
[Fangying Gao; Mi Li; Xiaowen Zhang; Shaoyan Lv; Xiaoyan Wu] School of Environmental and Safety Engineering, University of South China
会议名称：
2nd International Conference on Material Science,Energy and Environmental Engineering(MSEEE 2018)
会议时间：
2018-08-16
会议地点：
中国陕西西安
摘要：
A new method for treating U-containing wastewater and recovering of uranium simultaneously by electro-deposition was proposed. The complexity of adsorbent preparation and difficulty in uranium recover
通讯机构：
[Zhang, Xiaowen] U;Univ South China, Key Lab Radioact Waste Treatment & Disposal, Hengyang 421001, Hunan, Peoples R China.
关键词：
Uranium;α-FeOOH;Phosphate;Sorption;Mechanism
摘要：
AbstractGoethite is a stable and widespread mineral in soil, which affects the transportation and immobilization of heavy metals in soil. Here, the three-dimensional flower-like goethite (TDFLG) was synthesized by refluxing precipitation method. The modified three-dimensional flower-like goethite (MTDFLG) was prepared by NaH2PO4 with dipping method. The obtained samples were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, N2 adsorption–desorption (BET), and X-ray diffraction (XRD). SEM images showed that the modification of phosphate had no major changes on the morphology of the original sample and the morphology of MTDFLG after adsorbed U(VI) had clearly change. For the goethite and modified goethite, the BET-specific surface area was 229.96 and 203.17m2/g, respectively. Moreover, the effects of adsorption time, sorbent dose, solution pH, and initial uranium concentration on the uranium adsorption behaviors were investigated using the two materials as adsorbent for the treatment of uranium-containing wastewater. The results showed that MTDFLG had better adsorption capacity than TDFLG on uranium. The increase in uranium removal on MTDFLG was due to the formation of ternary surface complexes (≡FePO4UO2). TDFLG and MTDFLG followed the pseudo-second-order kinetic model and the Langmuir adsorption isotherm model, which indicated that uranium adsorption on TDFLG or MTDFLG is mainly based on chemisorption, and the maximum adsorption capacity of two adsorbents is 48.24 and 112.36mg/g, respectively.
