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.
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, University of South China, Hengyang, 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.
通讯机构：
[Li, Mi] U;Univ South China, Sch Environm & Safety Engn, Hengyang 421001, Peoples R China.
关键词：
Uranium;Tailings;Leaching;Gangue
摘要：
Uranium recovery from tailings is difficult because of the encapsulation of uranium by high content of gangue minerals. Uranium separation from gangue minerals has also been a key point in improving uranium extraction in the field of low-grade uranium resource recovery. This study proposed a high-efficiency alkali-pretreatment followed by acid leaching (two-step leaching) process for improving uranium extraction from uranium tailings. The main principle was to use a low concentration of alkaline solution to selectively comminute gangue minerals and to promote the formation of micropores in particles, providing a "path" for sulfuric acid to enter the interior of the uranium minerals. The effects of process parameters on uranium extraction and the changes in elemental composition, phase composition, morphology, and aperture of the tailings were investigated to show the mechanism of gangue comminution. Results showed that the uranium extraction percent without alkali pretreatment was only 63.91%, while it increased to 90.80% for the two-step leaching process under the same conditions. The low concentration of alkaline solution can selectively decompose gangue minerals, and dilute acid can then further reduce the degree of crystallinity of the silicates. Thus, a large number of mesopores in the tailings formed to improve the exposure ratio of uranium to the leaching agent. This new discovery may aid in the recovery of valuable metals from low-grade ore or tailings with high gangue content.
作者机构：
Key Laboratory of Radioactive Waste Treatment and Disposal, University of South China, Hengyang, 421001, China;[姚娅; 杨升; 杨蓉; 蒋天娇] School of Environmental Protection and Safety Engineering, University of South China, Hengyang, 421001, China;Wanma Group, Hangzhou, 310018, China;[李密; 张晓文] Key Laboratory of Radioactive Waste Treatment and Disposal, University of South China, Hengyang, 421001, China, School of Environmental Protection and Safety Engineering, University of South China, Hengyang, 421001, China;[易成] School of Environmental Protection and Safety Engineering, University of South China, Hengyang, 421001, China, Wanma Group, Hangzhou, 310018, China
关键词：
氧化铋;混凝土;线衰减系数;田口法
摘要：
将氧化铋以粉末形式添加到普通混凝土中,制备出绿色无污染且具有良好的g射线屏蔽性能的掺杂氧化铋的混凝土。相较于普通混凝土,氧化铋-混凝土的屏蔽性能及力学性能均得到改善。对比屏蔽性能实验结果及MCNP5(Monte Carlo N-Particle 5)模拟结果,二者相符很好,可以用MCNP5进行后期配合比设计优化。运用田口方法对水泥量、水胶比、氧化铋比例及砂率等进行优化设计。结果表明,对氧化铋-混凝土屏蔽能力影响最大的参数是氧化铋的加入量,其次为水泥量,水胶比及砂率的影响可忽略。
作者机构：
[张晓文; 李密; 张彪; 黄婧] School of Environment Protection and Safety Engineering, University of South China, Hengyang, 421001, China;[丁德馨; 叶勇军] Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China;[张晓文; 李密] Key Laboratory of Radioactive Waste Treatment and Disposal, University of South China, Hengyang, 421001, China
通讯机构：
Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, China
