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：
环境工程专业的教育强调知识的应用性,注重培养学生分析问题、解决问题的能力。为促进工程教育的国际互认,环境工程专业工程教育认证势在必行。南华大学环境专业是在原核工业第六研究所通风辐射防护室等基础上发展而来的,特色鲜明。近年,南华大学环境工程专业基于 OBE（Outcome based education）教育模式,紧紧围绕学校"一基三实"中强调的"把人才培养做实","把服务社会做实"的学校发展思路,在培养目标分解、理论课程体系和实践教学改革、学生创新能力培养、评估体系完善和高素质教师队伍建设等方面进行了一系列的改革与尝试,取得了良好效果。
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
