作者机构：
[陈璐] School of Nuclear Resources Engineering, University of South China, Hengyang, Hunan 421001, China;[谭云亮; 赵同彬; 臧传伟; 于凤海] College of Resources and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
通讯机构：
School of Nuclear Resources Engineering, University of South China, China
通讯机构：
[Tan, Kaixuan] U;Univ South China, Sch Nucl Resources Engn, Hengyang 421001, Peoples R China.
关键词：
Complex surfactant;Leaching kinetics;Resin adsorption and elution;Low permeable sandstone uranium deposit;In-situ leaching of uranium mining
摘要：
Applications of a complex surfactant developed in-house to in-situ leaching of low permeable sandstone uranium deposits are described based on results from agitation leaching, column leaching, resin adsorption, and elution experiments using uranium containing solution from the in-situ leaching site. The results of agitation leaching experiments show that adding surfactant with different concentrations into leaching solution improves the leaching rate of uranium. The maximum leaching rate of uranium from agitation leaching reached 92.6% at an added surfactant concentration of 10 mg/l. Result of column leaching experiment shows that adding surfactant with varying concentrations into leaching solutions increased the permeability coefficient of ore-bearing layer by 42.7-86.8%. The leaching rate of uranium from column leaching increased by 58.0% and reached 85.8%. The result of kinetic analysis shows that for the extraction of uranium controlled by diffusion without surfactant the apparent rate constant 0.0023/d changed to 0.0077/d for the extraction with surfactant controlled by both diffusion and surface chemical reactions. Results from resin adsorption and elution experiments show that there was no influence on resin adsorption and elution of uranium with an addition of 50 mg/l surfactant to production solution from in-situ leaching. The adsorption curve, sorption capacity of resin, recycling of resin remained the same as without adding any surfactant. Introducing complex surfactant to leaching solution increased the peak concentration of uranium in eluents, reduced the residual uranium content in resin, and promoted the elution efficiency. The method of using a complex surfactant for in-situ leaching is useful for low permeable sandstone uranium deposits. (C) 2014 Elsevier B.V. All rights reserved.
摘要：
In order to develop an effective and economical method for removing U(VI) from the low concentration radioactive wastewater with the U(VI) concentration of less than 1 mg L<sup>-1</sup>, the biomass of Aspergillus niger was prepared and modified with ethylenediamine, and the biosorption of uranium from the low concentration radioactive wastewater by the unmodified and the modified biomasses was investigated in a batch system. The modified biomass exhibited the adsorption efficiency of 99.25 % for uranium under the optimum conditions that pH was 5.0, the contact time was 150 min, and the biosorbent dose was 0.2 g L<sup>-1</sup>. The adsorption fitted well to Langmuir isotherm, and the maximum sorption capacity of the modified biomass for U(VI) was determined to be 6.789 mg g<sup>-1</sup> which increased by 36.45 % compared with the unmodified biomass. The adsorption kinetics was better depicted by pseudo-second-order kinetic model. The Gibbs free energy change (ΔG <sup>0</sup>), enthalpy change (ΔH <sup>0</sup>), and entropy change (ΔS <sup>0</sup>) showed that the process of U(VI) adsorption was spontaneous, endothermic, and feasible. The changes in the groups, morphology, and the presence of U(VI) on the surface of the adsorbents which were characterized by FT-IR, SEM, and EDS, demonstrated that the U(VI) was successfully adsorbed onto the modified biomass. Moreover, the UO<inf>2</inf> <sup>2+</sup> absorbed on the modified biomass can be released by 0.1 mol L<sup>-1</sup> HNO<inf>3</inf> with high desorption efficiency of 99.21 %. The results show that the modified biomass can remove U(VI) from low concentration radioactive wastewater more effectively than the unmodified biomass.
作者机构：
[周新尧; 李咏梅; 谭凯旋; 李春光; 周泉宇] School of Nuclear Resources Engineering, University of South China, Hengyang, China;[刘泽华] School of Urban Construction, University of South China, Hengyang, China
通讯机构：
School of Nuclear Resources Engineering, University of South China, Hengyang, China
作者机构：
[谢水波; 周帅; 王文涛; 唐振平; 马华龙; 高媛媛] Hunan Provincial Key Laboratory of Pollution Control and Resources Technology, University of South China, Hengyang 421001, China;[谢水波] Key Discipline Lab of National Defence for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China
通讯机构：
Hunan Provincial Key Laboratory of Pollution Control and Resources Technology, University of South China, China
摘要：
In order to investigate the mechanism of extracellular polymeric substances (EPS) influencing sludge characteristics, variations of extractable EPS from municipal sewage sludge by acid/alkaline pretreatment and gamma-ray irradiation were studied. The changes in constituents of EPS were analyzed by UV-vis spectra and SEM images. The effects of alkaline pretreatment and gamma-ray irradiation on the functional groups in EPS were investigated by Fourier transform infrared (FTIR) spectrometer. Results showed that the extractable EPS increased clearly with increasing irradiation dose from 0 to 15 kGy. UV-vis spectra indicated that a new absorption band from 240 nm to 300 nm existed in all irradiated samples, apart from acid condition. The results of FTIR spectroscopic analysis indicated that, irradiation influenced major functional groups in EPS, such as protein and polysaccharide, and these effects were clearer under alkaline condition. SEM images provided that after alkaline hydrolysis, gamma-ray irradiation was more effective in resulting in the sludge flocs and cells broken, compared with acid pretreatment (pH 2.50). (c) 2013 Published by Elsevier Ltd.
作者机构：
[Kaixuan TAN; Yanshi XIE; Yang HU; Chunguang LI; Zhaozhao WANG; Fei YANG] School of Nuclear Resource Engineering, University of South China, Hengyang 421001 China
通讯机构：
[Kaixuan TAN] S;School of Nuclear Resource Engineering, University of South China, Hengyang 421001 China
会议名称：
The 14th Quadrennial Interbational Association on the Genesis of Ore Deposium Symposium(第十四届国际矿床成因协会大会)
会议时间：
2014-08-19
会议地点：
昆明
会议论文集名称：
The 14th Quadrennial Interbational Association on the Genesis of Ore Deposium Symposium(第十四届国际矿床成因协会大会)论文集
摘要：
<正>Sandstone type uranium deposits(STUD)were an important uranium resource in the world.The exploration and exploitation of leachable STUD act an important role in world uranium supply with the develo
作者机构：
[Chen L.; Huang W.; Tan K.X.; Wang Z.Q.; Xie Y.S.; Hu Y.] School of Nuclear Resources Engineering, University of South China, Hengyang, Hunan, 421001, China;[Li Y.F.] HydroChina Zhongnan Engineering Corporation, Changsha, Hunan, 410014, China
会议名称：
3rd International Conference on Energy and Environmental Protection, ICEEP 2014
会议时间：
26 April 2014 through 28 April 2014
关键词：
Chemical speciation of uranium;In-situ leaching;Sandstone uranium deposit
