摘要：
Uranium-contaminated wastewater associated with uranium (U) mining and processing inevitably releases into soil environment. In order to assess the risk of U wastewater contamination to groundwater through percolation, U adsorption and transport behavior in a typical red soil in South China was investigated through batch adsorption and column experiments, and initial pH and carbonate concentration were considered of the high-sulfate background electrolyte solution. Results demonstrated that U adsorption isotherms followed the Freundlich model. The adsorption of U to red soil significantly decreased with the decrease of the initial pH from 7 to 3 in the absence of carbonate, protonation-deprotonation reactions controlled the adsorption capacity, and lnCs had a linear relationship with the equilibrium pH (pHeq). In the presence of carbonate, the adsorption was much greater than that in the absence of carbonate owing to the pHeq values buffered by carbonate, but the adsorption decreased with the increase of the carbonate concentration from 3.5 to 6.5 mM. Additionally, the breakthrough curves (BTCs) obtained by column experiments showed that large numbers of H(+) and CO3(2-) competed with the U species for adsorption sites, which resulted in BTC overshoot (C/C0 > 1). Numerical simulation results indicated that the BTCs at initial pH 4 and 5 could be well simulated by two-site chemical non-equilibrium model (CNEM), whereas the BTCs of varying initial carbonate concentrations were suitable for one-site CNEM. The fractions of equilibrium adsorption sites (f) seemed to correlate with the fractions of positively charged complexes of U species in solution. The values of partition coefficients (kd(')) were lower than those measured in batch adsorption experiments, but they had the same variation trend. The values of first-order rate coefficient (omega) for all BTCs were low, representing a relatively slow equilibrium between U in the liquid and solid phases. In conclusion, the mobility of U in the red soil increased with the decrease of the initial pH and with the increase of the initial carbonate concentrations.
作者机构：
[Li Feng; Zou Chao; Dai Zhong-ran; Ding De-xin; Li Guang-yue; Hu Nan; Wang Yong-dong; Cui Yue-ting; Sun Jing; Sha Yin-hua; Zhang Hui] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Heng Yang 421001, Hunan, Peoples R China.
通讯机构：
[Wang Yong-dong] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Heng Yang 421001, Hunan, Peoples R China.
摘要：
Aspergillus niger (A. niger) and Syngonium podophyllum (S. podophyllum) have been used for wastewater treatment, and have exhibited a promising application in recent years. To determine the effects of A. niger on uranium enrichment and uranium stress antagonism of S. podophyllum, the S. podophyllum-A. niger combined system was established, and hydroponic remediation experiments were carried out with uranium-containing wastewater. The results revealed that the bioaugmentation of A. niger could increase the biomass of S. podophyllum by 5-7%, reverse the process of U(VI) reduction induced by S. podophyllum, and increase the bioconcentration factor (BCF) and translocation factor (TF) of S. podophyllum to uranium by 35-41 and 0.01-0.06, respectively, thereby improving the reduction of uranium in wastewater. Moreover, A. niger could promote the cell wall immobilization and the subcellular compartmentalization of uranium in the root of S. podophyllum, reduce the phytotoxicity of uranium entering root cells, and inhibit the calcium efflux from root cells, thereby withdrawing the stress of uranium on S. podophyllum. (C) 2019 Published by Elsevier Ltd.
作者机构：
[李广悦; 王浩; 丁德馨; 李峰; 喻清; 胡南] Key Discipline Laboratory of Defense Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China;[喻清] School of Resources and Safety Engineering, Central South University, Changsha, 410083, China
通讯机构：
Key Discipline Laboratory of Defense Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, China
摘要：
A new technology for enhancing microwave roasting of gold bearing high arsenic sulphide concentrate with various water contents was proposed. The influence of water content and roasting time on microwave roasting of gold concentrate was investigated, and the mechanism of microwave roasting of gold bearing high arsenic sulphide concentrate with various water contents was analyzed. The results show that the removal rate of sulfur and iodide/iodine leaching rate of gold are mainly dependent on water content. The removal rate of sulfur and the leaching rate of gold reaches 87.95% and 75.08%, respectively, under the conditions of water content of 9% with microwave roasting for 30 min. After the dried concentrate sample and the wetted concentrate sample with 9% water content were roasted in the microwave oven for 60 min, the latter was found by SEM to be more porous than former, its specific surface area was found to increase from 25.6 to 32.7 m(2)/g. (C) 2017 Elsevier B.V. All rights reserved.
摘要：
选用富含铁的火山岩型铀矿石,对其进行微波预处理,然后,在常温常压下进行搅拌浸出.考察微波预处理浸出铀的效果,并比较微波预处理前后矿物粒度、硫酸浓度、液固比、搅拌时间对浸出率的影响.结果表明：微波预处理后,硫酸的消耗量未增加,浸出所需时间缩短,矿物粒度较大时仍能获得相对较好的浸出率;与对照组相比,铀浸出率有所提高,微波预处理该铀矿石可行.微波预处理后,该铀矿石最佳的浸出工艺条件为矿物粒度-150μm、硫酸浓度20 g/L、液固比3L/kg、搅拌时间9 h.
作者机构：
[杨雨山; 喻清; 丁德馨] School of Resources and Safety Engineering, Central South University, Changsha, 410083, China;[王浩; 李峰; 喻清; 丁德馨; 杨雨山; 胡南] Key Discipline Laboratory of Defense Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China
通讯机构：
School of Resources and Safety Engineering, Central South University, Changsha, China
作者机构：
[李峰; 陈伟; 丁德馨] School of Nuclear Resource Engineering, University of South China, Hengyang, China;[李峰; 陈伟; 胡南; 丁德馨] Key Discipline Laboratory for National Defence for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, China
通讯机构：
School of Nuclear Resource Engineering, University of South China, Hengyang, China
关键词：
含金硫精矿;金;微波焙烧;预处理;浸出率;表面形貌
摘要：
对难浸含金硫精矿进行微波焙烧,考察微波功率、矿量（即样品质量）和焙烧时间对样品质量损失率和浸出率的影响。结果表明:当微波功率为16 k W、焙烧时间为50 min、矿量为900 g时,样品质量损失率可达28.12%,浸出率可达71.56%,较原矿直接碘化浸出率（9.82%）有了大幅提高。利用XRD和SEM技术分析焙烧前后样品的成分和表面形貌,微波焙烧后的样品较原矿更为松散、多孔,更利于浸出。
作者机构：
[李峰; 胡南; 彭志成; 陈伟; 丁德馨] Key Discipline Lab. for National Defence for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China;[李峰; 彭志成; 陈伟; 丁德馨] School of Nuclear Resource Engineering, University of South China, Hengyang 421001, China
通讯机构：
Key Discipline Lab. for National Defence for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, China
作者机构：
[丁德馨; 李峰] Key Discipline Lab. for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China;[钟永明] School of Environment Protection and Safety Engineering, University of South China, Hengyang 421001, China;[叶勇军] Key Discipline Lab. for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China <&wdkj&> School of Environment Protection and Safety Engineering, University of South China, Hengyang 421001, China
通讯机构：
Key Discipline Lab. for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, China
作者机构：
[叶勇军; 李广悦; 李峰; 宋键斌; 丁德馨] Key Discipline Lab. for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, Hunan 421001, China
通讯机构：
Key Discipline Lab. for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, China
