通讯机构：
Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, China
通讯机构：
[Ding, De-xin] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.
关键词：
Gold bearing high arsenic sulphide concentrate;Microwave roasting;Water content;Iodide/iodine leaching
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：
The endophyte Pseudomonas sp. XNN8 was separated from Typha orientalis which can secrete indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate deaminase and siderophores and has strong resistance to uranium it was then colonized in the Syngonium podophyllum; and the S. podophyllum-Pseudomonas sp. XNN8 symbiotic purification system (SPPSPS) for uranium-containing wastewater was constructed. Afterwards, the hydroponic experiments to remove uranium from uranium-containing wastewater by the SPPSPS were conducted. After 24 days of treatment, the uranium concentrations of the wastewater samples with uranium concentrations between 0.5 and 5.0 mg/L were lowered to below 0.05 mg/L. Furthermore, the uranium in the plants was assayed using Fourier transform infrared spectroscopy (FTIR) and extended X-ray absorption fine structure (EXAFS) spectroscopy. The Pseudomonas sp. XNN8 was found to generate substantial organic groups in the roots of the Syngonium podophyllum, which could improve the complexing capability of S. podophyllum for uranium. The uranium in the roots of S. podophyllum was found to be the uranyl phosphate (47.4 %) and uranyl acetate (52.6 %).
摘要：
The anaerobic microcosms amended with 30 mM bicarbonate and without bicarbonate were established, respectively, and the reduction of U(VI) in the microcosms by functionalized indigenous microbial communities was investigated. Results of the chemical extraction and XANES analysis showed that the proportions of U(IV) in the microcosms amended with bicarbonate were 10 % lower than without bicarbonate at day 46. The amount of Cellulomonadaceae, Desulfovibrionaceae, Peptococcaceae and Veillonellaceae amended with bicarbonate was lower than without bicarbonate, so the reduction of U(VI) was less. The experimental results show that the high concentration bicarbonate has a significantly inhibitory effect on the reduction of U(VI).
摘要：
This study aimed to evaluate the biological effects of gamma irradiation on zebrafish embryos. Different doses of gamma rays (0.01, 0.05, 0.1, 0.5 and 1 Gy) were used to irradiate zebrafish embryos at three developmental stages (stage 1, 6 h post-fertilization (hpf); stage 2, 12 hpf; stage three, 24 hpf), respectively. The survival, malformation and hatching rates of the zebrafish embryos were measured at the morphological endpoint of 96 hpf. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST) were assayed. Morphology analysis showed that gamma irradiation inhibited hatching and induced developmental toxicity in a dose-dependent manner. Interestingly, after irradiation the malformation rate changed not only in a dose-dependent manner but also in a developmental stage-dependent manner, indicating that the zebrafish embryos at stage 1 were more sensitive to gamma rays than those at other stages. Biochemical analysis showed that gamma irradiation modulated the activities of antioxidant enzymes in a dose-dependent manner. A linear relationship was found between GPx activity and irradiation dose in 0.1–1 Gy group, and GPx was a suitable biomarker for gamma irradiation in the dose range from 0.1 to 1 Gy. Furthermore, the activities of SOD, CAT, GR and GPx of the zebrafish embryos at stage 3 were found to be much higher than those at other stages, indicating that the zebrafish embryos at stage 3 had a greater ability to protect against gamma rays than those at other stages, and thus the activities of antioxidant enzymes changed in a developmental stage-dependent manner.
作者机构：
南华大学核资源工程学院,湖南衡阳421001;南华大学铀矿冶生物技术国防重点学科实验室,湖南衡阳421001;[杜康; 李广悦; 刁宁宁; 王永东] School of Nuclear Resources Engineering, University of South China, Hengyang, Hunan 421001, China, Key Discipline Laboratory for National Defense of Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, Hunan 421001, China
通讯机构：
[Li, G.-Y.] S;School of Nuclear Resources Engineering, China
摘要：
To verifying the feasibility of uranium recovery with fungal metabolic products in large-scale applications, column leaching and ion exchange of uranium was carried out. The uranium recovery reached 81.76 % in 14 days. The ion exchange curve for the leach solution obtained with the metabolic products of Aspergillus niger was in the shape of a wave. The elution curve was similar to that of leaching with H2SO4. The results indicate that leaching with the metabolic products of A. niger is a promising and environmentally friendly method for exploitation of low grade uranium ores in large-scale applications.
通讯机构：
[Ding, De-xin] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, 28 West Changsheng Rd, Hengyang 421001, Hunan, Peoples R China.
关键词：
In situ leaching;Groundwater;Bioreduction;U(VI);Anaerobic zone
摘要：
To determine whether the U(VI) in groundwater under anoxic conditions at a decommissioned in situ leaching (ISL) uranium mine could be bioreduced, groundwater samples containing suspended sediments were taken from the mine, experimental setup was fabricated, and the jar containing the groundwater in the setup was amended with ethanol and incubated under anoxic conditions. The variations of pH, chemical oxygen demand, nitrate, sulfate, U(VI), and dissolved oxygen (DO) concentrations were monitored during the incubation. U(VI) concentration dropped to 0.043 mg/L when the stimulated microorganisms were active, and it then increased to 0.835 mg/L within 10 days after the metabolism of the stimulated microorganisms was inhibited. The DO variation was observed in the amended jar during the incubation, and the metabolism of the stimulated microorganisms was found to affect the DO concentration. Firmicutes were found to be dominant in the sediments in the amended jar through the 16S rRNA pyrosequencing. The results indicate that it is possible to bioreduce U(VI) in the groundwater under anoxic conditions at the decommissioned ISL uranium mine by adding carbon source into it without removing the oxygen from it.
摘要：
An absorptive fungal strain for uranium adsorption which is named Q5, was isolated from the drainage of a uranium mine in South China. The morphological, physiological and phylogenetic characterizations of the strain Q5 were investigated. The results showed that, the strain Q5 identified as Penicillium funiculosum (99 % similarity in gene sequence). Furthermore, the adsorption performance of P. funiculosum was greatly improved by the mutational method that combined hydroxylamine hydrochloride and UV light. The results showed that the adsorption capacity of the mutated P. funiculosum for U(VI) was obviously better than the non-mutational one at pH 2.0–9.0.
