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.
摘要：
In this paper, the developmental toxicity and apoptosis in zebrafish (Danio rerio) embryos induced by 0.01, 0.05, and 0.10-Gy gamma-ray irradiation were investigated and verified by single cell gel electrophoresis, acridine orange staining, flow cytometry, transmission electron microscopy, digital gene expression sequencing, and Western blot analysis. DNA damage, deformity rates, and apoptosis of zebrafish embryos were found to increase significantly with the increase of irradiation dose, and survival and hatching rates significantly decreased when the irradiation dose exceeds 0.10 and 0.05 Gy, respectively. Exposure to 0.10-Gy gamma-ray irradiation resulted in the swelling of cell mitochondria of zebrafish embryos and changes in their intracellular vacuoles. mRNA and protein expression levels of Shh (sonic hedgehog 19 KDa) and Smo (smoothened 86 KDa) of Hh signaling pathway associated with the development of early embryos significantly increased with the increase of irradiation dose. Expression of the AKT (56 KDa) and PiK3r3 (55 KDa) genes, which are anti-apoptotic and involved with the PI3K/Akt signaling pathway, significantly decreased, while expression of the bada gene, which is pro-apoptotic, significantly increased. The results show that gamma-ray irradiations of 0.01 and 0.05 Gy can induce developmental toxicity and apoptosis in zebrafish embryos via Hh and PI3K/Akt signaling pathways, respectively.
摘要：
A greenhouse pot experiment was performed to investigate the enhancement of repeated applications of citric acid (CA), ethylenediamine disuccinic acid (EDDS), and Oxalic acid (OA) on phytoremediation of uranium (U) contaminated soil by Macleaya Cordata. The chelates followed the order CA > EDDS > OA in terms of the enhancement on uranium uptake by M. cordata. The repeated applications of the chelates were found to be more effective than the one time application at the equal dose as the U concentration of soil solution increased significantly from the 8th to 14th day. The repeated applications of 10 mmol kg(-1) CA promoted the solubilization of U in the U-contaminated soil by significantly decreasing the pH of soil solution, achieved the maximum U concentration of soil solution (1463.6 microg L(-1)), bioconcentration factors (BCFs, 11.4), bioaccumulation factors (BAFs, 21.4) and transfer factors (TFs, 1.9), which were 215.2, 5.7, 30.6 and 16.3 times as compared with the control group, respectively. The three applied chelates significantly affected the activities of the antioxidant enzymes in the leaves. Repeated applications of CA further enhanced the activities of the antioxidant enzymes in the leaves of M. cordata as compared with the control, EDDS and OA, mitigated the oxidative stress induced by uranium and chelates, and maximized the enhancement on the uranium uptake, which will be beneficial for the enhancement on the phytoremediation of uranium contaminated soil by U hyperaccumulating plants. These results indicated that the phytoavailability of uranium in soil solution as well as the accumulation of U by M. cordata were both significantly increased after repeated applications of CA, and that the repeated applications of 10 mmol kg(-1) CA increased the activities of the antioxidant enzymes and promoted U accumulation by M. cordata. The study provided an environmentally friendly alternative for the enhancement on the phytoremediation of uranium contaminated soil using M. cordata.
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.
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：
Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, China
期刊：
American Journal of Biochemistry and Biotechnology,2018年14(2):145-153 ISSN：1553-3468
通讯作者：
Ding, De-Xin(dingdxzzz@163.com)
作者机构：
[Cao, Yun-Chang; Hu, Nan; Wang, Yong-Dong; Li, Gaung-Yue; Ding, De-Xin] Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, 28 West Changsheng Rd, Hengyang;Hunan;421001, China;[Wen, Hong-Bo] Department of Biochemistry and Molecular Biology, School of Pharmaceutical and Biological Science, University of South China, 28 West Changsheng Rd, Hengyang;[Cao, Yun-Chang; Wen, Hong-Bo; Hu, Nan; Wang, Yong-Dong; Li, Gaung-Yue; Ding, De-Xin] Hunan
通讯机构：
[Ding, D.-X.] K;Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, 28 West Changsheng Rd, Hengyang, Hunan, China
作者机构：
[李殿鑫; 胡南; 黄超; 丁德馨; 李广悦; 王永东] Key Discipline Laboratory for National Defence for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang;Hunan;421001, China;Hunan Province Key Laboratory of Green Development Technology for Extremely Low Grade Uranium Resources, University of South China, Hengyang;[李殿鑫; 胡南; 黄超; 丁德馨; 李广悦; 王永东] Hunan
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
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.
作者机构：
[李广悦; 刘玉龙; 丁德馨; 王有团; 胡南] Key Discipline Laboratory for National Defence for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China;[马亮; 刘玉龙] CGNPC Uranium Resources Co., Ltd., Beijing, 100029, China
通讯机构：
Key Discipline Laboratory for National Defence for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, China
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).
