Hyphae and organic acids of Aspergillus Niger promote uranium recovery by destroying the ore surface and increasing the porosity and permeability of ores
作者：
Wang, Yongdong;Wang, Jinhua;Ding, Dexin;Li, Guangyue;Sun, Jing;...
期刊：
Nuclear Engineering and Technology ,2024年56(5):1880-1886 ISSN：1738-5733
通讯作者：
Wang, YD
作者机构：
[Ding, Dexin; Zhang, Hui; Wang, Jinhua; Li, Guangyue; Dai, Zhongran; Li, Feng; Hu, Nan; Sun, Jing; Ma, Jianhong; Ding, Yang; Wang, Yongdong] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Wang, YD ] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Hengyang 421001, Hunan, Peoples R China.
关键词：
Aspergillus Nige;Bioleaching;Uranium ore;Exfoliation;Proton exchange
摘要：
To elucidate the mechanism of damage caused by hyphae and organic acids produced by Aspergillus Niger on the surface and internal structure of uranium ore, direct uranium leaching, indirect uranium leaching and semi-direct uranium leaching were conducted, and the surface morphology, strength, mineral crystallinity, porosity, and permeability of the ore were analyzed. The results demonstrated that the combination of biomechanical forces exerted by hyphae and the complexation effects of organic acids led to the dissolution of SiO2 and other substances on the surface of ore, resulting in exfoliation from the exterior to the interior, thereby promoting uranium recovery. Furthermore, the proton exchange involving H+ and the complexation of organic acids resulted in the dissolution of cations within the ore, causing destruction to the crystal lattice structure of minerals and increasing the porosity and permeability inside the ore. The dominant factor contributing to ore damage during recovery was organic acids. © 2023 Korean Nuclear Society
语种：
英文
展开
Unraveling response mechanism of electron transport mechanism to uranium-exposure in Bacillus sp. X02
作者：
Yi, Haitao;Zou, Chao;Ding, Dexin;Li, Guangyue;Wang, Jinhua;...
期刊：
Journal of Water Process Engineering ,2024年58:104796 ISSN：2214-7144
通讯作者：
Wang, YD
作者机构：
[Ding, Dexin; Zou, Chao; Li, Guangyue; Wang, Jinhua; Li, Aishu; Yi, Haitao; Wang, Yongdong] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Heng Yang 421001, Hunan, Peoples R China.
通讯机构：
[Wang, YD ] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Heng Yang 421001, Hunan, Peoples R China.
关键词：
Electron transfer mechanism;U(VI) bioreduction;Cytochrome c;Oxidative phosphorylation;Bacillus sp. X02
摘要：
With the development of the uranium mining industry, the remediation of uranium pollution is an urgent environmental problem to be solved. Bioreduction is currently recognized as a U(VI) bioremediation method with good application prospects. However, inadequate reporting of uranium-reducing bacteria and low bioreduction efficiency are the main reasons limiting the application of the bioreduction method. In this paper, we isolated an efficient uranium-reducing bacterium, Bacillus sp. X02, explored the effect of U(VI) on bioreduction efficiency through electron transport mechanisms. The results showed that the maximum removal and reduction rate were 98.35 % and 62.43 %, respectively. Further studies revealed that the efficiency of extracellular electron transport of Bacillus sp. X02 was enhanced under U(VI) exposure. But uranium stress down-regulated the expression of F-type ATPase, Cytochrome c reductase ISP, Cytochrome c oxidase, and Cytochrome bd complex, inhibited the processes of complex III, complex IV, and ATP synthesis in the oxidative phosphorylation electron transport pathway, decreasing the electron transfer and U(VI) reduction capacity of Bacillus sp. X02 ultimately. This work proposed a new electron transfer pathway for U(VI) bioreduction and provided new insights into the effect of uranium on bioreduction efficiency. © 2024 Elsevier Ltd
语种：
英文
展开
Experimental study of remediation of wastewater with low concentrations of uranium using Syngonium podophyllum-endophyte symbiotic systems
作者：
Zhou, T. H.;He, L.;Deng, Q. W.;Ding, D. X.;Wang, Y. D.;...
期刊：
International Journal of Environmental Science and Technology ,2023年20(2):1769-1778 ISSN：1735-1472
通讯作者：
Deng, QW
作者机构：
[Zhou, T. H.; He, L.; Chen, Y. X.; Wang, Y. D.; Ding, D. X.; Deng, QW; Deng, Q. W.] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Hunan, Peoples R China.;[Zhou, T. H.; He, L.; Chen, Y. X.; Deng, QW; Deng, Q. W.] Univ South China, Hengyang Key Lab Soil Pollut Control & Remediat, Hengyang 421001, Hunan, Peoples R China.;[Zhou, T. H.; He, L.; Chen, Y. X.; Wang, Y. D.; Ding, D. X.; Deng, QW; Deng, Q. W.] Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.;[He, L.] China Bluestar Chonfar Engn & Technol Co Ltd, Changsha 410007, Hunan, Peoples R China.
通讯机构：
[Deng, QW ] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Hunan, Peoples R China.;Univ South China, Hengyang Key Lab Soil Pollut Control & Remediat, Hengyang 421001, Hunan, Peoples R China.;Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.
关键词：
Bacteria;Fourier transform infrared spectroscopy;Pollution;Wastewater treatment;Binding effects;Endophyte;Integrated remediation;Low concentrations;Podophyllum;Symbiotics;Syngonium podophyllum;Typha orientalis;Urania and wastewater;Uranium concentration;Uranium;bacterium;colonization;endophyte;experimental study;monocotyledon;uranium;wastewater treatment
摘要：
Treatment of uranium-containing wastewater using a plant–microbe symbiotic system appears promising. To find a viable method for wastewater treatment containing low concentrations of uranium (5mg/L or lower), a Syngonium(S) podophyllum-endophyte symbiotic system was designed and hydroponic remediation experiments were conducted. After 25days of treatment, the uranium concentrations of the wastewater samples with uranium concentrations between 0.5 and 2.0mg/L were lowered to below 0.05mg/L. Analysis of the concentration data and transfer factors (TF) of uranium in plant roots, stems and leaves showed that S. podophyllum concentrated uranium mainly through its roots. Furthermore, Fourier transform infrared spectroscopy (FTIR) showed that the roots of S. podophyllum colonized by Bacteria XNN8 (separated from Typha orientalis, beef extract peptone medium, bacteria numbered eight) produced more sugars and –OH than that by the uncolonized S. podophyllum, hence promoting the binding effect of –OH on uranium in plants. Colonization by actinomycetes XNG3 (separated from Typha orientalis, modified Gao’s No. 1 medium, actinomycetes numbered three) might either increase the content of C = O, COO–, C–O and C–N in the roots of S. podophyllum or strengthen the binding effect of these functional groups with uranium. © 2022, The Author(s) under exclusive licence to Iranian Society of Environmentalists (IRSEN) and Science and Research Branch, Islamic Azad University.
语种：
英文
展开
Coupled variations of dissolved organic matter distribution and iron (oxyhydr)oxides transformation: Effects on the kinetics of uranium adsorption and desorption
作者：
Ding, Yang;Huang, Xixian;Zhang, Hui;Ma, Jianhong;Li, Feng;...
期刊：
Journal of Hazardous Materials ,2022年436:129298 ISSN：0304-3894
通讯作者：
Xixian Huang
作者机构：
[Ding, Dexin; Zhang, Hui; Dai, Zhongran; Li, Feng; Hu, Nan; Ma, Jianhong; Ding, Yang; Wang, Yongdong] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Hengyang 421001, Peoples R China.;[Ding, Dexin; Zhang, Hui; Dai, Zhongran; Li, Feng; Hu, Nan; Ma, Jianhong; Ding, Yang; Wang, Yongdong; Zeng, Qingyi; Huang, Xixian] Univ South China, Sch Resource & Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.;[Huang, Xixian] South China Univ Technol, Guangdong Prov Key Lab Solid Wastes Pollut Control, Guangzhou 510006, Guangdong, Peoples R China.
通讯机构：
[Xixian Huang] S;School of Resource & Environment and Safety Engineering, University of South China, Hengyang, Hunan 421001, PR China<&wdkj&>Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong 510006, PR China
关键词：
Adsorption;Biogeochemistry;Desorption;High resolution transmission electron microscopy;Kinetics;Mass spectrometry;Organic compounds;Soils;Uranium;Adsorption and desorptions;Contaminant behavior;Dissolved organic matter molecule;Dissolved organic matters;Dynamic variations;Fe (oxyhydr)oxides;High-resolution transmission electron microscopy;Orbitrap mass spectrometries;Transformation effects;Uranium adsorption;Molecules;dissolved organic matter;ferric hydroxide;iron oxide;polyphenol derivative;uranium;2,5 dimethoxy 4 methylamphetamine;dissolved organic matter;ferric ion;iron;mineral;oxide;adsorption;dissolved organic matter;experimental study;goethite;lepidocrocite;molecular analysis;reaction kinetics;transformation;uranium;adsorption kinetics;Article;chemical structure;controlled study;desorption;high resolution transmission electron microscopy;mass spectrometry;soil;adsorption;chemistry;kinetics;oxidation reduction reaction;2,5-Dimethoxy-4-Methylamphetamine;Adsorption;Dissolved Organic Matter;Ferric Compounds;Iron;Kinetics;Minerals;Oxidation-Reduction;Oxides;Soil;Uranium
摘要：
The interactions between dissolved organic matter (DOM) molecules and minerals play significant roles in affecting the fate of carbon and contaminants in soil environment. However, the mechanisms controlling the variations of DOM molecules distribution during the transformation of Fe (oxyhydr)oxides, and the effects of these variations on contaminant behaviors are still largely unknown. In this study, the dynamic variations of DOM properties and distributions, and the kinetics of uranium adsorption on and desorption from Fe (oxyhydr)oxides during the transformation were investigated, employing a combination of Orbitrap mass spectrometry (MS), high-resolution transmission electron microscopy (HR-TEM), and kinetic experiments. Orbitrap MS results indicated that aliphatic molecules and phenolic and polyphenolic molecules with lower O/C values were preferentially released to solution. HR-TEM results indicated that the coprecipitated DOM molecules by ferrihydrite were mainly released to solution rather than sorbed on the newly formed lepidocrocite or goethite during the transformation. Furthermore, the stirred-flow experiment results suggested that soil DOM significantly reduced the adsorption of uranium on, and accelerated the release of uranium from Fe (oxyhydr)oxides, which was ascribed to the changed distribution of DOM molecules and the structure and composition of Fe (oxyhydr)oxides. Our results contribute to predicting contaminant behaviors in soils. © 2022 Elsevier B.V.
语种：
英文
展开
Efficient removal of U(VI) in acidic environment with spent coffee grounds derived hydrogel
作者：
Ma, Jianhong;Zhang, Min;Zhang, Hui;Wang, Yongdong;Li, Feng;...
期刊：
Journal of Hazardous Materials ,2022年426:127786 ISSN：0304-3894
通讯作者：
Ding, DX
作者机构：
[Ding, Dexin; Zhang, Hui; Dai, Zhongran; Hu, Nan; Ma, Jianhong; Ding, Yang; Ding, DX] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;[Li, Feng; Wang, Yongdong; Zhang, Min] Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Ding, DX ] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.
关键词：
Acrylic monomers;Groundwater;Sorption;Acidic environment;Anti-interference;Humic-like substances;Macroporous;Performance;Poly(acrylic acid);Poly(acrylic acid) gels;Removal efficiencies;Sorption capacities;Spent coffee grounds;Hydrogels;uranium;adsorption;coffee;humic substance;hydrogel;pH;Adsorption;Coffee;Humic Substances;Hydrogels;Hydrogen-Ion Concentration;Uranium
摘要：
In this study, humic-like substances (HLSs) was extracted from spent coffee grounds (SCGs), and it together with poly acrylic acid (PAA), was used for the first time to synthesize hydrogel material, namely HLSs/PAA gel, by one-step radical polymerization. Its maximum theoretical sorption capacity toward U(VI) at pH 3.00 was 661.01 mg/g, and it could decrease the concentration of U(VI) in acidic actual groundwater from 0.2537 to 0.0003 mg/L, showing that the gel had excellent U(VI) removal efficiency in acidic environment. The SEM characterization of HLSs/PAA gel showed that its macroporous network structure maintained well after the sorption process, indicating that the gel had excellent acid-resistant property. Moreover, the gel exhibited excellent anti-interference performance in the interfering ions effect experiment. The gel integrates the merits of excellent U(VI) sorption properties, stability and anti-interference performance in acidic environment, and has promising application prospects in the remediation of acidic uranium wastewater. © 2021 Elsevier B.V.
语种：
英文
展开
Field Tests of the Phytoremediation of Uranium Tailings by Macleaya cordata (Willd.) R. Br.
作者：
He, Liu;Deng, Qinwen;Ding, Dexin;Wang, Yongdong;Wang, Fan
期刊：
ENVIRONMENTAL ENGINEERING SCIENCE ,2021年38(7):654-661 ISSN：1092-8758
通讯作者：
Deng, Qinwen(dengqw@usc.edu.cn)
作者机构：
[Ding, Dexin; He, Liu; Deng, Qinwen; Wang, Yongdong] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;[He, Liu; Deng, Qinwen; Wang, Fan] Univ South China, Hengyang Key Lab Soil Pollut Control & Remediat, Hengyang, Peoples R China.;[Ding, Dexin; He, Liu; Deng, Qinwen; Wang, Fan; Wang, Yongdong] Univ South China, Sch Resources Environm & Safety Engn, Hengyang, Peoples R China.
通讯机构：
[Qinwen Deng] K;Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, P.R. China. Hengyang Key Laboratory of Soil Pollution Control and Remediation, University of South China, Hengyang, P.R. China. School of Resources, Environment and Safety Engineering, University of South China, Hengyang, P.R. China.
关键词：
Macleaya cordata (Willd.) R. Br.;phytoremediation;uranium tailings
摘要：
The goal of this research is phytoremediation of uranium-contaminated soil. In the preliminary investigation, Macleaya cordata (Willd.) R. Br. was found to grow in abundance around uranium tailings. Afterward, the field tests to remove uranium from the contaminated soil by the M. cordata (Willd.) R. Br. were conducted. After 3 years of treatment, the contents of uranium in the shallow, middle, and deep layers decreased by 51.2%, 16.6%, and 90.3%, respectively, indicating the transfer of uranium from the tailings. The content of uranium in the roots, stems, and leaves of M. cordata that had been planted for 3 years was significantly higher than that in the first year, indicating the transfer of uranium to M. cordata (The uranium content of the part of M. cordata underground is 1.870 ± 0.288 mg/kg and the content in the aboveground part is 79.815 ± 0.911 mg/kg after 3 years). The results of Mi-Seq indicated that microbial communities were exposed to variations and that microbes, such as Bacillus, Lactococcus, Nitrosomonadaceae, and Roseiflexus, were involved in the remediation of uranium-contaminated soil, demonstrating that the reduced uranium content in the tailings is a result of the joint action by plants and microbes. An infrared analysis indicated that the -OH and COO- groups are the main functional groups in M. cordata involved in the bioconcentration of uranium. Moreover, as time advances, the uranium in the tailings was readily concentrated by the plant, demonstrating that the remediation of radioactive contamination by M. cordata is viable. © Copyright 2021, Mary Ann Liebert, Inc., publishers 2021.
语种：
英文
展开
Sporosarcina pasteurii诱导碳酸盐-铀共沉淀修复低浓度铀废水的试验研究
作者：
胡南;陈雪;张辉;李艾书;李广悦;...
期刊：
化工学报 ,2021年72(10):5354-5361 ISSN：0438-1157
通讯作者：
Ding, Dexin(dingdxizzz@163.com)
作者机构：
[胡南; 陈雪; 张辉; 李艾书; 李广悦; 王永东; 丁德馨] Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang;421001, China;[胡南; 陈雪; 张辉; 李艾书; 李广悦; 王永东; 丁德馨] 421001, China
关键词：
铀污染;生物修复;脲酶;碳酸盐-铀共沉淀
摘要：
对有钙源条件下Sporosarcina pasteurii诱导碳酸盐-铀共沉淀修复低浓度铀废水的性能开展了试验研究。试验结果表明,该细菌能分泌脲酶水解尿素诱导产生方解石并促使其与铀发生共沉淀,使废水中铀的去除率达到95.38%;该细菌能够耐受的铀浓度高达500 mg/L;铀的去除率随Ca~(2+)浓度的升高而增加;温度在30℃左右和碱性环境有利于方解石与铀的共沉淀。对沉淀产物进行XRD、SEM-EDS表征分析表明,其主要成分为方解石,且包含铀元素;消解分析表明,在方解石形成过程中铀以共沉淀的方式被固定到了沉淀产物中。本研究表明, Sporosarcina pasteurii诱导碳酸盐-铀共沉淀对修复低浓度铀废水有潜在应用前景。
语种：
中文
展开
Enhanced effects and mechanisms of Syngonium podophyllum-Peperomia tetraphylla co-planting on phytoremediation of low concentration uranium-bearing wastewater
作者：
Zhang Yue;Ding Dexin;Li Guangyue;Yi Haitao;Zhai Kaige;...
期刊：
Chemosphere ,2021年279:130810 ISSN：0045-6535
通讯作者：
Wang Yongdong
作者机构：
[Yi Haitao; Li Feng; Wang Yongdong; Zhang Yue; Li Guangyue; Ding Dexin; Hu Nan; Dai Zhongran; Sun Jing; Zhang Hui; Ma Jianhong; Zhai Kaige] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Heng Yang 421001, Hunan, Peoples R China.
通讯机构：
[Wang Yongdong] K;Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Heng Yang, 421001, Hunan, PR China
关键词：
Phytoremediation;Plants co-planting;Uranium;Uranium-bearing wastewater
摘要：
To improve the remediation efficiency of plants on low concentration uranium-bearing wastewater and clarify its strengthening mechanism, Syngonium podophyllum-Peperomia tetraphylla co-planting system was established, the enhanced effects of plants interaction on uranium removal were investigated, the chemical forms, valence states, and subcellular distribution of uranium in plants were confirmed, and the mechanisms of alleviating uranium stress by plants interaction were revealed. In Syngonium podophyllum-Peperomia tetraphylla co-planting system, the total amount of ethanol-extracted uranium and deionized water-extracted uranium with higher toxicity in their roots were reduced by 10.30% and 7.17%, respectively, which reduced the toxicity of uranium to plants. Plants interaction can inhibit the reduction of U(VI) in the root of Peperomia tetraphylla, which is conducive to the transport of uranium from roots to shoots. In addition, uranium in plants mainly existed in the cell wall (54.44%–66.52%) and the soluble fraction (23.85%–32.89%). These results indicated that Syngonium podophyllum and Peperomia tetraphylla co-planting can enhance their effects of uranium removal by alleviating uranium stress with the cell wall immobilization and vacuole compartmentation, improving biomass of plants, increasing bioaccumulation factor and translocation factor of uranium. © 2021 Elsevier Ltd
语种：
英文
展开
黑曲霉两步法与化学氧化联合浸出花岗岩铀矿石
作者：
祖媛媛;李广悦;孙静;李芳艳;王永东
期刊：
核化学与放射化学 ,2021年43(2):142-147 ISSN：0253-9950
作者机构：
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;南华大学 极贫铀资源绿色开发技术湖南省重点实验室,湖南 衡阳 421001;[祖媛媛; 李广悦; 孙静; 李芳艳; 王永东] Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China<&wdkj&>Hunan Province Key Laboratory of Green Development Technology for Extremely Low Grade Uranium Resources, Hengyang, 421001, China
关键词：
花岗岩型铀矿;黑曲霉;两步法;氧化剂;联合浸出
摘要：
为了高效浸出花岗岩型铀矿石中的铀,采用黑曲霉两步法和化学氧化联合浸出,研究预培养时间、浸出时间和不同氧化剂及其用量对浸铀效果的影响。结果表明:黑曲霉两步法浸出时,采用预培养36 h的黑曲霉浸铀,浸出时间为72 h时,铀浸出率最高,为59.34%,随着预培养时间和浸出时间的延长,铀浸出率显著下降。加入MnO_(2)、NaClO_(3)和H_(2)O_(2)三种氧化剂对铀浸出率均有不同程度的提高,其中加入2.5%(与矿石质量比)的MnO_(2)时,浸铀效果最佳,铀浸出率最高可达74.09%,与未加氧化剂相比,铀浸出率提高了14.8%。
语种：
中文
展开
Transport of uranium(VI) in red soil in South China: influence of initial pH and carbonate concentration.
作者：
Fu, Haiying;Ding, Dexin* ;Sui, Yang;Zhang, Hui;Hu, Nan;...
期刊：
Environmental Science and Pollution Research ,2019年26(36):37125-37136 ISSN：0944-1344
通讯作者：
Ding, Dexin
作者机构：
[Ding, Dexin; Zhang, Hui; Ye, Yongjun; Dai, Zhongran; Li, Guangyue; Li, Feng; Hu, Nan; Wang, Yongdong; Fu, Haiying] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;[Ding, Dexin; Zhang, Hui; Ye, Yongjun; Dai, Zhongran; Li, Guangyue; Li, Feng; Hu, Nan; Wang, Yongdong; Fu, Haiying] Hunan Prov Key Lab Green Dev Technol Extremely Lo, Hengyang 421001, Peoples R China.;[Sui, Yang] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Ding, Dexin] U;[Ding, Dexin] H;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;Hunan Prov Key Lab Green Dev Technol Extremely Lo, Hengyang 421001, Peoples R China.
关键词：
Column experiment;Competitive adsorption;Hydrus-1D;Overshoot;Uranium migration
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.
语种：
英文
展开
Linear beta-Cyclodextrin Polymer Functionalized Multiwalled Carbon Nanotubes as Nanoadsorbent for Highly Effective Removal of U(VI) from Aqueous Solution Based on Inner-Sphere Surface Complexation
作者：
Xue, Jin-Hua;Zhang, Hui;Ding, D. X.* ;Hu, Nan;Wang, Yong-Dong;...
期刊：
Industrial & Engineering Chemistry Research ,2019年58(10):4074-4083 ISSN：0888-5885
通讯作者：
Ding, D. X.;Wang, Yong-Sheng
作者机构：
[Zhang, Hui; Hu, Nan; Ding, D. X.; Xue, Jin-Hua; Wang, Yong-Dong] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Hunan, Peoples R China.;[Xue, Jin-Hua; Wang, Yong-Sheng] Univ South China, Coll Publ Hlth, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Ding, D. X.; Wang, Yong-Sheng] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Hunan, Peoples R China.;Univ South China, Coll Publ Hlth, Hengyang 421001, Hunan, Peoples R China.
摘要：
Linear β-cyclodextrin polymer functionalized multiwalled carbon nanotubes (MWCNTs-CDP) were synthesized and employed as a novel nanoadsorbent to remove uranyl ions in wastewater solutions. The characterization of MWCNTs-CDP, with Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET), suggested that the CDP was successfully modified on the MWCNTs surfaces. The removal efficiency of uranyl ions in aqueous solution by MWCNTs-CDP was investigated via varying various experimental conditions. We found that the removal of uranyl ions correlated with both pH and temperature, and the optimum pH and temperature were 6.0 and 323.15 K, respectively. The adsorption of uranyl ions was very fleet at the initial 1 h and then reached the adsorption equilibrium after 3 h. The data from the adsorption dynamics experiment could be commendably fitted by the pseudo-second-order model (R2 > 0.982), suggesting that chemisorption might be the rate-controlling mechanism. The Langmuir model (R2 > 0.995) manifested that the maximum adsorption capacity of uranyl ions on MWCNTs-CDP was boosted from 66.16 to 89.54 mg g-1 upon the change of temperature from 293.15 to 323.15 K. This result was better than that of some reported adsorbents. The thermodynamics analysis proved that the adsorption of uranyl ions on MWCNTs-CDP was a spontaneous process and an endothermic one. The adsorption mechanism of uranyl ions on MWCNTs-CDP was verified to be dominated by inner-sphere surface complexation. Our results indicated that MWCNTs-CDP can be utilized as a novel nanoadsorbent for highly effective removal of uranyl ions in actual uranyl-bearing effluents. © 2019 American Chemical Society.
语种：
英文
展开
Enhanced phytoremediation of uranium contaminated soil by artificially constructed plant community plots
作者：
Sha, Yin-hua;Hu, Nan;Wang, Yong-dong;Chen, Si-yu;Zou, Chao;...
期刊：
Journal of Environmental Radioactivity ,2019年208-209:106036 ISSN：0265-931X
通讯作者：
Ding, De-xin
作者机构：
[Chen, Si-yu; Dai, Zhong-ran; Zhang, Hui; Hu, Nan; Sha, Yin-hua; Ding, De-xin] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Henyang 421001, Peoples R China.;[Zou, Chao; Wang, Yong-dong] Univ South China, Hunan Prov Key Lab Green Dev Technol Exetremely L, Henyang 421001, Peoples R China.;[Ding, De-xin] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, 28 West Changsheng Rd, Hengyang 421001, Hunan, Peoples R China.
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：
Bacteria;Bamboo;Bioaccumulation;Biochemistry;Bioremediation;Contamination;Efficiency;Enzyme activity;Oxalic acid;Soil moisture;Uranium;Contaminated soils;Greenhouse experiments;Microbial community structures;Phytoremediation;Plant communities;Plant growth promoting rhizobacteria;Remediation efficiency;Uptake and accumulations;Soil pollution;carboxylic acid;uranium;uranium;bacterium;bioaccumulation;biomass;bioremediation;community structure;microbial community;phytoremediation;plant community;rhizosphere;soil microorganism;soil pollution;soil remediation;uranium;Article;Bamboo willow;bioaccumulation;biomass;Burkholderia;chelation;community structure;controlled study;enzyme activity;Leptolyngbya;Macleaya cordata;microbial community;nonhuman;Paspalum;Paspalum scrobisculatum;phytoremediation;plant community;rhizosphere;soil pollution;willow;bioremediation;metabolism;soil pollutant;Bacteria (microorganisms);Burkholderia;Leptolyngbya;Macleaya cordata;Paspalum scrobiculatum;Rhizobiales;Salix;Salix sp.;Biodegradation, Environmental;Soil Pollutants, Radioactive;Uranium
摘要：
In order to develop an artificially constructed plant community plot for the enhanced phytoremediation of uranium contaminated soils, three uranium accumulators including Bamboo-willow (Salix sp.), Paspalum scrobiculatum linn and Macleaya cordata were used to construct four artificial plant community plots, and greenhouse experiments were conducted to investigate the bioaccumulation of uranium by the plants and the organic acid content, enzyme activity, and the change of microbial community structure in their rhizosphere soils. The transfer factor (TF) and the total bioaccumulation amount (TBA) of uranium were used to describe remediation efficiencies in this paper. It was found that their remediation efficiencies were in the order Bamboo-willow (Salix sp.)-Paspalum scrobiculatum linn-Macleaya cordata > Bamboo-willow (Salix sp.)-Macleaya cordata > Paspalum scrobiculatum linn-Macleaya cordata > Bamboo-willow (Salix sp.)-Paspalum scrobiculatum linn. The bioaccumulation amount of uranium by each plant in the Bamboo-willow (Salix sp.)-Paspalum scrobiculatum linn-Macleaya cordata community plot was significantly (P < 0.05) higher than that by its single population, the bioaccumulation amounts of uranium by Bamboo-willow (Salix sp.), Paspalum scrobiculatum linn and Macleaya cordata were 0.29, 0.32 and 2.19 mg/plant, respectively, and they were increased by 31.82%, 77.78% and 146.07%, respectively, and the transfer efficiencies by the plants were increased by 150%, 110% and 52.17%, respectively. The interaction between the plants' roots and the microorganisms in the rhizosphere soil of the Bamboo-willow (Salix sp.)-Paspalum scrobiculatum linn-Macleaya cordata community plot resulted in the high content of organic acids such as oxalic acid in the rhizosphere soil of the plant community plot, which was significantly (P < 0.05) higher than that of its single population. The chelation of the organic acids with uranium led to an increase in the proportion of exchangeable uranium in soil solution. In addition, Burkholderia, which is an iron-producing carrier bacterium and can increase the uptake and accumulation of uranium by plants, and Leptolyngbya, which is a plant growth promoting rhizobacteria and can increase the biomass of plants, emerged in the rhizosphere soil of the plant community plot. These may be the mechanisms by which the phytoremediation of the uranium contaminated soils was enhanced by the plant community plot. © 2019 Elsevier Ltd
语种：
英文
展开
Aspergillus niger changes the chemical form of uranium to decrease its biotoxicity, restricts its movement in plant and increase the growth of Syngonium podophyllum
作者：
Zou Chao;Sha Yin-hua;Ding De-xin;Li Guang-yue;Cui Yue-ting;...
期刊：
Chemosphere ,2019年224(Jun.):316-323 ISSN：0045-6535
通讯作者：
Wang Yong-dong
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.
关键词：
Aspergillus niger;Combined remediation system;Phytoremediation;Syngonium podophyllum;Uranium stress
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.
语种：
英文
展开
Bioremediation of effluent from a uranium mill tailings repository in South China by Azolla–Anabaena
作者：
Huang Xinwei;Wang Yongdong;Hu Nan;Sha Yinhua;Ding Dexin*
期刊：
Journal of Radioanalytical and Nuclear Chemistry ,2018年317(2):739-746 ISSN：0236-5731
通讯作者：
Ding Dexin
作者机构：
[Wang Yongdong; Hu Nan; Ding Dexin; Sha Yinhua; Huang Xinwei] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;[Wang Yongdong; Hu Nan; Ding Dexin; Sha Yinhua; Huang Xinwei] Hunan Prov Key Lab Green Dev Technol Extremely Lo, Hengyang 421001, Peoples R China.
通讯机构：
[Ding Dexin] U;[Ding Dexin] H;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;Hunan Prov Key Lab Green Dev Technol Extremely Lo, Hengyang 421001, Peoples R China.
关键词：
cadmium;copper;iron;lead;manganese;nitrogen;phosphorus;sulfate;uranium;zinc;Anabaena;Article;Azolla;bioaccumulation;biomass;bioremediation;China;concentration (parameters);controlled study;effluent;hydroponics;mine tailings;nonhuman;photosynthesis;symbiont
摘要：
Hydroponic experiments were conducted on the removal of uranium, heavy metals and nutrients from the effluent of a uranium mill tailings repository in South China by Azolla–Anabaena. The plant–microbe symbiont was kept in the effluent for 30days, and it was found that U, Fe, Mn, Cu, Zn, Pb, Cd, total phosphorus (TP), total nitrogen (TN) and SO4 2− reduced by 87.6, 99.1, 98.8, 88.2, 91, 78.3, 77.5, 93.4, 98.7 and 76.7%, respectively. Specifically, the concentration of uranium reduced to 0.039mgL−1, which is below the limits of contaminants by the Department of Environmental Protection of China. The concentration of Fe, Cu, Zn, Pb, TP and TN in the effluent reached the quality standard for drinking water. The results showed that Azolla–Anabaena can be used for the bioremediation of the effluent from the uranium mill tailings repository. © 2018, Akadémiai Kiadó, Budapest, Hungary.
语种：
英文
展开
Adsorption and recovery of U(VI) from actual acid radioactive wastewater with low uranium concentration using thioacetamide modified activated carbon from liquorice residue
作者：
Tan, Yan;Li, Le;Zhang, Hui;Ding, Dexin* ;Dai, Zhongran;...
期刊：
Journal of Radioanalytical and Nuclear Chemistry ,2018年317(2):811-824 ISSN：0236-5731
通讯作者：
Ding, Dexin
作者机构：
[Ding, Dexin; Tan, Yan] Cent S Univ, Sch Resources & Safety Engn, Changsha 410083, Hunan, Peoples R China.;[Ding, Dexin; Tan, Yan; Zhang, Hui; Liu, Jinquan; Li, Le; Dai, Zhongran; Hu, Nan; Xue, Jinhua; Wang, Yongdong] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;[Tan, Yan; Liu, Jinquan; Li, Le; Xue, Jinhua] Univ South China, Sch Publ Hlth, Hengyang 421001, Peoples R China.
通讯机构：
[Ding, Dexin] C;[Ding, Dexin] U;Cent S Univ, Sch Resources & Safety Engn, Changsha 410083, Hunan, Peoples R China.;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.
关键词：
activated carbon;thioacetamide;uranium;Article;chemical analysis;chemical reaction;correlation coefficient;energy dispersive X ray spectroscopy;Fourier transform infrared spectroscopy;Glycyrrhiza glabra;kinetics;polymerization;process optimization;radioactivity;temperature;thermodynamics;X ray photoemission spectroscopy;zeta potential
摘要：
In this paper, cheap liquorice residue was used to prepare activated carbon (AC), thioacetamide (TAA) was used to modify the AC, and the adsorption experiments were conducted in the simulated acid radioactive wastewater with low uranium concentration to study the adsorption behavior and mechanism for uranium by TAA modified AC (TAA–AC). The removal efficiency by TAA–AC was 92.1–98.2% from the 1mgL−1 uranium solution at pH 2–6. The adsorption equilibrium data were well fitted by Dubinin–Radushkevich model, and the maximum adsorption capacity was estimated to be 340mgg−1. TAA–AC showed an enhanced selectivity for uranium in the presence of competitive ions. Furthermore, the adsorption experiments were conducted in the actual acid radioactive wastewater with low uranium concentration from an in situ leach uranium mine. The high adsorption rate (98.3%) and selectivity (Kd = 3.78×104mLg−1) for uranium were observed in the actual acid radioactive wastewater, and the adsorption rate was found to maintain 96.2% over six cycles of adsorption–desorption. © 2018, Akadémiai Kiadó, Budapest, Hungary.
语种：
英文
展开
Synthesis and characterization of a novel core–shell magnetic nanocomposite via surface-initiated RAFT polymerization for highly efficient and selective adsorption of uranium(VI)
作者：
Dai, Zhongran;Zhang, Hui;Sui, Yang;Ding, Dexin* ;Hu, Nan;...
期刊：
Journal of Radioanalytical and Nuclear Chemistry ,2018年316(1):369-382 ISSN：0236-5731
通讯作者：
Ding, Dexin
作者机构：
[Ding, Dexin; Zhang, Hui; Li, Le; Dai, Zhongran; Hu, Nan; Wang, Yongdong] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;[Sui, Yang] Hunan Taohuajiang Nucl Power Co Ltd, Yiyang 413000, Peoples R China.
通讯机构：
[Ding, Dexin] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.
关键词：
2 bromopropionyl bromide;adsorbent;amidoxime;aminopropyltriethoxysilane;chemical compound;ethyl potassium dithiocarbonate;magnetic nanoparticle;nanocomposite;nanoshell;polyacrylonitrile;tetraethoxysilane;ultrasmall superparamagnetic iron oxide;unclassified drug;uranium;adsorption kinetics;analytical parameters;Article;concentration (parameters);contact time;controlled study;covalent bond;desorption;infrared spectroscopy;isotherm;nanoanalysis;pH;polymerization;reversible addition fragmentation chain transfer;scanning electron microscopy;structure analysis;surface property;synthesis;temperature sensitivity;thermodynamics;thermogravimetry;transmission electron microscopy;vibrating sample magnetometer;X ray photoelectron spectroscopy
摘要：
In this work, the nanoparticles possessing a macro-initiator (MNPs@SCSOEt) were firstly obtained by surface-initiated RAFT polymerization. The structure of the nanocomposite was characterized by FT-IR, SEM, TEM, TGA, XPS and VSM. The effects of pH, contact time, initial uranium concentrations, coexisting ions and temperature on the U(VI) adsorption by MNPs@PAO were investigated in detail. The adsorption process was found to be in good agreement with pseudo-second order kinetic model and Langmuir adsorption isotherm model. The maximum adsorption capacity was estimated to be 216.45mg/g by fitting Langmuir model with the equilibrium data. The adsorption process was endothermic and spontaneous. In addition, the adsorption capacity of MNPs@PAO for U(VI) decreased slightly after five successive adsorption/desorption cycles. © 2018, Akadémiai Kiadó, Budapest, Hungary.
语种：
英文
展开
富集的硫酸盐还原菌沉积物生物还原地下水中U(Ⅵ)的实验研究
作者：
李殿鑫;胡南;黄超;丁德馨;李广悦;...
期刊：
化工学报 ,2018年69(8):3619-3625 ISSN：0438-1157
通讯作者：
Ding, Dexin(dingdxzzz@163.com)
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
关键词：
废水;沉积物;还原;修复
摘要：
通过添加富集得到的含有丰富的硫酸盐还原菌的沉积物到沉积物-地下水微模型中,并添加乙醇作为碳源,分别与接种硫酸盐还原菌并添加碳源组和仅添加碳源组相比较,研究富集的硫酸盐还原菌沉积物对地下水中U(Ⅵ)还原的作用。结果表明,添加硫酸盐还原菌沉积物组、接种硫酸盐还原菌组和对照组中的铀浓度分别在第19、22和28 d下降至GB 23727—2009规定的0.05 mg·L~(–1)排放标准以下。各组沉积物中具有还原U(Ⅵ)功能的微生物群落的多样性差异较小。添加硫酸盐还原菌沉积物组、接种硫酸盐还原菌组和对照组的沉积物中具有还原U(Ⅵ)功能的微生物群落的丰度分别为35.3%、32.5%和13.1%。由此可见,富集的硫酸盐还原菌沉积物增加了微模型中具有还原U(Ⅵ)功能的微生物群落的丰度,从而促进了U(Ⅵ)的还原。
语种：
中文
展开
Construction of recombinant bioleaching bacteria Thiobacillus ferrooxidans with fluoride-resistant activity
作者：
Yun-Chang Cao;Hong-Bo Wen;Nan Hu;Yong-Dong Wang;Gaung-Yue Li;...
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：
[Yun-Chang Cao; Nan Hu; Yong-Dong Wang; Gaung-Yue Li; De-Xin Ding] 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;[Hong-Bo Wen] Department of Biochemistry and Molecular Biology, School of Pharmaceutical and Biological Science, University of South China, 28 West Changsheng Rd, Hengyang;[Yun-Chang Cao; Hong-Bo Wen; Nan Hu; Yong-Dong Wang; Gaung-Yue Li; De-Xin Ding] Hunan
通讯机构：
[Ding, D.-X.] K;Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, 28 West Changsheng Rd, China
关键词：
Bioleaching bacteria;Conjugation transfer;Flr-4 gene;Fluoride resistance;Genetic modification;Thiobacillus ferrooxidans
摘要：
Thiobacillus ferrooxidans is an important bioleaching bacterium, widely used in leaching, recovery of low-grade metals and environmental bioremediation. In bio-metallurgy industry, fluoride existing in some hard rock uranium deposits in south China severely affects the bacteria viability and inhibit leaching reproduction. In this study, the flr-4 gene that has strong resistance to fluorine ion in Caenorhabditis elegans, was cloned into pET30a vector and expressed in E. coli BL21. the ability of fluoride resistance in E. coli was increased obviously. To increase the fluorideresistance of bioleaching bacterium T. ferrooxidans strain 1 (T.f1), the flr-4 shuttle recombinant plasmid pJRD215-flr-4 was constructed and transferred into T.f1 by conjugation. pJRD215-flr-4 was stable in T.f1 with more than 70% retention after 50 generations. Recombinant T.f1 was tolerant to fluorine ions and grew well under fluoride (F-) stress especially at F- concentrations ranging from 10 mg/L to 60 mg/L. © 2018 Yun-Chang Cao, Hong-Bo Wen, 1Nan Hu, Yong-Dong Wang, Guang-Yue Li and De-Xin Ding.
语种：
英文
展开
Scavenging of U(VI) from Impregnated Water at Uranium Tailings Repository by Tripolyphosphate Intercalated Layered Double Hydroxides
作者：
Zhang, Hui;Dai, Zhongran;Sui, Yang;Wang, Nieying;Fu, Haiying;...
期刊：
Industrial & Engineering Chemistry Research ,2018年57(50):17318-17327 ISSN：0888-5885
通讯作者：
Ding, Dexin
作者机构：
[Ding, Dexin; Zhang, Hui; Li, Le; Dai, Zhongran; Wang, Nieying; Li, Guangyue; Hu, Nan; Wang, Yongdong; Fu, Haiying] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;[Ding, Dexin; Zhang, Hui; Li, Le; Dai, Zhongran; Wang, Nieying; Li, Guangyue; Hu, Nan; Wang, Yongdong; Fu, Haiying] Hunan Prov Key Lab Green Dev Technol Extremely Lo, Hengyang 421001, Peoples R China.;[Sui, Yang; Fu, Haiying] Univ South China, Sch Nucl & Technol, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Ding, Dexin] U;[Ding, Dexin] H;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;Hunan Prov Key Lab Green Dev Technol Extremely Lo, Hengyang 421001, Peoples R China.
摘要：
The impregnated water at a uranium tailings repository has characteristics that its uranium concentration is low and it contains many other interfering ions. In order to develop an efficient adsorbent for such wastewater, Mg-Al layered double hydroxide (Mg-Al-NO3-LDH) and tripolyphosphate intercalated LDH (TPP-LDH-1 and TPP-LDH-2) were synthesized by an anion exchange method and characterized by using multiple analysis techniques, and their behavior and mechanism for U(VI) removal from aqueous solutions were investigated. It is found that their adsorption capacities for U(VI) follow the order Mg-Al-NO3-LDH < TPP-LDH-1 < TPP-LDH-2. The maximum sorption capacities of Mg-Al-NO3-LDH, TPP-LDH-1, and TPP-LDH-2 for U(VI) at pH 5.0 and 298.15 K derived from the Langmuir model are 201.27, 399.01, and 501.76 mg/g, respectively. In addition, tripolyphosphate intercalated LDH show a higher sorption selectivity toward U(VI) over other metal cations and anions. X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared spectroscopy (FT-IR) characterizations suggest that the higher adsorption capacity and sorption selectivity of TPP-LDH-2 are probably due to the inner-sphere surface complexes resulting from the phosphate groups (P=O, -PO3) with U(VI). The applicability of TPP-LDH-2 for scavenging of U(VI) from the impregnated water at a uranium tailings repository in South China was further evaluated. It is found that TPP-LDH-2 shows excellent removal efficiency for U(VI). The results indicate that tripolyphosphate intercalated LDH is a promising adsorbent for scavenging of U(VI) from the impregnated water at the uranium tailings repository. Copyright © 2018 American Chemical Society.
语种：
英文
展开
Transformation of uranium species in soil during redox oscillations
作者：
Fu, Haiying;Zhang, Hui;Sui, Yang;Hu, Nan;Ding, Dexin* ;...
期刊：
Chemosphere ,2018年208(Oct.):846-853 ISSN：0045-6535
通讯作者：
Ding, Dexin
作者机构：
[Ding, Dexin; Zhang, Hui; Ye, Yongjun; Li, Guangyue; Dai, Zhongran; Hu, Nan; Wang, Yongdong; Fu, Haiying] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;[Ding, Dexin; Ye, Yongjun; Sui, Yang; Fu, Haiying] Univ South China, Sch Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.;[Sui, Yang] Hunan Taohuajiang Nucl Power Co Ltd, Yiyang 413000, Peoples R China.
通讯机构：
[Ding, Dexin] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.
关键词：
Redox cycling;Uranium speciation;Stable U(IV);Chemical extraction;Paddy soil
摘要：
Redox oscillation is commonly found in near-surface environment, where soils are often polluted with many redox active contaminants, including uranium (U). In order to investigate the transformation of U species in near-surface soil under redox oscillations conditions, redox oscillations and reduction experiments were performed, biogeochemical parameters and native microbial community composition were monitored, main elements on the surface of solid-phase were analyzed by XPS, and labile U(IV) species and stable U(IV) species in solid-phase were provisionally defined using an anoxic 1 M sodium bicarbonate extraction. It was found that redox oscillations slightly increased the water-soluble U but significantly increased the stable U(IV) species (P < 0.05) in soil. In reduction experiment, there was upper limit value for percentage of stable U(IV) species, and the labile U(IV) species could not transform to stable U(IV) species in a short period of time under reduction conditions. The redox transition of Fe enriched on the surface of soil and the conversion of microbial community composition played a major role in speciation transformation of U under redox oscillations conditions. In addition, sequential extraction revealed that the increase of stable U(IV) species content reflected the U speciation transition from acetate extract to more recalcitrant hydroxylamine extract. The finding provides a potential method for improving the stability of U when bio-reduction is used to remediate the U-contaminated soils. (C) 2018 Elsevier Ltd. All rights reserved.
语种：
英文
展开
