作者：
Ye, Yongjun;Zong, Yifan;Li, Mengyi;Song, Bangzhi
期刊：
Journal of Radioanalytical and Nuclear Chemistry,2025年334(3):2195-2202 ISSN：0236-5731
通讯作者：
Ye, YJ
作者机构：
[Li, Mengyi; Ye, Yongjun; Song, Bangzhi; Zong, Yifan] Univ South China, Sch Resource Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Ye, Yongjun] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Hengyang 421001, Peoples R China.
通讯机构：
[Ye, YJ ] U;Univ South China, Sch Resource Environm & Safety Engn, Hengyang 421001, Peoples R China.;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Hengyang 421001, Peoples R China.
关键词：
Uranium tailings;The free radon production rate;Temperature;Water-solid mass ratio;Particle size
摘要：
The effect of conventional factors on the free radon production rate above 0 degrees C has been widely studied, but rarely explored under frozen conditions. In order to investigate the effect on the free radon production rate of uranium tailings under frozen and non-frozen conditions, uranium tailings from southern China were selected for screening, and temperature, water-solid mass ratio and particle size were used as influencing factors for research. The stable radon concentration and the free radon production rate of uranium tailings of varying particle sizes at different temperatures (20 degrees C, 0 degrees C, - 10 degrees C, - 20 degrees C) and different water-solid mass ratios (0, 0.14, 0.28) were measured by the homemade radon collection tanks. The experimental results showed that: (1) The free radon production rate decreases with temperature decreases, more significantly under frozen conditions, dropping 3.49-4.16% per 1 degrees C on average. (2) Under non-frozen conditions, the free radon production rate rises with water-solid mass ratio rises, while under frozen conditions, the free radon production rate of uranium tailings first increases and then decreases with the increase of water-solid mass ratio. (3) The larger particle size, the lower the free radon production rate. The free radon production rate of uranium tailings with particle size > 450 mu m is 21.3-81.1% lower than that of uranium tailings with other particle sizes.
期刊：
Journal of Environmental Management,2025年386:125756 ISSN：0301-4797
通讯作者：
Zhang, Tao;Yan, Qingyun
作者机构：
[Yan, Qingyun; Fan, Yijun; Yu, Xiaoli; Liu, Shengwei; Ming, Yuzhen; He, Zhili; Su, Erxin; Wu, Kun; Yu, Huang; Liu, Huanping; Liu, Fei; Huang, Zhenyu; Yang, Yufeng; Wang, Cheng; Niu, Mingyang] School of Environmental Science and Engineering, Marine Synthetic Ecology Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Observation and Research Station for Marine Ranching in Lingdingyang Bay, China;[Fan, Yijun; Yu, Xiaoli; Liu, Shengwei; Ming, Yuzhen; He, Zhili; Su, Erxin; Wu, Kun; Yu, Huang; Liu, Huanping; Liu, Fei; Huang, Zhenyu; Yang, Yufeng; Wang, Cheng; Niu, Mingyang] ASEAN Belt and Road Joint Laboratory on Mariculture Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou, Guangdong 510006, PR China;[Ming, Yuzhen] Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, PR China;[Yu, Huang] Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, Hunan 421001, PR China;[Zhang, Tao] School of Agriculture and Biotechnology, Sun Yat-sen University, Shenzhen, Guangdong 518107, PR China. Electronic address: zhangt47@mail.sysu.edu.cn
通讯机构：
[Yan, Qingyun] A;[Zhang, Tao] S;School of Agriculture and Biotechnology, Sun Yat-sen University, Shenzhen, Guangdong 518107, PR China. Electronic address:;ASEAN Belt and Road Joint Laboratory on Mariculture Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou, Guangdong 510006, PR China. Electronic address: yanqingyun@sml-zhuhai.cn
摘要：
Mariculture has expanded significantly in recent decades due to rising seafood demand and its contribution to ocean carbon sequestration. While the mechanisms of carbon sequestration in mariculture are well-established, the roles of microorganisms in sedimentary carbon sequestration have rarely been explored. How microorganisms mediate organic carbon metabolism and their effects on coastal carbon pools remain unclear. Here we tested the carbon fraction and contents, as well as extracellular hydrolase activities in macroalgae culture area, fish or abalone culture area, and control area without mariculture. We profiled microbial community composition and carbon metabolism characteristics in sediments through 16S rRNA gene amplicon sequencing and metagenomics. Our findings revealed that macroalgae culture areas exhibited a significantly greater potential for carbon sequestration than the control area, the concentration of TOC in seawater and the contents of SOC, DOC, and ROC in sediments were significantly ( p < 0.05) increased by 18.93 %, 6.98 %, 33.98 %, and 18.30 % respectively. These results can be attributed to decreased activities of extracellular hydrolase and a lower abundance of carbon-degrading genes. Moreover, metabolic profiling identified taxa from families such as Alteromonadaceae , Pseudomonadaceae , Rhodobacteraceae , Enterobacteriaceae , and Flavobacteriaceae , which are highly metabolically flexible in utilizing a wide range of organic and inorganic energy sources, playing crucial roles in carbon formation. Their respiratory metabolism, such as sulfate reduction, thiosulfate oxidation, and denitrification as well as secondary metabolism products could also affect the formation and persistence of sedimentary carbon pools. Specifically, increased total nitrogen (TN) and nitrate-nitrogen (NO 3 − ) could potentially enhance microbial degradation of organic carbon, decreasing carbon stock within coastal sediments. This study enhanced our understanding of microbial regulation of the organic carbon pool in the mariculture ecosystem.
Mariculture has expanded significantly in recent decades due to rising seafood demand and its contribution to ocean carbon sequestration. While the mechanisms of carbon sequestration in mariculture are well-established, the roles of microorganisms in sedimentary carbon sequestration have rarely been explored. How microorganisms mediate organic carbon metabolism and their effects on coastal carbon pools remain unclear. Here we tested the carbon fraction and contents, as well as extracellular hydrolase activities in macroalgae culture area, fish or abalone culture area, and control area without mariculture. We profiled microbial community composition and carbon metabolism characteristics in sediments through 16S rRNA gene amplicon sequencing and metagenomics. Our findings revealed that macroalgae culture areas exhibited a significantly greater potential for carbon sequestration than the control area, the concentration of TOC in seawater and the contents of SOC, DOC, and ROC in sediments were significantly ( p < 0.05) increased by 18.93 %, 6.98 %, 33.98 %, and 18.30 % respectively. These results can be attributed to decreased activities of extracellular hydrolase and a lower abundance of carbon-degrading genes. Moreover, metabolic profiling identified taxa from families such as Alteromonadaceae , Pseudomonadaceae , Rhodobacteraceae , Enterobacteriaceae , and Flavobacteriaceae , which are highly metabolically flexible in utilizing a wide range of organic and inorganic energy sources, playing crucial roles in carbon formation. Their respiratory metabolism, such as sulfate reduction, thiosulfate oxidation, and denitrification as well as secondary metabolism products could also affect the formation and persistence of sedimentary carbon pools. Specifically, increased total nitrogen (TN) and nitrate-nitrogen (NO 3 − ) could potentially enhance microbial degradation of organic carbon, decreasing carbon stock within coastal sediments. This study enhanced our understanding of microbial regulation of the organic carbon pool in the mariculture ecosystem.
通讯机构：
[Dai, ZR ] U;[Han, S ] H;Hebei Univ Engn, Coll Mat Sci & Engn, Handan Key Lab Novel Nanobiomat, Handan 056000, Peoples R China.;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Hengyang 421001, Peoples R China.
摘要：
Photocatalytic removal of uranium is an efficient method for uranium removal. In this paper, a novel g-C 3 N 4 @C-PAN nanofiber membrane has been prepared by electrospinning and thermal polymerization from carbonized dicyandiamide and polyacrylonitrile fiber film, and it has been used for photocatalytic removal of U( VI ) under LED illumination. The experimental results show that the removal rate of U( VI ) by g-C 3 N 4 @C-PAN was nearly 100% in a wide concentration range of U( VI ) with great anti-interference performance. After 5 cycles, the removal rate of g-C 3 N 4 @C-PAN for uranium remains above 90%, showing excellent reusable performance. The mechanism studies show that the e − and ˙O 2 − play an important role in the photocatalytic removal of U( VI ), and they can react with U( VI ) to form (UO 2 )O 2 ·2H 2 O, thus realizing the fixation and removal of U( VI ). This work shows that the nanofiber membrane prepared by electrospinning technology has considerable application prospects for the photocatalytic treatment of uranium-containing wastewater.
作者机构：
[Tan, Wenfa; Ding, DX; Ding, Dexin; Yu, Huang; Hu, Nan] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;[Yan, Qingyun; Zhang, Dandan; Yan, QY; He, Zhili; Yu, Huang; Liu, Huanping; Chen, Pubo] Sun Yat Sen Univ, Marine Synthet Ecol Res Ctr, China ASEAN Belt & Rd Joint Lab Mariculture Techn, Southern Marine Sci & Engn Guangdong Lab Zhuhai,G, Zhuhai 519082, Peoples R China.;[Liu, Shengwei] Univ Warwick, Sch Life Sci, Coventry CV4 7AL, W Midlands, England.;[Hu, Ruiwen] Lawrence Berkeley Natl Lab, Environm Genom & Syst Biol Div, Berkeley, CA 94720 USA.;[Zhou, Qiang] Jishou Univ, Coll Biol & Environm Sci, Jishou 416000, Xiangxi Tujia &, Peoples R China.
通讯机构：
[Yan, QY ] S;[Ding, DX ] U;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Peoples R China.;Sun Yat Sen Univ, Marine Synthet Ecol Res Ctr, China ASEAN Belt & Rd Joint Lab Mariculture Techn, Southern Marine Sci & Engn Guangdong Lab Zhuhai,G, Zhuhai 519082, Peoples R China.
关键词：
arsenic methylation;dissimilatory nitrate reduction to ammonium;microorganism enrichment;nitrogen fixation;phytoremediation
摘要：
Plants can recruit microorganisms to enhance soil arsenic (As) removal and nitrogen (N) turnover, but how microbial As methylation in the rhizosphere is affected by N biotransformation is not well understood. Here, we used acetylene reduction assay, arsM gene amplicon, and metagenome sequencing to evaluate the influence of N biotransformation on As methylation in the rhizosphere of Vetiveria zizanioides, a potential As hyperaccumulator. V. zizanioides was grown in mining soils (MS) and artificial As-contaminated soils (AS) over two generations in a controlled pot experiment. Results showed that the content of dimethylarsinic acid in the rhizosphere was significantly positively correlated with the rate of N fixation and the activity of nitrite reductase. The As-methylating species (e.g., Flavisolibacter and Paraflavitalea) were significantly enriched in the root-associated compartments in the second generation of MS and AS. Notably, higher abundance of genes involved in N fixation (nifD, nifK) and dissimilatory nitrate reduction to ammonium (narG/H, nirB/D/K/S) was detected in the second generation of MS than in the first generation. The metabolic pathway analysis further demonstrated that N fixing-stimulative and DNRA-stimulative As-methylating species could provide ammonium to enhance the synthesis of S-adenosyl-l-methionine, serving as methyl donors for soil As methylation. This study highlights two important N conversion-stimulative As-methylating pathways and has important implications for enhancing phytoremediation in As-contaminated soils.
期刊：
Nuclear Engineering and Technology,2025年57(10):103691 ISSN：1738-5733
通讯作者：
Yongjun Ye
作者机构：
[Xuanli Yao; Daijia Chen; Ning Zhou] School of Resources Environment and Safety Engineering, University of South China, Hengyang, 421001, China;Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China;National & Local Joint Engineering Research Center for Airborne Pollutants Control and Radioactivity Protection in Buildings, University of South China, Hengyang, 421001, China;[Yongjun Ye] School of Resources Environment and Safety Engineering, University of South China, Hengyang, 421001, China<&wdkj&>Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China<&wdkj&>National & Local Joint Engineering Research Center for Airborne Pollutants Control and Radioactivity Protection in Buildings, University of South China, Hengyang, 421001, China
通讯机构：
[Yongjun Ye] S;School of Resources Environment and Safety Engineering, University of South China, Hengyang, 421001, China<&wdkj&>Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, China<&wdkj&>National & Local Joint Engineering Research Center for Airborne Pollutants Control and Radioactivity Protection in Buildings, University of South China, Hengyang, 421001, China
摘要：
In order to study the laws of radon reduction ventilation in a stope with trackless Z-shaped filling method, the actual geometric structure, ventilation parameters, and radon exhalation rate of the exposed surface of this type of stope are determined. The air flow rate distribution, average radon concentration and the volume proportion exceeding the stipulated limit in stopes of different heights were studied by CFD method for the direct ventilation structure and the improved structure with adjustable air curtain. The results show that: 1) For the existing ventilation structure, with the increase of the height of the stope, the air flow rate into the workspace of the stope gradually decreases, and is lower than the required value for radon reduction in the stope, resulting in the average radon concentration in the stope greatly exceeding the stipulated limit. 2) For the improved structure with an adjustable air curtain at the upper mouth of the Z-shaped ramp, the air flow rate can be effectively allocated to the workspace of the stope, and the average radon concentration and the volume proportion exceeding the stipulated limit can be reduced. 3) Based on the numerical simulation results, the relation between the air flow rate of the workspace and the total air flow rate, the height of the stope, and the area ratio of adjustable air curtain to ramp is established, which provides a reference for optimizing the air flow rate distribution of radon reduction ventilation by adjusting the area ratio of adjustable air curtain to ramp.
In order to study the laws of radon reduction ventilation in a stope with trackless Z-shaped filling method, the actual geometric structure, ventilation parameters, and radon exhalation rate of the exposed surface of this type of stope are determined. The air flow rate distribution, average radon concentration and the volume proportion exceeding the stipulated limit in stopes of different heights were studied by CFD method for the direct ventilation structure and the improved structure with adjustable air curtain. The results show that: 1) For the existing ventilation structure, with the increase of the height of the stope, the air flow rate into the workspace of the stope gradually decreases, and is lower than the required value for radon reduction in the stope, resulting in the average radon concentration in the stope greatly exceeding the stipulated limit. 2) For the improved structure with an adjustable air curtain at the upper mouth of the Z-shaped ramp, the air flow rate can be effectively allocated to the workspace of the stope, and the average radon concentration and the volume proportion exceeding the stipulated limit can be reduced. 3) Based on the numerical simulation results, the relation between the air flow rate of the workspace and the total air flow rate, the height of the stope, and the area ratio of adjustable air curtain to ramp is established, which provides a reference for optimizing the air flow rate distribution of radon reduction ventilation by adjusting the area ratio of adjustable air curtain to ramp.
期刊：
Separation and Purification Technology,2025年354:129241 ISSN：1383-5866
通讯作者：
Zhongran Dai
作者机构：
[Dai, Zhongran; Liang, Beichao; Chen, Lijie] Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China;[Zhang, Weilin] College of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, Hunan, China;[Gao, Yuan] School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China;[Li, Le] Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China<&wdkj&>College of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, Hunan, China
通讯机构：
[Zhongran Dai] K;Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China
摘要：
Photocatalysis holds promise for extracting uranium from aqueous solution. Nevertheless, conventional approaches generally rely on sacrificial agents and anaerobic conditions to maintain photocatalytic efficiency, which increases costs and causes secondary pollution. Herein, we introduce the design and synthesis of an S-scheme ZnIn2S4/g-C3N4 (ZISCN) heterojunction photocatalyst for the efficient removal of uranium via in-situ generating ZnIn2S4 on g-C3N4. Photoelectric characterization and theoretical calculation indicate that ZISCN boosts the absorption of visible light and promotes the effective separation and migration of charge carriers by forming an internal electric field (IEF) at the S-scheme heterojunction interface. This configuration integrates the strong reducing electrons of g-C3N4 and the potent oxidation holes of ZnIn2S4. Consequently, the as-synthesized ZISCN can efficiently remove uranium under an air atmosphere without the need for sacrificial agents and anaerobic conditions. The achieved U(VI) removal rate of 94.8 % surpasses that of ZnIn2S4 and g-C3N4 individually. Moreover, the photocatalytic extraction of U(VI) by ZISCN photocatalyst demonstrated excellent stability and anti-interference performance. After five cycles, the U(VI) removal rate remained above 85 %. Mechanism studies reveal that when electrons are generated by light in the ZISCN systems, they can reduce O2, leading to the formation of reactive species ·O2/H2O2. These species subsequently interact with U(VI), resulting in the precipitation of (UO2)O2·2H2O on the surface of ZISCN. This research provides valuable insights for the design of heterojunction photocatalysts for efficient, sacrificial agent-free uranium removal in ambient air environments.
摘要：
Uranium is the core material for the development of the nuclear industry, but its irreversible radiation damage poses a significant threat to human health. In this context, an innovative dual-mode colorimetric and electrochemical sensor was developed for the detection of uranyl ions (UO(2)(2+)), utilizing a covalent organic framework@gold nanoclusters (AuNCs@COF) composite. The synthesis of AuNCs@COF was simple, and the incorporation of AuNCs imparted the composite with exceptional peroxidase-like catalytic activity and enhanced electrochemical properties. By regulating the adsorption and desorption of aptamers on the AuNCs@COF surface, both peroxidase-like activity and conductivity were modulated, enabling the detection of UO(2)(2+) utilizing colorimetric and electrochemical dual signals. Under optimal conditions, the sensor revealed a broad linear detection range and a low detection limit, with ranges of 1.36 × 10(-10)-1.36 × 10(-5)mol/L for colorimetric detection and 5.0 × 10(-10)-2.5 × 10(-5)mol/L for electrochemical detection, achieving detection limitsfor these two methodsof 107 pmol/L and 347 pmol/L, respectively. Unlike other single-mode sensorsfor UO(2)(2+) detection, this dual-mode sensor demonstrated superior sensitivity, specificity, and repeatability. Furthermore, the results of spiked recovery experiments in real water samples highlight the promising potential of this dual-mode sensor for environmental water monitoring applications.
摘要：
During the in-situ leaching process of sandstone uranium ore deposits, the dynamic evolution of reactive transport parameters, including permeability, tortuosity, and specific surface area (SSA), plays a crucial role in solution flow and solute transport. Characterizing the evolution of these parameters is essential for understanding the leaching process. However, the heterogeneous pore structure of sandstone renders porosity alone insufficient to capture changes in these parameters. This study combines porosity and lacunarity to comprehensively characterize these parameters. For this purpose, leaching experiments were conducted on sandstone uranium ore samples, and CT imaging was performed at different leaching time points. The evolution of reactive transport parameters was analyzed by studying cubic subsamples from the images. The results indicate that both porosity and lacunarity are significant factors influencing the reactive transport parameters. However, neither parameter alone adequately characterizes their evolution. In contrast, combining them accurately characterizes the evolution of reactive transport parameters. Porosity reflects pore quantity, while lacunarity represents pore heterogeneity. Combining these measures facilitates a comprehensive understanding of the evolution of reactive transport parameters and the influence of pore microstructure on macroscopic reactive transport parameters. This research provides valuable insights for optimizing the leaching process in sandstone uranium ore deposits.
During the in-situ leaching process of sandstone uranium ore deposits, the dynamic evolution of reactive transport parameters, including permeability, tortuosity, and specific surface area (SSA), plays a crucial role in solution flow and solute transport. Characterizing the evolution of these parameters is essential for understanding the leaching process. However, the heterogeneous pore structure of sandstone renders porosity alone insufficient to capture changes in these parameters. This study combines porosity and lacunarity to comprehensively characterize these parameters. For this purpose, leaching experiments were conducted on sandstone uranium ore samples, and CT imaging was performed at different leaching time points. The evolution of reactive transport parameters was analyzed by studying cubic subsamples from the images. The results indicate that both porosity and lacunarity are significant factors influencing the reactive transport parameters. However, neither parameter alone adequately characterizes their evolution. In contrast, combining them accurately characterizes the evolution of reactive transport parameters. Porosity reflects pore quantity, while lacunarity represents pore heterogeneity. Combining these measures facilitates a comprehensive understanding of the evolution of reactive transport parameters and the influence of pore microstructure on macroscopic reactive transport parameters. This research provides valuable insights for optimizing the leaching process in sandstone uranium ore deposits.
摘要：
Utilizing oxidants to convert non-leachable tetravalent uranium (U 4+ ) into leachable hexavalent uranium (U 6+ ) is a prerequisite for the effective and economical recovery of uranium from its ore. However, conventional oxidants often face significant challenges related to economic viability, environmental sustainability, and operational practicality. To address these limitations, a novel approach utilizing oxygen nanobubbles (NBs) as an innovative oxidant is proposed to enhance the efficiency of sulfuric acid leaching for uranium extraction. This method demonstrates notable advantages in improving uranium recovery rates, reducing industrial costs, and minimizing environmental impact. Experimental results reveal that a column reactor employing oxygen NBs achieves significantly higher uranium leaching efficiencies compared to traditional oxygen-aerated oxidation systems, with an 8.02 % increase in recovery. The analysis of the enhanced leaching mechanism indicates that the improvement in leaching efficiency is primarily attributed to the ability of oxygen NBs to continuously deliver dissolved oxygen at super-equilibrium concentrations and generate highly reactive hydroxyl radicals, which significantly promote the oxidation of U 4+ , particularly through the indirect oxidation pathway mediated by the Fe 3+ /Fe 2+ electron pair. Further analysis of the leach residues indicates that the improved leaching efficiency is also linked to the anti-precipitation and microarea effects induced by oxygen NBs. These effects not only mitigate leaching inhibition caused by surface precipitation but also induce additional structural damage to the ore, thereby expanding the leaching pathways for uranium. Collectively, these findings underscore the potential of oxygen NB technology as a transformative approach in uranium metallurgy, offering an efficient, economical, and environmentally friendly oxidation strategy that supports the sustainable development of the nuclear industry.
Utilizing oxidants to convert non-leachable tetravalent uranium (U 4+ ) into leachable hexavalent uranium (U 6+ ) is a prerequisite for the effective and economical recovery of uranium from its ore. However, conventional oxidants often face significant challenges related to economic viability, environmental sustainability, and operational practicality. To address these limitations, a novel approach utilizing oxygen nanobubbles (NBs) as an innovative oxidant is proposed to enhance the efficiency of sulfuric acid leaching for uranium extraction. This method demonstrates notable advantages in improving uranium recovery rates, reducing industrial costs, and minimizing environmental impact. Experimental results reveal that a column reactor employing oxygen NBs achieves significantly higher uranium leaching efficiencies compared to traditional oxygen-aerated oxidation systems, with an 8.02 % increase in recovery. The analysis of the enhanced leaching mechanism indicates that the improvement in leaching efficiency is primarily attributed to the ability of oxygen NBs to continuously deliver dissolved oxygen at super-equilibrium concentrations and generate highly reactive hydroxyl radicals, which significantly promote the oxidation of U 4+ , particularly through the indirect oxidation pathway mediated by the Fe 3+ /Fe 2+ electron pair. Further analysis of the leach residues indicates that the improved leaching efficiency is also linked to the anti-precipitation and microarea effects induced by oxygen NBs. These effects not only mitigate leaching inhibition caused by surface precipitation but also induce additional structural damage to the ore, thereby expanding the leaching pathways for uranium. Collectively, these findings underscore the potential of oxygen NB technology as a transformative approach in uranium metallurgy, offering an efficient, economical, and environmentally friendly oxidation strategy that supports the sustainable development of the nuclear industry.
摘要：
Uranium (U) can impact microbially driven soil phosphorus (P) and carbon (C) cycling. However, the response of microbial P and C turnover to U in different soils is not well understood. Through the quantitative assay of P pools and soil organic C (SOC) quantitative assay and sequencing of 16S rRNA gene amplicons and metagenomes, we investigated the effect of U on P and C biotransformation in grassland (GL), paddy soil (PY), forest soil (FT). U (60 mg kg -1 ) impacted the diversity, interaction and stability of soil bacterial communities, leading to a decrease in available P (AP). Under U stress, organophosphate mineralization substantially contributed to the AP in GL and FT, whereas intracellular P metabolism dominated the AP in PY. Also, the reductive citrate cycle (rTCA cycle) promoted the content of SOC in GL, while the rTCA cycle and complex organic C degradation pathways enhanced the SOC in PY and FT, respectively. Notably, functional bacteria carrying organic C degradation genes could decompose SOC to enhance soil AP. Bacteria developed various resistance strategies to cope with U stress. This study reveals soil-dependent response of microbial P and C cycling and its ecological functions under the influence of radioactive contaminants in different soil systems.
Uranium (U) can impact microbially driven soil phosphorus (P) and carbon (C) cycling. However, the response of microbial P and C turnover to U in different soils is not well understood. Through the quantitative assay of P pools and soil organic C (SOC) quantitative assay and sequencing of 16S rRNA gene amplicons and metagenomes, we investigated the effect of U on P and C biotransformation in grassland (GL), paddy soil (PY), forest soil (FT). U (60 mg kg -1 ) impacted the diversity, interaction and stability of soil bacterial communities, leading to a decrease in available P (AP). Under U stress, organophosphate mineralization substantially contributed to the AP in GL and FT, whereas intracellular P metabolism dominated the AP in PY. Also, the reductive citrate cycle (rTCA cycle) promoted the content of SOC in GL, while the rTCA cycle and complex organic C degradation pathways enhanced the SOC in PY and FT, respectively. Notably, functional bacteria carrying organic C degradation genes could decompose SOC to enhance soil AP. Bacteria developed various resistance strategies to cope with U stress. This study reveals soil-dependent response of microbial P and C cycling and its ecological functions under the influence of radioactive contaminants in different soil systems.
摘要：
Herein, a novel composite cathode material of Ni foam supported by amidoxime cellulose microspheres (ACM@Ni) has been prepared. The removal rate of U(VI) can reach 95% within 4 h under the conditions of 298.15 K, pH = 4 and 1.2 V, which was 5 times faster than the physical adsorption. The adsorption data of U(VI) were consistent with the quasi-first-order kinetic and Freundlich isotherm model, revealing the multilayer chemisorption process of uranium on the ACM-5@Ni cathode. In addition, ACM-5@Ni electrode materials also have potential application prospects in the actual treatment of uranium containing wastewater. XRD and XPS studies show that the U(VI) adsorbed by ACM-5@Ni cathode was reduced to U(IV) in the process of uranium removal.
期刊：
Nuclear Engineering and Technology,2025年57(6):103435 ISSN：1738-5733
通讯作者：
Haiying Fu
作者机构：
Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, PR China;[Lian, Meng; Yang, Zhiman; He, Guicheng"] School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, PR China;["Fu, Haiying; Ding, Dexin] Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, PR China<&wdkj&>School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, PR China
通讯机构：
[Haiying Fu] K;Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang, 421001, PR China<&wdkj&>School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, PR China
摘要：
Based upon the lattice Boltzmann method, the current paper developed a visual simulation method for the evolution of porous structure during the acid leaching process. The reliability of the model in simulating fluid flow, solute diffusion, calcite dissolution, and gypsum precipitation was validated using four benchmark tests. The model was then used to investigate the effects of calcite distribution, sulfuric acid concentration, and porous structure on reactive transport processes. Results demonstrated that simulated values closely aligned with theoretical solutions or experimental data, confirming the model's validity. Applications showed that, when calcite was distributed near the injection end, precipitation near the inlet led to a rapid permeability decline. Higher sulfuric acid concentrations caused faster permeability reduction. The porous structure distribution significantly impacted permeability evolution, especially when blockades in main flow paths greatly affected permeability and reactive transport processes. Furthermore, when pore and mineral distributions were homogeneous, permeability evolution with porosity followed a power-law relationship, but this relationship did not hold when distributions were heterogeneous. Due to the difficulty in quantifying mineral and pore heterogeneities, combining porous structure and mineral distribution images with visual simulations created a practical approach for studying dynamic reactive transport in in-situ acid leaching of sandstone uranium deposits.
Based upon the lattice Boltzmann method, the current paper developed a visual simulation method for the evolution of porous structure during the acid leaching process. The reliability of the model in simulating fluid flow, solute diffusion, calcite dissolution, and gypsum precipitation was validated using four benchmark tests. The model was then used to investigate the effects of calcite distribution, sulfuric acid concentration, and porous structure on reactive transport processes. Results demonstrated that simulated values closely aligned with theoretical solutions or experimental data, confirming the model's validity. Applications showed that, when calcite was distributed near the injection end, precipitation near the inlet led to a rapid permeability decline. Higher sulfuric acid concentrations caused faster permeability reduction. The porous structure distribution significantly impacted permeability evolution, especially when blockades in main flow paths greatly affected permeability and reactive transport processes. Furthermore, when pore and mineral distributions were homogeneous, permeability evolution with porosity followed a power-law relationship, but this relationship did not hold when distributions were heterogeneous. Due to the difficulty in quantifying mineral and pore heterogeneities, combining porous structure and mineral distribution images with visual simulations created a practical approach for studying dynamic reactive transport in in-situ acid leaching of sandstone uranium deposits.
摘要：
Developing eco-friendly and highly efficient uranium-enhanced leaching technologies is crucial for ensuring the reliable supply of uranium resources. This study integrates nanobubble (NB) technology into the acid leaching process of granite-type uranium ore by employing oxygen NBs as an effective, clean oxidant to enhance uranium leaching. The feasibility of using oxygen NBs was first validated theoretically, and subsequent batch experiments were conducted to investigate the enhanced leaching kinetics and mechanism. The results demonstrate that oxygen NB-enhanced leaching follows a shrinking core model dominated by product layer diffusion, with an Arrhenius activation energy of 8.37 kJ/mol. Under optimal conditions (15 g/L H 2 SO 4 , 180 rpm, 5 % pulp density, and 30 °C), oxygen NBs increased uranium leaching efficiency by 8.20 % compared to conventional sulfuric acid leaching. Three key mechanisms contribute to this enhancement: (i) efficient oxidation of U(IV) to U(VI) via continuous dissolution of molecular oxygen and generation of hydroxyl radicals; (ii) expansion of leaching pathways through high-energy microarea effects that further disrupt the ore structure; and (iii) reduction of leaching inhibition by preventing sulfate precipitate deposition on mineral surfaces. These findings underscore the potential of oxygen NB-enhanced oxidative leaching for sustainable, cost-effective uranium extraction, warranting pilot-scale studies for industrial application.
Developing eco-friendly and highly efficient uranium-enhanced leaching technologies is crucial for ensuring the reliable supply of uranium resources. This study integrates nanobubble (NB) technology into the acid leaching process of granite-type uranium ore by employing oxygen NBs as an effective, clean oxidant to enhance uranium leaching. The feasibility of using oxygen NBs was first validated theoretically, and subsequent batch experiments were conducted to investigate the enhanced leaching kinetics and mechanism. The results demonstrate that oxygen NB-enhanced leaching follows a shrinking core model dominated by product layer diffusion, with an Arrhenius activation energy of 8.37 kJ/mol. Under optimal conditions (15 g/L H 2 SO 4 , 180 rpm, 5 % pulp density, and 30 °C), oxygen NBs increased uranium leaching efficiency by 8.20 % compared to conventional sulfuric acid leaching. Three key mechanisms contribute to this enhancement: (i) efficient oxidation of U(IV) to U(VI) via continuous dissolution of molecular oxygen and generation of hydroxyl radicals; (ii) expansion of leaching pathways through high-energy microarea effects that further disrupt the ore structure; and (iii) reduction of leaching inhibition by preventing sulfate precipitate deposition on mineral surfaces. These findings underscore the potential of oxygen NB-enhanced oxidative leaching for sustainable, cost-effective uranium extraction, warranting pilot-scale studies for industrial application.
期刊：
Science of The Total Environment,2025年958:177896 ISSN：0048-9697
通讯作者：
Dexin Ding
作者机构：
[Li, Guangyue; Li, Aishu; Yi, Haitao; Wang, Yongdong; Wang, Haonan] Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Heng Yang 421001, Hunan, PR China;[Ding, Dexin] Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Heng Yang 421001, Hunan, PR China. Electronic address: Ddingusc@163.com
通讯机构：
[Dexin Ding] 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：
Acidic groundwater;In site bioremediation;Nitrate;Tumebacillus;Uranium
摘要：
In-situ leaching (ISL) is the predominant technology used in uranium mining currently, although it leads to significant environmental challenges. Nitrates, a key component in leaching agents, not only pose a threat to human health but also impede the bioreduction of U(VI) in uranium-contaminated water. In this study, the nitrate reducing bacterial (NRB) communities adapted to acidic uranium-contaminated groundwater from a site in Northwest China were gained by an enrichment micro-model. The effects of the NRB communities on the groundwater parameters and microbial diversity were evaluated using the groundwater-core column leaching system during the in-situ bioremediation of nitrate. The enrichment experiments revealed that NRB communities adapted to acidic uranium-contaminated groundwater were successfully enriched, of which Tumebacillus was the main functional bacterium. The column leaching experiment results showed that adding NRB communities successfully reduced nitrate levels from 100.91 mg/L to 0.7 mg/L in just 8 days, improved groundwater acidity and redox conditions. Additionally, the metagenomic analysis showed that introducing NRB communities increased biomass and indigenous NRB, but decreased microbial diversity. The KEGG enrichment analysis suggested that butanoate metabolism and valine, leucine and isoleucine degradation were promoted by adding enriched NRB communities. This research lays the groundwork for nitrate removal from contaminated groundwater in areas affected by ISL in uranium mines, setting the stage for future in situ bioremediation of U(VI).
In-situ leaching (ISL) is the predominant technology used in uranium mining currently, although it leads to significant environmental challenges. Nitrates, a key component in leaching agents, not only pose a threat to human health but also impede the bioreduction of U(VI) in uranium-contaminated water. In this study, the nitrate reducing bacterial (NRB) communities adapted to acidic uranium-contaminated groundwater from a site in Northwest China were gained by an enrichment micro-model. The effects of the NRB communities on the groundwater parameters and microbial diversity were evaluated using the groundwater-core column leaching system during the in-situ bioremediation of nitrate. The enrichment experiments revealed that NRB communities adapted to acidic uranium-contaminated groundwater were successfully enriched, of which Tumebacillus was the main functional bacterium. The column leaching experiment results showed that adding NRB communities successfully reduced nitrate levels from 100.91 mg/L to 0.7 mg/L in just 8 days, improved groundwater acidity and redox conditions. Additionally, the metagenomic analysis showed that introducing NRB communities increased biomass and indigenous NRB, but decreased microbial diversity. The KEGG enrichment analysis suggested that butanoate metabolism and valine, leucine and isoleucine degradation were promoted by adding enriched NRB communities. This research lays the groundwork for nitrate removal from contaminated groundwater in areas affected by ISL in uranium mines, setting the stage for future in situ bioremediation of U(VI).
摘要：
The radon released from the exposed uranium tailings pond beach has an undeniable impact on the surrounding environment. In order to reveal the rules of radon exhalation on the uranium tailings pond beach under the action of wind field, a radon migration model was established under the coupling conditions of atmosphere and uranium tailings pond, and the radon exhalation rate of the beach was determined using CFD (Computational fluid dynamics) under different wind speeds (
$${v}_{{G}_{0}}$$
= 0 m/s, 0.4 m/s, 2 m/s, and 4 m/s) and permeabilities (K = 1.0 × 10−11 m2, 1.0 × 10−9 m2, and 1.0 × 10−8 m2). The results show that: (1) the radon exhalation rate on the beach is unevenly distributed under the effect of external wind field, its average value increases with the increase of wind speed and permeability, (2) the smaller the permeability, the less significant the effect of wind speed on the radon exhalation rate of the beach. This study provides a reference for estimating and evaluating the radon exhalation rate and total radon release amount of the beaches under external wind fields, as well as for suppressing radon release.
期刊：
Nuclear Engineering and Technology,2025年57(9):103638 ISSN：1738-5733
通讯作者：
Ye, YJ
作者机构：
[Ye, Yongjun; Zhou, Ning; Yu, Ting] Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Ye, Yongjun] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Hengyang 421001, Peoples R China.
通讯机构：
[Ye, YJ ] U;Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Peoples R China.
关键词：
Under non-isothermal conditions;Radon exhalation rate;CFD
摘要：
Seasonal climate change profoundly affects radon release from uranium tailings beaches. This study evaluates radon migration in uranium tailings reservoirs by developing a non-isothermal radon migration model that incorporates freeze-thaw cycles. Using Computational Fluid Dynamics (CFD) numerical simulations combined with temperature and moisture control equations, the research analyzes the effects of atmospheric temperature variations on radon migration. The study examines the migration and exhalation patterns during typical heating and cooling stages. Findings reveal that both temperature and effective water saturation significantly influence radon migration parameters. Specifically, radon exhalation rates increase with tailings temperature, while freezing conditions notably restrict radon migration and release. This research provides a theoretical foundation for dynamically estimating radon exhalation rates and assessing radon pollution on uranium tailings surfaces in response to seasonal temperature fluctuations.
Seasonal climate change profoundly affects radon release from uranium tailings beaches. This study evaluates radon migration in uranium tailings reservoirs by developing a non-isothermal radon migration model that incorporates freeze-thaw cycles. Using Computational Fluid Dynamics (CFD) numerical simulations combined with temperature and moisture control equations, the research analyzes the effects of atmospheric temperature variations on radon migration. The study examines the migration and exhalation patterns during typical heating and cooling stages. Findings reveal that both temperature and effective water saturation significantly influence radon migration parameters. Specifically, radon exhalation rates increase with tailings temperature, while freezing conditions notably restrict radon migration and release. This research provides a theoretical foundation for dynamically estimating radon exhalation rates and assessing radon pollution on uranium tailings surfaces in response to seasonal temperature fluctuations.
摘要：
Residual sludge (RS) from a wastewater treatment plant was used to prepare sludge-based biochar (RS-BC) by pyrolysis to treat U(VI)-containing wastewater. The findings revealed that RS-BC had exceptional adsorption performance, with a theoretical maximum adsorption capacity for U(VI) of 455.69 mg g(-1). The pseudo-second-order and Langmuir isotherm adsorption models effectively fit the adsorption process, and the thermodynamic parameters confirmed that the adsorption process was endothermic and spontaneous. The adsorption efficiency of U(VI) onto RS-BC exhibited remarkable stability and maintained a notable 90% retention even after five cycles of adsorption and desorption. Spectroscopic analyses revealed that ion exchange and complexation were the main adsorption mechanisms.
摘要：
To investigate the relationship between the radon diffusion coefficient and free-radon production rate with ambient temperature and water saturation of uranium tailings under frozen and non-frozen conditions, a method was proposed to simultaneously determine the free-radon production rate as well as the diffusion coefficient in porous emanation media based on the pure diffusion migration theory of radon. The diffusion coefficient (alpha), the free-radon production rate (D), and gas permeability (K) of radon at different temperatures (20 degrees C, 0 degrees C, - 10 degrees C and - 20 degrees C) and water content saturation (m = 0 and m = 0.52) were determined by a self-made experiment device. The results showed that: (1) the free-radon production rate and the diffusion coefficient of uranium tailings increased with the increase of temperature in the range of 0.77-4.80 Bq<middle dot>m-3<middle dot>s-1 and 1.56 x 10-6-3.27 x 10-6 m2<middle dot>s-1, respectively, when the temperature was in the range of - 20 to 20 degrees C. (2) With the increase of temperature, the free-radon production rate of dry uranium tailings and uranium tailings with a water saturation of 0.52 increased linearly, and the diffusion coefficient increased nonlinearly; (3) the permeability of uranium tailings with a water saturation of 0.52 at the same temperature was less than that of dry uranium tailing, and the former increased with increasing temperature, while the latter was the opposite. The methods and data obtained in this study can provide references for further research in this field, and the relevant results can be used to evaluate the potential environmental effects of radon migration parameters in uranium tailings ponds under different seasonal temperatures and water saturation conditions.
摘要：
Mercury (Hg) pollution poses a critical threat to human health and the environment, necessitating urgent control measures. This study introduces a novel modification method for the common zero-valent iron-carbon (ZVI-AC) galvanic cells using a two-step process, nonthermal (NTP) irradiation followed by targeted functionalization, aiming to enhance Hg adsorption potential by adjusting the physicochemical properties of the cells. The NTP irradiated functionalized adsorbent demonstrated superior Hg adsorption performance across various concentrations and pH variations. Multichannel adsorption mechanisms were confirmed by fitting a total of 22 different adsorption isotherm models, indicating the coexistence of monolayer and multilayer adsorption processes. The NTP irradiation modifies the ZVI and AC, inducing nitrogen and oxygen doping on carbon-based surfaces and oxidizing ZVI to Fe(II)-Fe(III) species. The deepened oxidation of Fe in NTP-Fe-C, coupled with Hg 2+ reduction to elemental Hg by raw Fe, contributed to Hg removal. NTP irradiation facilitated electron transfer between Fe and Hg, promoting oxidation of Fe and reduction of Hg 2+ cations. The emergence of diverse Hg species further supported the multichannel adsorption/removal mechanism achieved by NTP-irradiated cells. This method offers a promising solution to Hg pollution and expands the application of the traditional iron-carbon galvanic cells in treating hazardous heavy metal wastes.
Mercury (Hg) pollution poses a critical threat to human health and the environment, necessitating urgent control measures. This study introduces a novel modification method for the common zero-valent iron-carbon (ZVI-AC) galvanic cells using a two-step process, nonthermal (NTP) irradiation followed by targeted functionalization, aiming to enhance Hg adsorption potential by adjusting the physicochemical properties of the cells. The NTP irradiated functionalized adsorbent demonstrated superior Hg adsorption performance across various concentrations and pH variations. Multichannel adsorption mechanisms were confirmed by fitting a total of 22 different adsorption isotherm models, indicating the coexistence of monolayer and multilayer adsorption processes. The NTP irradiation modifies the ZVI and AC, inducing nitrogen and oxygen doping on carbon-based surfaces and oxidizing ZVI to Fe(II)-Fe(III) species. The deepened oxidation of Fe in NTP-Fe-C, coupled with Hg 2+ reduction to elemental Hg by raw Fe, contributed to Hg removal. NTP irradiation facilitated electron transfer between Fe and Hg, promoting oxidation of Fe and reduction of Hg 2+ cations. The emergence of diverse Hg species further supported the multichannel adsorption/removal mechanism achieved by NTP-irradiated cells. This method offers a promising solution to Hg pollution and expands the application of the traditional iron-carbon galvanic cells in treating hazardous heavy metal wastes.
期刊：
Journal of Hazardous Materials,2025年490:137863 ISSN：0304-3894
通讯作者：
Ye, YJ
作者机构：
[Ye, Yongjun; Wang, Haofeng] Univ South China, Natl Joint Engn Res Ctr Airborne Pollutants Contro, Hengyang 421001, Hunan, Peoples R China.;[Ye, Yongjun] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Hengyang 421001, Peoples R China.;[Ye, Yongjun; Yao, Xuanli; Luo, Liling] Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Ye, YJ ] U;Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.
关键词：
Radon exhalation rate;Adsorbing medium;CFD;Measurement method;Building foundation
摘要：
In radon pollution control, materials with radon adsorbing characteristics will significantly affect the migration and release of radon. In this paper, radon adsorbing medium (activated carbon particles) is proposed to be added to the building foundation granular filling layer as a radon adsorbing layer to alleviate indoor radon pollution. Radon exhalation rate is an important physical quantity used to evaluate the radon exhalation capacity of materials. This study compared the measurement results of radon exhalation rate on the radon adsorbing media surface by the traditional Closed-loop Method (CLM) and the Activated Carbon Purification Closed-loop Method (ACPCM) through experiments. The results show that the surface radon exhalation rate decrease rapidly due to the back diffusion effect of CLM, which seriously affects the measurement results. ACPCM can avoid the interference of back diffusion effect on the adsorption amount of radon adsorbing medium, obtaining reliable measurement results. In addition, the migration process of radon in the gas-solid medium and its interface during the measurement was simulated by computational fluid dynamics (CFD), and the measurement mechanism of the two methods was revealed. The research results can provide reference for the determination of radon exhalation rate on the radon adsorbing medium surface.
In radon pollution control, materials with radon adsorbing characteristics will significantly affect the migration and release of radon. In this paper, radon adsorbing medium (activated carbon particles) is proposed to be added to the building foundation granular filling layer as a radon adsorbing layer to alleviate indoor radon pollution. Radon exhalation rate is an important physical quantity used to evaluate the radon exhalation capacity of materials. This study compared the measurement results of radon exhalation rate on the radon adsorbing media surface by the traditional Closed-loop Method (CLM) and the Activated Carbon Purification Closed-loop Method (ACPCM) through experiments. The results show that the surface radon exhalation rate decrease rapidly due to the back diffusion effect of CLM, which seriously affects the measurement results. ACPCM can avoid the interference of back diffusion effect on the adsorption amount of radon adsorbing medium, obtaining reliable measurement results. In addition, the migration process of radon in the gas-solid medium and its interface during the measurement was simulated by computational fluid dynamics (CFD), and the measurement mechanism of the two methods was revealed. The research results can provide reference for the determination of radon exhalation rate on the radon adsorbing medium surface.
