摘要：
This study was conducted to investigate whether selected microbes with specific functions are comparable or even superior to indigenous consortium (IC) in the microbial uranium reduction process and to detect the immobilization mechanisms of U(VI) with different microbial consortia. Fe(III)-reducing bacteria (FeRB), sulfate-reducing bacteria (SRB) and nitrate-reducing bacteria (NRB) were employed to construct a designed consortium (DC), and the IC was obtained from natural samples. The results showed that the uranium-reducing ratio of the DC was higher (52.69%) than that of the IC (35.65%) after 34 days, although the uranium removal ratio with IC (98.75%) was slightly higher than that of the DC (95.75%). In both the DC and IC groups, uranium was first adsorbed onto the cell surface in the first few days, then sulfate and uranium were reduced simultaneously after depletion of nitrate, and finally labile U species transformed into stable form (e.g UO 2 ) over time. This work refined our understanding of the construction of highly efficient uranium-reducing microbes and provided insight into strengthening strategies for treating uranium-contaminated groundwater in situ .
This study was conducted to investigate whether selected microbes with specific functions are comparable or even superior to indigenous consortium (IC) in the microbial uranium reduction process and to detect the immobilization mechanisms of U(VI) with different microbial consortia. Fe(III)-reducing bacteria (FeRB), sulfate-reducing bacteria (SRB) and nitrate-reducing bacteria (NRB) were employed to construct a designed consortium (DC), and the IC was obtained from natural samples. The results showed that the uranium-reducing ratio of the DC was higher (52.69%) than that of the IC (35.65%) after 34 days, although the uranium removal ratio with IC (98.75%) was slightly higher than that of the DC (95.75%). In both the DC and IC groups, uranium was first adsorbed onto the cell surface in the first few days, then sulfate and uranium were reduced simultaneously after depletion of nitrate, and finally labile U species transformed into stable form (e.g UO 2 ) over time. This work refined our understanding of the construction of highly efficient uranium-reducing microbes and provided insight into strengthening strategies for treating uranium-contaminated groundwater in situ .
摘要：
This study aimed to reduce radon exhalation from coal fly ash-containing concrete bricks (CFA-containing concrete brick). A measurement device for determining the radon exhalation rate was designed and optimized. The device can control the temperature and humidity of the environment during the CFA-containing concrete bricks are measured. Two types of CFA-containing concrete bricks were designed in this study, and their radon exhalation rates were evaluated. (1) Sodium silicate (SS) and polyvinyl alcohol (PVA) were used as additives to fabricate CFA-containing concrete bricks to evaluate the radon inhibition performance of SS and PVA when applied to the concrete. (2) The original CFA-containing concrete bricks that had been cured for 28 days were pre-immersed in a saturated SS solution to evaluate the radon inhibition performance of the SS solution under different temperature and humidity conditions. The results showed that: (1) SS exhibited the best radon inhibition effect when used as an additive, achieving an inhibition rate of 52.95% at 35 degrees C and RH 72%. (2) SS also exhibited the good radon inhibition effect when applied through immersing, yielding an inhibition rate of 15.91% at 10 degrees C and RH 59%. (3) Incorporating SS as an additive into the concrete mixture was more effective in reducing the radon exhalation rate compared to immersing the CFA-containing concrete bricks in a saturated SS solution.
作者：
Ye, Yongjun;Yao, Xuanli;Chen, Daijia;Zhou, Ning
期刊：
Nuclear Engineering and Technology,2025年57(10):103691 ISSN：1738-5733
通讯作者：
Ye, YJ
作者机构：
[Ye, Yongjun; Yao, Xuanli; Zhou, Ning; Chen, Daijia] Univ South China, Sch Resources Environm & Safety Engn, 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] Univ South China, Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang 421001, 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：
Trackless Z -shaped filling stope;Numerical simulation;Air flow rate;Radon concentration;Adjustable air curtain
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.
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.
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.
摘要：
Acid in-situ leach uranium (U) mining layers (ML) characterized by anaerobic, oligotrophic conditions, high arsenic (As) concentration, represent an unique but poorly characterized microbial habitat. Herein, autotrophic microbial metabolisms and arsenic detoxification strategies in underground ML (depth >111 m) were revealed through 16S rRNA gene amplicon sequencing and metagenomic analysis. Dissolved organic matter (DOM) content in ML after acid in-situ leach mining was significantly higher than that in non-mining layers (NML). Compared with NML, the arsenite (As(III)) content in ML showed a decreasing trend, while the As(V) content correspondingly increased significantly. As(III) and DOM showed significant positive effects on the diversity of bacterial communities in ML and NML. The genes involved in Calvin Benson Bassham (CBB) pathway and monosaccharide decomposition dominated the DOM dynamics in ML and NML. Notably, metabolic pathway analyses demonstrated that microbial As(III) anaerobic oxidation by coupling with nitrate reduction favors CO 2 fixation driven by CBB pathway, reducing As toxicity and enhancing DOM content in ML. Chemolithoautotrophs utilize multiple survival strategies (e.g., nitrate assimilation, metals efflux) in ML. These findings reveal that chemolithoautotropic microbial As(III) oxidation contributes to CO 2 fixation and As detoxification in ML, broadening our horizons of As and carbon cycling in deep underground mining environments.
Acid in-situ leach uranium (U) mining layers (ML) characterized by anaerobic, oligotrophic conditions, high arsenic (As) concentration, represent an unique but poorly characterized microbial habitat. Herein, autotrophic microbial metabolisms and arsenic detoxification strategies in underground ML (depth >111 m) were revealed through 16S rRNA gene amplicon sequencing and metagenomic analysis. Dissolved organic matter (DOM) content in ML after acid in-situ leach mining was significantly higher than that in non-mining layers (NML). Compared with NML, the arsenite (As(III)) content in ML showed a decreasing trend, while the As(V) content correspondingly increased significantly. As(III) and DOM showed significant positive effects on the diversity of bacterial communities in ML and NML. The genes involved in Calvin Benson Bassham (CBB) pathway and monosaccharide decomposition dominated the DOM dynamics in ML and NML. Notably, metabolic pathway analyses demonstrated that microbial As(III) anaerobic oxidation by coupling with nitrate reduction favors CO 2 fixation driven by CBB pathway, reducing As toxicity and enhancing DOM content in ML. Chemolithoautotrophs utilize multiple survival strategies (e.g., nitrate assimilation, metals efflux) in ML. These findings reveal that chemolithoautotropic microbial As(III) oxidation contributes to CO 2 fixation and As detoxification in ML, broadening our horizons of As and carbon cycling in deep underground mining environments.
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.
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.
期刊：
Journal of Environmental Radioactivity,2025年287:107729 ISSN：0265-931X
通讯作者：
Ye, YJ
作者机构：
[Ye, Yongjun; Yao, Xuanli; Chen, Daijia] Univ South China, Sch Resources Environm & Safety Engn, 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; Hong, Yufei] Univ South China, Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang 421001, 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：
Active depressurization;CFD;Covered layer;Fracture;Radon;Radon exhalation rate
摘要：
In underground engineering, a covered layer is usually established to provide certain support and protection for underground tunnels. At the same time, the covered layer can also inhibit radon exhalation from surrounding rock. To study radon exhalation in the covered layer and surrounding rock of a tunnel, and to control radon migration in tunnels with fracture-pore covered layers, a specific underground tunnel was chosen for analysis. A radon migration and dynamics model in the fracture-pore medium was developed, and computational fluid dynamics (CFD) simulations were performed to analyze the radon exhalation from the covered layer and surrounding rock. The impact of factors like pressure difference, diffusion coefficient, and permeability on the radon exhalation rate was examined. The results indicated that adjusting these parameters could effectively manage the radon exhalation rate, with a particular focus on the proposed active depressurization (AD) method, which can significantly reduce the radon exhalation rate and provide scientific basis for radon pollution control in underground engineering.
In underground engineering, a covered layer is usually established to provide certain support and protection for underground tunnels. At the same time, the covered layer can also inhibit radon exhalation from surrounding rock. To study radon exhalation in the covered layer and surrounding rock of a tunnel, and to control radon migration in tunnels with fracture-pore covered layers, a specific underground tunnel was chosen for analysis. A radon migration and dynamics model in the fracture-pore medium was developed, and computational fluid dynamics (CFD) simulations were performed to analyze the radon exhalation from the covered layer and surrounding rock. The impact of factors like pressure difference, diffusion coefficient, and permeability on the radon exhalation rate was examined. The results indicated that adjusting these parameters could effectively manage the radon exhalation rate, with a particular focus on the proposed active depressurization (AD) method, which can significantly reduce the radon exhalation rate and provide scientific basis for radon pollution control in underground engineering.
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：
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.
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.
期刊：
Journal of Alloys and Compounds,2025年:183184 ISSN：0925-8388
通讯作者：
Le Li
作者机构：
[Lijie Chen; Xinyu Zhao; Guanghui Zhao; Zhongran Dai] Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, China;[Weilin Zhang] College of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, Hunan, China;[Le Li] 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：
[Le Li] K;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
摘要：
Designing high-performance photocatalytic semiconductor catalysts remains a formidable challenge in energy conversion and environmental remediation. This study develops three-dimensionally ordered mesoporous carbon nitride photonic crystals (CNPC) with synergistic nitrogen vacancies and inverse opal structures via a hard-templating method using nitrogen-rich precursors. Urea-derived CNPCU achieves 96.95% U(Ⅵ) removal after 60 min photoactivation followed by 3 h dark reaction, substantially outperforming unmodified UCN. Mechanistic studies reveal that photogenerated electrons reduce O 2 to ·O 2 - via a two-step single-electron pathway, which protonates to form H 2 O 2 . This species drives U(Ⅵ) reduction and subsequent precipitation as metastudtite ((UO 2 )O 2 ·2H 2 O), identified by XRD. Nitrogen vacancies optimize charge separation and generate active sites at the atomic level, while the microscale inverse opal structure enhances light harvesting via the slow-photon effect. Their synergistic interaction underpins such exceptional photocatalytic activity. The material demonstrates > 90% efficiency retention over 5 cycles and strong ion interference resistance, establishing a dual-scale engineering strategy for advanced metal-free photocatalysts.
Designing high-performance photocatalytic semiconductor catalysts remains a formidable challenge in energy conversion and environmental remediation. This study develops three-dimensionally ordered mesoporous carbon nitride photonic crystals (CNPC) with synergistic nitrogen vacancies and inverse opal structures via a hard-templating method using nitrogen-rich precursors. Urea-derived CNPCU achieves 96.95% U(Ⅵ) removal after 60 min photoactivation followed by 3 h dark reaction, substantially outperforming unmodified UCN. Mechanistic studies reveal that photogenerated electrons reduce O 2 to ·O 2 - via a two-step single-electron pathway, which protonates to form H 2 O 2 . This species drives U(Ⅵ) reduction and subsequent precipitation as metastudtite ((UO 2 )O 2 ·2H 2 O), identified by XRD. Nitrogen vacancies optimize charge separation and generate active sites at the atomic level, while the microscale inverse opal structure enhances light harvesting via the slow-photon effect. Their synergistic interaction underpins such exceptional photocatalytic activity. The material demonstrates > 90% efficiency retention over 5 cycles and strong ion interference resistance, establishing a dual-scale engineering strategy for advanced metal-free photocatalysts.
摘要：
Hydrogel materials have emerged as promising candidates for uranium-contaminated water remediation, yet the interrelationship between their hydration properties (moisture content/swelling ratio) and sorption performance remains insufficiently explored. This study synthesized a novel hydrogel (HLSs/PAM gel) using humic-like substances (HLSs) derived from spent coffee grounds and acrylamide (AM) monomer, aiming to elucidate the effects of environmental parameters on both swelling behavior and U(VI) sorption performance. Multivariate experiments results demonstrated that pH exerted a minimal impact on the swelling behavior of HLSs/PAM gel, while showed a predominant influence on sorption performance. Meanwhile, the sorption performance of U(VI) by HLSs/PAM gel showed a strong correlation with the pH value and concentration of U(VI), and the correlation between sorption performance of U(VI) and reaction time was particularly evident at concentrations exceeding 20 mg/L. These findings reveals that hydrogel structural adaptability and chemical affinity outweigh physical swelling characteristics in governing U(VI) sequestration, and which can provide critical insights for optimizing hydrogel design in radioactive wastewater treatment.
Hydrogel materials have emerged as promising candidates for uranium-contaminated water remediation, yet the interrelationship between their hydration properties (moisture content/swelling ratio) and sorption performance remains insufficiently explored. This study synthesized a novel hydrogel (HLSs/PAM gel) using humic-like substances (HLSs) derived from spent coffee grounds and acrylamide (AM) monomer, aiming to elucidate the effects of environmental parameters on both swelling behavior and U(VI) sorption performance. Multivariate experiments results demonstrated that pH exerted a minimal impact on the swelling behavior of HLSs/PAM gel, while showed a predominant influence on sorption performance. Meanwhile, the sorption performance of U(VI) by HLSs/PAM gel showed a strong correlation with the pH value and concentration of U(VI), and the correlation between sorption performance of U(VI) and reaction time was particularly evident at concentrations exceeding 20 mg/L. These findings reveals that hydrogel structural adaptability and chemical affinity outweigh physical swelling characteristics in governing U(VI) sequestration, and which can provide critical insights for optimizing hydrogel design in radioactive wastewater treatment.
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 Sscheme 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 & sdot;O2/H2O2. These species subsequently interact with U(VI), resulting in the precipitation of (UO2)O2 & sdot;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.
作者：
Ye, Yongjun;Hong, Yufei;Shang, Shanwei;Yao, Xuanli
期刊：
Journal of Environmental Radioactivity,2025年289:107747 ISSN：0265-931X
通讯作者：
Ye, YJ
作者机构：
[Ye, Yongjun; Hong, Yufei] 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; Shang, Shanwei; Yao, Xuanli] Univ South China, Sch Resources Environm & Safety Engn, 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：
Multi-field coupling;Numerical simulation;Radon exhalation rate;Radon migration-seepage;Underground Construction
摘要：
With the increasing demand for uranium resource development and the gradual deepening of mining, radon pollution has become a significant issue in underground mines. This study aims to investigate the effects of temperature, humidity, ventilation pressure, and rock stress on radon migration in roadway surrounding rocks using Computational Fluid Dynamics (CFD) combined with a heat-moisture-force coupling model. The results show that the pressure difference on the roadway wall is positively correlated with the radon exhalation rate, while an increase in inlet air speed leads to a decrease in the exhalation rate. Among environmental factors, temperature exhibits a more pronounced impact on radon exhalation rate compared to humidity, especially due to stress and temperature changes after roadway excavation. The study also reveals that deepening the roadway and increasing surrounding rock temperature and stress further enhance radon exhalation. These findings highlight the critical role of ventilation and environmental factors in controlling radon concentrations in underground spaces, providing a theoretical foundation for future research on radon migration in deep underground environments.
With the increasing demand for uranium resource development and the gradual deepening of mining, radon pollution has become a significant issue in underground mines. This study aims to investigate the effects of temperature, humidity, ventilation pressure, and rock stress on radon migration in roadway surrounding rocks using Computational Fluid Dynamics (CFD) combined with a heat-moisture-force coupling model. The results show that the pressure difference on the roadway wall is positively correlated with the radon exhalation rate, while an increase in inlet air speed leads to a decrease in the exhalation rate. Among environmental factors, temperature exhibits a more pronounced impact on radon exhalation rate compared to humidity, especially due to stress and temperature changes after roadway excavation. The study also reveals that deepening the roadway and increasing surrounding rock temperature and stress further enhance radon exhalation. These findings highlight the critical role of ventilation and environmental factors in controlling radon concentrations in underground spaces, providing a theoretical foundation for future research on radon migration in deep underground environments.
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：
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.
