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.
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：
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.
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.
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.
期刊：
Journal of Radioanalytical and Nuclear Chemistry,2025年:1-18 ISSN：0236-5731
通讯作者：
Xie, SB
作者机构：
[Shi, Nijing; Ma, Xiangxiang; Xie, Shuibo] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.;[Xie, Shuibo] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, 28 Changshen Rd, Hengyang 421001, Peoples R China.
通讯机构：
[Xie, SB ] U;Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, 28 Changshen Rd, Hengyang 421001, Peoples R China.
关键词：
Magnetic attapulgite;3-aminopropyltriethoxysilane;Uranium(VI);Tetracycline
摘要：
ATP-Fe3O4-APTES (AFAS), was synthesized by modifying magnetic attapulgite with 3-aminopropyltriethoxysilane to remove U(VI) and tetracycline (TC) from medical wastewater. In a single-component system, the maximum adsorption capacities of AFAS for U(VI) were 298.87 mg/g and tetracycline were 111.71 mg/g, respectively. Synergistic effect instead of competitive adsorption occurred between U(VI) and TC under the combined binary system, with the complexation interactions between the U(VI) and TC. U(VI) adsorption mechanisms on AFAS (e.g. precipitation, ion exchange and complexation) are different from the tetracycline (e.g. hydrogen bonding and pi-pi interactions). After five recycling cycles, AFAS maintained over 75% removal efficiency for both pollutants in the binary system.
摘要：
Organic matter retained by reactive minerals constitutes an essential mechanism for long-term storage of carbon in soil, a process that is governed by climate factors. However, how the reactive mineral-associated organic matter affects the composition of soil dissolved organic matter (DOM) across a broad range of climates remains unclear. In this study, the contents of reactive minerals and their associated organic matter were determined by the chemical extraction method. Moreover, the effects of organic matter retained by reactive minerals on soil DOM composition were investigated at molecular level across a wide environmental gradient, by employing Fourier transform ion cyclotron resonance mass spectrometry, solid-state 13 C nuclear magnetic resonance and statistical analyses. The results of FT-ICR-MS and correlation analyses indicated that the relative abundances of carbohydrates and proteins/amino sugars decreased, while the relative abundance of condensed aromatics increased with the increase of the content of organic matter retained by reactive minerals per unit mass (i.e., (OC) RN ) in soils. We highlighted that the adsorption and dissolution processes of DOM molecules, especially aromatic molecules, on reactive minerals played crucial roles in regulating the molecular composition of DOM in soil solution. Furthermore, (OC) RN was controlled by climate-driven chemical weathering (e.g., precipitation). Our results imply that (OC) RN is a key variable for regulating soil DOM composition under the impacts of climates, and can be used in developing prediction models for carbon cycling.
Organic matter retained by reactive minerals constitutes an essential mechanism for long-term storage of carbon in soil, a process that is governed by climate factors. However, how the reactive mineral-associated organic matter affects the composition of soil dissolved organic matter (DOM) across a broad range of climates remains unclear. In this study, the contents of reactive minerals and their associated organic matter were determined by the chemical extraction method. Moreover, the effects of organic matter retained by reactive minerals on soil DOM composition were investigated at molecular level across a wide environmental gradient, by employing Fourier transform ion cyclotron resonance mass spectrometry, solid-state 13 C nuclear magnetic resonance and statistical analyses. The results of FT-ICR-MS and correlation analyses indicated that the relative abundances of carbohydrates and proteins/amino sugars decreased, while the relative abundance of condensed aromatics increased with the increase of the content of organic matter retained by reactive minerals per unit mass (i.e., (OC) RN ) in soils. We highlighted that the adsorption and dissolution processes of DOM molecules, especially aromatic molecules, on reactive minerals played crucial roles in regulating the molecular composition of DOM in soil solution. Furthermore, (OC) RN was controlled by climate-driven chemical weathering (e.g., precipitation). Our results imply that (OC) RN is a key variable for regulating soil DOM composition under the impacts of climates, and can be used in developing prediction models for carbon cycling.
摘要：
The efficient extraction of uranium from acid mining wastewater remains a significant challenge. In this study, a novel phospho-enriched polyamidoxime/alginate (PA/PAO/SA) gel beads was fabricated through a one-pot self-assembly method with calcium ions for crosslinking and used for efficient extraction of U(VI). Drawing on abundant functional groups, the PA/PAO/SA gel beads exhibited remarkable uranium extraction performance in acidic uranium-containing wastewater within the pH range of 2.5–5.5, and the removal rate of a 20 mg/L uranium-containing solution was nearly 100 % and it showed great selectivity ( K d = 1.9 L/g) at pH 4.0. The data of U(VI) adsorption fit well with the Langmuir isothermal adsorption and the quasi-second-order kinetic model, which indicates the adsorption behavior of PA/PAO/SA gel beads for U(VI) pertains to single layer chemisorption. Notably, PA/PAO/SA gel beads display excellent mechanical properties and stability, and the removal rate of U(VI) by PA/PAO/SA gel beads only a 3.86 % decrease after 10 consecutive adsorption–desorption cycles. The results of dynamic fixed-bed column experiment showed that the PA/PAO/SA gel beads can reduce the U(VI) concentration of the actual acidic uranium-containing wastewater with a volume of 600 bed volumes (BV) to below the national discharge standard (GB 23727–2020), and the adsorbed uranium can be completely desorbed with only 60 BV of eluent. Mechanism studies conducted through characterization and DFT calculations unveil that the synergistic effects of electrostatic, coordination and ion exchange endow PA/PAO/SA gel beads with excellent selective adsorption properties for U(VI). This study provides a promising adsorption material and strategy for the efficient extraction of uranium from acidic nuclear wastewater.
The efficient extraction of uranium from acid mining wastewater remains a significant challenge. In this study, a novel phospho-enriched polyamidoxime/alginate (PA/PAO/SA) gel beads was fabricated through a one-pot self-assembly method with calcium ions for crosslinking and used for efficient extraction of U(VI). Drawing on abundant functional groups, the PA/PAO/SA gel beads exhibited remarkable uranium extraction performance in acidic uranium-containing wastewater within the pH range of 2.5–5.5, and the removal rate of a 20 mg/L uranium-containing solution was nearly 100 % and it showed great selectivity ( K d = 1.9 L/g) at pH 4.0. The data of U(VI) adsorption fit well with the Langmuir isothermal adsorption and the quasi-second-order kinetic model, which indicates the adsorption behavior of PA/PAO/SA gel beads for U(VI) pertains to single layer chemisorption. Notably, PA/PAO/SA gel beads display excellent mechanical properties and stability, and the removal rate of U(VI) by PA/PAO/SA gel beads only a 3.86 % decrease after 10 consecutive adsorption–desorption cycles. The results of dynamic fixed-bed column experiment showed that the PA/PAO/SA gel beads can reduce the U(VI) concentration of the actual acidic uranium-containing wastewater with a volume of 600 bed volumes (BV) to below the national discharge standard (GB 23727–2020), and the adsorbed uranium can be completely desorbed with only 60 BV of eluent. Mechanism studies conducted through characterization and DFT calculations unveil that the synergistic effects of electrostatic, coordination and ion exchange endow PA/PAO/SA gel beads with excellent selective adsorption properties for U(VI). This study provides a promising adsorption material and strategy for the efficient extraction of uranium from acidic nuclear wastewater.
摘要：
The average radon exhalation rate of the building wall surface is a key factor affecting indoor radon concentration, and its accurate measurement is of great significance for the evaluation and design of radon protection for walls. The main layer of the masonry walls is composed of bricks and bonded cement mortar. Due to the possible differences in radon exhalation rates from brick surfaces and cement mortar joints. General methods for measuring radon exhalation rate of the wall (such as the closed-loop method, the opened-loop method and the local static collection method) all involve the use of radon collection hoods. However, the measurement results of radon exhalation rate are significantly affected by the position and size of the radon collection hood covering the wall surface. Therefore, the Computational Fluid Dynamics (CFD) method was used to study the radon exhalation rules on the surface of masonry wall under diffusion and seepage-diffusion conditions, respectively. The simulation results show that the radon exhalation rates on the brick surfaces and cement mortar joints of masonry walls are different, and a representative elementary surface (RES) should be selected when accurately measuring the radon exhalation rate of the wall surface. It is worth noting that the shape of the RES is not restricted, and the representative surface for measuring radon exhalation rate is not unique; it can be an integer multiple surface of RES area. Furthermore, experiments have confirmed the accuracy and effectiveness of the determined RES. The proposed RES achieves accurate measurement of the average radon exhalation rate of walls by integrating the radon exhalation rates at the joints between bricks and cement mortar.
The average radon exhalation rate of the building wall surface is a key factor affecting indoor radon concentration, and its accurate measurement is of great significance for the evaluation and design of radon protection for walls. The main layer of the masonry walls is composed of bricks and bonded cement mortar. Due to the possible differences in radon exhalation rates from brick surfaces and cement mortar joints. General methods for measuring radon exhalation rate of the wall (such as the closed-loop method, the opened-loop method and the local static collection method) all involve the use of radon collection hoods. However, the measurement results of radon exhalation rate are significantly affected by the position and size of the radon collection hood covering the wall surface. Therefore, the Computational Fluid Dynamics (CFD) method was used to study the radon exhalation rules on the surface of masonry wall under diffusion and seepage-diffusion conditions, respectively. The simulation results show that the radon exhalation rates on the brick surfaces and cement mortar joints of masonry walls are different, and a representative elementary surface (RES) should be selected when accurately measuring the radon exhalation rate of the wall surface. It is worth noting that the shape of the RES is not restricted, and the representative surface for measuring radon exhalation rate is not unique; it can be an integer multiple surface of RES area. Furthermore, experiments have confirmed the accuracy and effectiveness of the determined RES. The proposed RES achieves accurate measurement of the average radon exhalation rate of walls by integrating the radon exhalation rates at the joints between bricks and cement mortar.
通讯机构：
[Ding, Y ] 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：
DOM oxidation;Dissolved organic matter;Iron (oxyhydr)oxides;Mn oxides;Mn(II) oxidation
摘要：
The abiotic oxidation of divalent manganese (Mn(II)) and the formation of Mn oxides are important geochemical processes, which control the mobility and availability of Mn as well as element cycling and pollutant behavior in soils. It was found that iron (oxyhydr)oxides can catalyze Mn(II) oxidation, but the effects of the coexisting dissolved organic matter (DOM) molecules on the catalysis of different iron (oxyhydr)oxides for Mn(II) oxidation are poorly understood. Herein, we investigated Mn(II) oxidation under the impacts of the interactions between iron (oxyhydr)oxides (i.e., ferrihydrite, goethite and hematite) and DOM molecules. Simultaneously, we elucidated the variations of DOM composition and properties. Our results indicated that the catalysis of iron (oxyhydr)oxides for Mn(II) oxidation was significantly inhibited by DOM. Moreover, DOM had less inhibiting effect on the catalysis of ferrihydrite for Mn(II) oxidation and the formation of Mn oxides (e.g., hausmannite and buserite) relative to goethite and hematite, which was partially because of the higher electron transfer capacities of ferrihydrite. Meanwhile, DOM molecules with high nominal oxidation state of carbon (NOSC), molecular weight, unsaturation and aromaticity were selectively adsorbed and oxidized by Mn oxides, including the oxygenated phenols and polyphenols. The newly formed molecules mainly belonged to phenols depleted of oxygen and aliphatics. Furthermore, NOSC was a key molecular characteristic for controlling DOM composition during DOM adsorption and oxidation by Mn oxides when iron minerals were present. Overall, our research contributes to understanding Mn(II) oxidation mechanisms under heterogeneous systems and behaviors of DOM molecules in the environment.
The abiotic oxidation of divalent manganese (Mn(II)) and the formation of Mn oxides are important geochemical processes, which control the mobility and availability of Mn as well as element cycling and pollutant behavior in soils. It was found that iron (oxyhydr)oxides can catalyze Mn(II) oxidation, but the effects of the coexisting dissolved organic matter (DOM) molecules on the catalysis of different iron (oxyhydr)oxides for Mn(II) oxidation are poorly understood. Herein, we investigated Mn(II) oxidation under the impacts of the interactions between iron (oxyhydr)oxides (i.e., ferrihydrite, goethite and hematite) and DOM molecules. Simultaneously, we elucidated the variations of DOM composition and properties. Our results indicated that the catalysis of iron (oxyhydr)oxides for Mn(II) oxidation was significantly inhibited by DOM. Moreover, DOM had less inhibiting effect on the catalysis of ferrihydrite for Mn(II) oxidation and the formation of Mn oxides (e.g., hausmannite and buserite) relative to goethite and hematite, which was partially because of the higher electron transfer capacities of ferrihydrite. Meanwhile, DOM molecules with high nominal oxidation state of carbon (NOSC), molecular weight, unsaturation and aromaticity were selectively adsorbed and oxidized by Mn oxides, including the oxygenated phenols and polyphenols. The newly formed molecules mainly belonged to phenols depleted of oxygen and aliphatics. Furthermore, NOSC was a key molecular characteristic for controlling DOM composition during DOM adsorption and oxidation by Mn oxides when iron minerals were present. Overall, our research contributes to understanding Mn(II) oxidation mechanisms under heterogeneous systems and behaviors of DOM molecules in the environment.
