Applied Clay Science最新文献

Layered zinc hydroxide–dipeptide hybrid integrated into silk-based 3D scaffolds aiming for biomedical applications 层状氢氧化锌-二肽杂化物集成到丝基3D支架中，旨在用于生物医学应用

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-12 DOI: 10.1016/j.clay.2025.108087

Denise Eulálio , Mariana Pires Figueiredo , Simone S. Silva , Luísa C. Rodrigues , Emanuel M. Fernandes , Albino Martins , Albina Franco , Diana Soares da Costa , Richard Landers , Fabrice Leroux , Christine Taviot-Gueho , Dalva Lúcia Araújo de Faria , Rui L. Reis , Vera Regina Leopoldo Constantino

Zinc ions and N-acetylcysteine (NAC) are bioactive agents with key physiological roles. When associated with biomacromolecules such as silk fibroin (SF), they offer a promising pathway for advanced biomedical applications. This study reports the synthesis of layered zinc hydroxide (LZH) intercalated with NAC as well as the development of LZH-NAC/SF scaffolds. The synthesis of LZH-NAC was conducted using a constant-pH method, and experimental parameters were controlled to obtain a monophasic LZH. Comprehensive structural, spectroscopic, textural, and thermal characterisation confirmed the successful intercalation of NAC into the LZH. The employed methodology enabled the production of an LZH-NAC nanomaterial with an encapsulation efficiency of approximately 80 % by mass and a loading capacity of around 30 %. To evaluate its biomedical potential, LZH-NAC/SF 3D composite scaffolds were prepared by dispersing LZH-NAC in SF solution, followed by freezing and freeze-drying. The average pore sizes observed in the scaffolds ranged from 75 to 87 μm, and the swelling capacity was approximately 1700 % after incubation in phosphate-buffered saline (pH 7.4). Cytocompatibility assays revealed that LZH-NAC/SF scaffolds supported cell viability at a zinc concentration of 0.189 mg/mL, similar to that of the SF and NAC/SF scaffolds. These results underscore the potential of LZH-NAC/SF scaffolds as multifunctional biomaterials for the controlled delivery of therapeutic agents, with significant implications for tissue engineering and drug delivery systems.

锌离子和n -乙酰半胱氨酸（NAC）是具有重要生理作用的生物活性物质。当与生物大分子如丝素蛋白（SF）相结合时，它们为先进的生物医学应用提供了一条有希望的途径。本研究报道了层状氢氧化锌（LZH）嵌入NAC的合成及LZH-NAC/SF支架的研制。采用恒ph法合成LZH- nac，并对实验参数进行控制，得到单相LZH。综合结构、光谱、织构和热表征证实了NAC成功嵌入LZH。所采用的方法能够生产出LZH-NAC纳米材料，其包封效率约为80%，负载能力约为30%。为了评估其生物医学潜力，我们将LZH-NAC分散在SF溶液中，然后进行冷冻和冷冻干燥，制备LZH-NAC/SF 3D复合支架。在磷酸盐缓冲盐水（pH 7.4）中孵育后，支架的平均孔径为75 ~ 87 μm，膨胀容量约为1700%。细胞相容性实验表明，在锌浓度为0.189 mg/mL时，LZH-NAC/SF支架支持细胞活力，与SF和NAC/SF支架相似。这些结果强调了LZH-NAC/SF支架作为治疗药物控制递送的多功能生物材料的潜力，对组织工程和药物递送系统具有重要意义。

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引用次数: 0

Retrospective of chrysotile synthesis: From tough geoinspired process up to soft chemical design 温石棉合成回顾：从坚硬的土工工艺到柔软的化学设计

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-12 DOI: 10.1016/j.clay.2025.108088

Andrea Bloise , Ilaria Fuoco , Carmine Apollaro , Giovanni Vespasiano , Ekaterina Khrapova , Andrei Krasilin

Chrysotile, the fibrous form of serpentine, is characterized by the chemical formula Mg₃Si₂O₅(OH)₄. Over the past seventy years, significant research has focused on synthesizing chrysotile, initially for petrological studies and more recently for applications in nanotechnology, particularly high-purity chrysotile nanotubes and doped variants. Common synthesis methods involve hydrothermal reactions using cristobalite and periclase or magnesium hydroxide and silica gel mixtures. Most frequently used synthesis conditions generally include temperatures between 200 °C and 400 °C and pressures from 0.5 to 100 MPa, though these often result in impure chrysotile with unwanted phases. Despite the promise of doped chrysotile, natural fibers are often unsuitable for nanoscience due to foreign ions and mineral intergrowths. Recent studies explore the potential for creating isomorphic series as Mg₃Si₂O₅(OH)₄ – Ni₃Si₂O₅(OH)₄ or Mg₃Si₂O₅(OH)₄ - (Fe²⁺, Fe³⁺)_3-2Si₂O₅(OH)₄, examining the impact of nickel and iron on chrysotile's properties. This study provides a review of the reported synthesis methods for chrysotile, emphasizing the synthesis techniques, precursor materials, and the resulting crystal chemistry. The findings highlight the dynamic nature of chrysotile synthesis research, with implications for materials science, including the development of novel nanostructures and environmental remediation technologies.

温石棉是蛇纹石的纤维状结构，其化学特征为：Mg3Si2O5(OH)4。在过去的七十年里，重要的研究集中在温石棉的合成上，最初用于岩石学研究，最近用于纳米技术的应用，特别是高纯度的温石棉纳米管和掺杂变体。常用的合成方法包括用方英石和方长石或氢氧化镁和硅胶混合物进行水热反应。最常用的合成条件通常包括温度在200°C到400°C之间，压力在0.5到100 MPa之间，尽管这些条件通常会导致含有不需要相的不纯温石棉。尽管掺温石棉很有前途，但由于外来离子和矿物的共生，天然纤维往往不适合用于纳米科学。最近的研究探索了创建Mg3Si2O5(OH)4 - Ni3Si2O5(OH)4或Mg3Si2O5(OH)4 - (Fe2+, Fe3+)3-2Si2O5(OH)4等同构系列的潜力，研究了镍和铁对温sotile性能的影响。本文综述了温石棉的合成方法，重点介绍了合成技术、前驱体材料和所得晶体化学性质。这些发现突出了温石棉合成研究的动态性质，对材料科学，包括新型纳米结构和环境修复技术的发展具有重要意义。

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引用次数: 0

Five-year thermo-hydro-mechanical and chemical evolution of compacted bentonite: reactive transport 五年压实膨润土的热-水-力学和化学演化：反应性输运

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-10 DOI: 10.1016/j.clay.2025.108086

María Victoria Villar , Andrés Idiart , Emilie Coene , Jaime Cuevas , Ana María Melón , Ana I. Ruiz , Almudena Ortega , Ville Heino

To help describing and understanding the mechanisms and factors governing the geochemical evolution and mineralogical alteration of compacted bentonite under hydraulic and thermal gradients similar to those experienced by engineered barriers in radioactive waste repositories, an experimental and modelling programme was carried out. Six thermo-hydraulic tests were performed in cylindrical cells (10 × 10 cm) using compacted Wyoming-type bentonite. The bottom of the cells was initially heated at 90 °C and once hydraulic equilibrium was reached, hydration of the bentonite started through the top surface for different periods of time (1, 2.5 and 5 years). The top surface was maintained at 20 °C during the whole test duration to induce a thermal gradient. The composition of the hydration water reproduced, for half of the cells, that of a saline groundwater and for the other half, of a dilute glacial water. The temperature of the heater was increased to 110 °C after ∼1 year of hydration. At termination, the bentonite was characterised. The thermo-hydraulic evolution during operation, final state of the bentonite and its mineralogical changes were simulated with a thermo-hydro-chemical model and reported in a companion paper.

Hydration brought about dissolution of calcite and gypsum, partial substitution of exchangeable sodium by calcium in the interlayer and transport of solutes towards hotter areas, where they precipitated as anhydrite and halite when saline water was used. In the longer term, the concentration gradient prompted the diffusive transport of chloride. The cation exchange capacity did not change over time, confirming the lack of changes in the montmorillonite crystal-chemistry that the mineralogical analyses had shown. The smectite interlayer composition kept its predominant monovalent character, although the exchangeable magnesium and potassium increased transitorily towards the heater while the bentonite remained unsaturated. The patterns observed were the same irrespective of the kind of water used, but the processes were enhanced with saline water.

为了帮助描述和理解控制压实膨润土在水力和热梯度下的地球化学演化和矿物学变化的机制和因素，类似于放射性废物处置库中工程屏障所经历的情况，开展了一项实验和建模计划。采用压实的怀俄明型膨润土在圆柱形池（10 × 10 cm）中进行了6次热水力试验。细胞底部最初在90°C下加热，一旦达到水力平衡，膨润土的水化作用开始通过顶部表面，持续不同的时间（1年、2.5年和5年）。在整个测试期间，顶部表面保持在20°C，以诱导热梯度。水合水的成分，对一半的细胞来说，是盐水的地下水，对另一半来说，是稀释的冰川水。在水化1年后，加热器的温度升高到110°C。终止时，对膨润土进行了表征。利用热-水-化学模型模拟了膨润土运行过程中的热-水演化过程、膨润土的最终状态及其矿物学变化，并在相应的论文中报道。水合作用导致方解石和石膏溶解，层间钙部分取代了可交换性钠，溶质向较热的地区迁移，当使用盐水时，溶质以硬石膏和盐石的形式沉淀。长期来看，浓度梯度促进了氯离子的扩散输运。阳离子交换容量没有随着时间的推移而改变，证实了矿物学分析所显示的蒙脱土晶体化学没有变化。蒙脱石层间组成保持了其主要的单价特征，但可交换性镁和钾向加热器短暂增加，而膨润土仍保持不饱和。无论使用哪种水，观察到的模式都是相同的，但盐水增强了这一过程。

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引用次数: 0

Quarry waste clays as supplementary cementitious materials: Mineralogical evolution and pozzolanic performance after thermal activation 作为补充胶凝材料的采石场废粘土：热活化后的矿物学演化和火山灰性能

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-06 DOI: 10.1016/j.clay.2025.108085

Erdi Avci , Elif Sidimi , Nana Asaam , Aysu Dag , Atiye Tugrul , Priyadharshini Perumal

This study investigates the potential of thermally activated quarry waste as alternative supplementary cementitious materials (SCMs) for sustainable binder systems. Three clay-rich materials were collected from a sand quarry located on the European side of Istanbul: two natural overburden clays (Yellow Layer-YL and Blue Layer-BL) and one process-derived sludge waste (TA) generated during sand washing. All samples were sieved (<150 μm), dried, and calcined at 800 °C for 2 h. Mineralogical (XRD), chemical (XRF), and thermal (TG, FTIR) analyses were conducted to evaluate phase transformation and amorphous phase development. Pozzolanic reactivity was assessed by the R³ test, including heat release and bound water measurements. Results showed that the TA sample exhibited the highest reactivity due to its kaolinite content and fine, homogeneous particle structure. In contrast, the BL sample demonstrated limited reactivity owing to the dominance of thermally stable phases such as muscovite and albite. Mortar specimens prepared with 20 % SCM replacement were tested for compressive strength at 7, 14, and 28 days using both CEM I and CEM II binders. The TA-C mixture achieved a compressive strength index (CSI) of 102.9 % with CEM I at 14 days, indicating strong early-age performance, while YL-C showed the highest 28-day strength with CEM II (CSI = 97.9 %). These findings confirm that sludge-based SCMs, when properly activated, can match or even exceed the performance of conventional systems, offering a viable strategy for resource-efficient and low-carbon cementitious materials.

本研究探讨了热活化采石场废物作为可持续粘合剂系统替代补充胶凝材料（scm）的潜力。从位于伊斯坦布尔欧洲一侧的采石场收集了三种富含粘土的材料：两种天然覆盖层粘土（黄色层- yl和蓝色层- bl）和一种在洗砂过程中产生的工艺污泥废物（TA）。所有样品经过筛分（<150 μm），干燥，并在800°C下煅烧2小时。进行矿物（XRD），化学（XRF）和热（TG， FTIR）分析以评估相变和非晶相的发展。通过R3测试评估火山灰的反应性，包括热量释放和结合水测量。结果表明，TA样品高岭石含量高，颗粒结构细小均匀，反应活性最高。相比之下，由于白云母和钠长石等热稳定相的优势，BL样品表现出有限的反应性。使用CEM I和CEM II粘结剂，在7、14和28天测试用20% SCM替代的砂浆试件的抗压强度。TA-C混合物的抗压强度指数（CSI）在14天达到102.9%，显示出较强的早期性能，而YL-C混合物在28天的抗压强度最高（CSI = 97.9%）。这些研究结果证实，当适当激活时，基于污泥的SCMs可以匹配甚至超过传统系统的性能，为资源高效和低碳胶凝材料提供了可行的策略。

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引用次数: 0

Essential oil-loaded amine-modified HNTs composites for sustained release and enhanced antibacterial performance in root rot control 精油载胺改性HNTs复合材料缓释及增强根腐病防治抗菌性能

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-05 DOI: 10.1016/j.clay.2025.108066

Guixiang Teng , Hui Yao , Hongyu Wang , Shuting Zhang , Yanzan Meng , Meng Zhao , Yan Yang , Chun Zhang

To mitigate the detrimental effects of root rot disease on Chinese herbal medicines, this study developed an environmentally friendly sustained-release antimicrobial system (CEO@HNTs-NH₂) based on clove essential oil (CEO) loaded onto amino-functionalized Halloysite nanotubes (HNTs-NH₂). Characterization results revealed that CEO@HNTs-NH₂ enhanced the thermal stability of CEO and significantly strengthened their interaction. Density Functional Theory (DFT) calculations demonstrated negative values for both the adsorption energy (−0.5772 eV) and interaction energy (−0.2117 eV) of CEO@HNTs-NH₂, providing molecular-level insights into the sustained-release mechanism. The release studies demonstrated a significantly low cumulative release of 21.20 ± 0.43 % over 10 days, exhibiting Fickian diffusion kinetics (R² = 0.99). This controlled release profile effectively mitigates the inherent volatility of CEO. Innovatively, we fabricated HAK clay tablets by compounding CEO@HNTs-NH₂ with Attapulgite and Kaolin—serving as structural supporter and coating agent, respectively—at an optimal 3:2:2 ratio. The tablet formulation conditions were optimized by Box-Behnken Design, yielding the optimal parameters: molding temperature of 30 °C, pressure of 0.86 MPa, and holding time of 32 min. Finally, the pot experiments demonstrated that HAK tablets significantly reduced the plant disease severity of Rehmannia by 59.8 % (Prevention group) and 32.2 % (Treatment group) compared to the Pathogenic group, confirming their potentially antimicrobial efficacy. In summary, this clay mineral nanocomposite system achieves controlled release through synergistic physico-chemical interactions, offering an innovative strategy for the application of clay minerals in sustainable agriculture.

为了减轻根腐病对中草药的有害影响，本研究开发了一种环境友好型缓释抗菌系统（CEO@HNTs-NH2），该系统基于丁香精油（CEO）负载在氨基功能化埃洛石纳米管（HNTs-NH2）上。表征结果表明CEO@HNTs-NH2增强了CEO的热稳定性，显著增强了它们之间的相互作用。密度泛函理论（DFT）计算表明CEO@HNTs-NH2的吸附能（- 0.5772 eV）和相互作用能（- 0.2117 eV）均为负值，为分子水平上的缓释机制提供了深入的了解。释放试验表明，10 d内的累积释放量为21.20±0.43%，符合菲克扩散动力学（R2 = 0.99）。这种受控的发布配置文件有效地减轻了CEO固有的不稳定性。我们创新地将CEO@HNTs-NH2与凹凸棒土和高岭土（分别作为结构载体和包衣剂）以3:2:2的最佳比例复配制成HAK粘土片。采用Box-Behnken设计法对片剂的处方条件进行优化，得到最佳工艺参数：成型温度30℃，压力0.86 MPa，保温时间32 min。最后，盆栽实验表明，与致病组相比，HAK片显著降低了地黄植物病害严重程度，分别降低了59.8%（预防组）和32.2%（治疗组），证实了其潜在的抗菌作用。综上所述，该黏土矿物纳米复合体系通过物理化学协同作用实现控释，为黏土矿物在可持续农业中的应用提供了一种创新策略。

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引用次数: 0

Evolution of steel-bentonite interactions under hydrothermal gradients: Mineralogical and geochemical implications for nuclear waste disposal 热液梯度下钢-膨润土相互作用的演化：核废料处理的矿物学和地球化学意义

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-05 DOI: 10.1016/j.clay.2025.108084

Carlos Mota-Heredia, Jaime Cuevas, Raúl Fernández

Carbon steel and bentonite are chosen as engineered barriers for high-level radioactive waste containment in deep geological repositories, which requires an evaluation of their long-term interactions to ensure durability. Two laboratory experiments were conducted under hydrothermal gradients with steel-Ca-Mg-Na-bentonite and Na-bentonite unsaturated columns over 25 and 27 months, respectively. The experiments measured changes in the porewater distribution, the specific surface area, the cation exchange capacity of the bentonites, and the oxidation state of Fe. These were determined in different sections along the columns. Mineralogical analyses were performed using X-ray diffraction and scanning electron microscopy. The results obtained showed water saturation at the conclusion of the experimental time. The specific surface area of bentonites decreased near the steel interface, while the cation exchange capacity exhibited an overall increase. The corrosion rate decreased over time, with bentonite showing enriched Fe content within the first 3.5 mm from the steel interface. New Fe-bearing minerals, including ferri-chlorite, magnetite, hematite, maghemite, and siderite, were identified as reaction products at the steel-bentonite interface. Aqueous species are redistributed in the bentonite's porewater, increasing with time the concentrations of Na⁺, Ca²⁺, Mg²⁺ and SO₄²⁻ and decreasing those of Fe, due to the imposed hydraulic gradient and the precipitation reactions. This study compares the evolution of these bentonite properties with a previous study at short experimental times of 1 and 6 months of reaction. These findings are relevant to deep geological disposal conditions, where bentonite influences the formation and nature of iron clay minerals over time.

选择碳钢和膨润土作为深层地质储存库中高放射性废物围堵的工程屏障，这需要对它们的长期相互作用进行评估，以确保耐久性。在水热梯度条件下，用钢-钙-镁-钠-膨润土和钠-膨润土不饱和柱分别进行了25个月和27个月的室内实验。实验测量了膨润土孔隙水分布、比表面积、阳离子交换容量和铁氧化态的变化。这些是沿着柱子在不同的部分测定的。矿物学分析采用x射线衍射和扫描电镜进行。所得结果显示了实验结束时的含水饱和度。膨润土在靠近钢界面处的比表面积减小，而阳离子交换容量整体增大。随着时间的推移，腐蚀速率逐渐降低，膨润土在距钢界面3.5 mm范围内铁含量富集。铁-绿泥石、磁铁矿、赤铁矿、磁铁矿和菱铁矿等新的含铁矿物在钢-膨润土界面处被发现为反应产物。由于施加的水力梯度和沉淀反应，水相在膨润土孔隙水中重新分布，随着时间的推移，Na+、Ca2+、Mg2+和SO42−的浓度增加，Fe的浓度降低。本研究比较了这些膨润土性质的演变与先前的研究在短实验时间的1和6个月的反应。这些发现与深部地质处置条件有关，膨润土随着时间的推移影响了铁粘土矿物的形成和性质。

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引用次数: 0

Swelling behaviour of compacted Ca/Mg bentonite during hydration on different scales Ca/Mg膨润土在不同尺度水化过程中的膨胀行为

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-04 DOI: 10.1016/j.clay.2025.108067

Antonia Nitsch , Ali Asaad , Torsten Wichtmann , Katja Emmerich , Wiebke Baille

A mock-up test on decimetric scale in an innovative column test device and small-scale element tests were carried out on a German Ca/Mg bentonite, which is investigated as a suitable material for engineered barrier systems in nuclear waste disposal. Key hydro-mechanical parameters such as relative humidity, water content and swelling pressure were monitored and spatially resolved over the 30 cm height of the column in the mock-up test. The test was hydrated from the bottom and ran for 370 days. To compare the material behaviour at different scales, swelling pressure tests and water retention measurements were performed at the element-test scale. The results of the column test showed a heterogeneous evolution of swelling pressure and hydration state variables along the column height. Simultaneous measurement of vertical and radial swelling pressure indicated swelling anisotropy. Transient measurement of relative humidity and water content revealed a redistribution of porosity within the sample, which was confirmed by sampling after completion of the test. Comparison with the results of the element test showed that the two test scales are comparable in similar hydraulic states. The column test is therefore suitable as a precursor to the field test and provides valuable insights into the spatially and temporally resolved hydration behaviour of a buffer material, which helps for the design of in-situ experiments, the validation of numerical models and supports the overall process understanding.

对德国Ca/Mg膨润土作为核废料处理工程屏障材料的可行性进行了研究，并在新型柱式试验装置上进行了分米尺度的实体试验和小尺度单元试验。在模拟试验中，对相对湿度、含水量和膨胀压力等关键水力学参数进行了监测，并在30cm高度上进行了空间解析。该测试从底部加水，并运行了370天。为了比较材料在不同尺度下的性能，在单元试验尺度下进行了膨胀压力试验和保水性测量。柱试验结果表明，膨胀压力和水化状态变量沿柱高呈非均匀演化。同时测量垂直和径向膨胀压力表明膨胀各向异性。相对湿度和含水量的瞬时测量表明，样品内部孔隙度的重新分布，这在测试完成后通过采样得到了证实。与单元试验结果对比表明，在相似的水力状态下，两种试验尺度具有可比性。因此，柱试验适合作为现场试验的先导，并为缓冲材料的空间和时间分解水化行为提供有价值的见解，这有助于现场实验的设计，数值模型的验证，并支持整体过程的理解。

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引用次数: 0

The electrochemical sensor for sulfamerazine detection in water based on polypyrrole-decorated halloysite nanotubes 基于聚吡咯修饰的高岭土纳米管的水中磺胺嘧啶电化学传感器

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-12-02 DOI: 10.1016/j.clay.2025.108062

Balamurugan Senthil Kumar , Raja Nehru , Cheng-Di Dong

Sulfamerazine (SMR), a widely used sulfonamide antibiotic, has become a significant pollutant in surface water, posing risks to ecosystems and human health. This study presents the development of an innovative electrochemical sensor for detecting SMR in environmental water samples, addressing a critical need for sustainable water monitoring technologies. A composite material based on polypyrrole (PPy) and halloysite nanotubes (HNTs) was synthesized and characterized using comprehensive physicochemical and electrochemical analyses. The polypyrrole decorated halloysite nanotubes (HNT/PPy) composite demonstrated an exceptional electrochemically active surface area, enhanced charge transfer, and superior electrocatalytic performance. The glassy carbon electrode (GCE) modified composite enabled highly sensitive and selective detection of SMR across a broad linear range (0.005–601.985 μM) with a low detection limit (LOD) of 29 nM. The sensor exhibited excellent reproducibility, stability, and anti-interference properties in complex matrices, underscoring its robustness for practical applications. The affordability and scalability of the HNT/PPy composite offer a cost-effective solution for environmental monitoring.

磺胺嘧啶（SMR）是一种广泛使用的磺胺类抗生素，已成为地表水中的重要污染物，对生态系统和人类健康构成威胁。本研究提出了一种用于检测环境水样中SMR的创新电化学传感器的开发，解决了对可持续水监测技术的迫切需求。合成了以聚吡咯（PPy）和高岭土纳米管（HNTs）为基材的复合材料，并用理化和电化学方法对其进行了表征。聚吡咯修饰的高岭土纳米管（HNT/PPy）复合材料具有优异的电化学活性表面积、增强的电荷转移和优异的电催化性能。玻璃碳电极（GCE）修饰的复合材料在宽线性范围（0.005-601.985 μM）内实现了SMR的高灵敏度和选择性检测，检测限（LOD）低至29 nM。该传感器在复杂矩阵中表现出优异的再现性、稳定性和抗干扰性能，强调了其在实际应用中的鲁棒性。HNT/PPy复合材料的可负担性和可扩展性为环境监测提供了经济高效的解决方案。

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引用次数: 0

Measuring piping erosion rate in bentonite using spectrophotometry and X-ray computed tomography 用分光光度法和x射线计算机断层扫描法测量膨润土中管道侵蚀率

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-11-29 DOI: 10.1016/j.clay.2025.108065

Norihisa Osawa , Tomoko Ishii , Kenji Ishii , Yuichi Niibori

For the geological disposal of high-level radioactive waste (HLW), maintaining a buffer density after emplacement in a disposal pit is crucial. Given the abundance of groundwater in Japan, it is necessary to estimate the amount of eroded bentonite from the buffer due to groundwater inflows. Previous quantitative evaluations have been based on the cumulative amount of eroded bentonite, making it difficult to generalize the results.

In this study, bentonite piping erosion was directly measured and quantitatively evaluated using spectrophotometry and X-ray computed tomography (CT). Piping erosion tests were performed by placing the simulated buffer block samples in polycarbonate cells, with deionized water injected from the bottom to the top. After piping developed and stabilized, X-ray CT measurements were conducted to obtain density distribution information and extract piping geometry. Furthermore, the concentration of eroded bentonite in outlet solutions was determined using spectrophotometry. The apparent erosion rate constant (i.e., specific erosion rate) of bentonite was calculated based on X-ray CT measurements and analysis of outlet solutions.

The tests confirmed a strong correlation between water flow rate and actual arc length of piping in the horizontal cross-section, as well as a negative correlation between water flow rate and effluent bentonite concentration. Based on these test results, the apparent erosion rate constants of bentonite remained nearly constant regardless of the water flow rate. Additionally, similar results were obtained when using samples with different montmorillonite content ratios. These findings suggest that the apparent erosion rate constant can be used to estimate the amount of bentonite erosion. Furthermore, this study demonstrates that X-ray CT is a highly effective non-destructive tool for understanding bentonite behavior in buffer materials and providing time-dependent data.

对于高放射性废物（HLW）的地质处置，在放置处置坑后保持缓冲密度是至关重要的。考虑到日本丰富的地下水，有必要估计由于地下水流入而从缓冲区中侵蚀的膨润土的数量。以往的定量评价都是基于侵蚀膨润土的累积量，很难对结果进行概括。在这项研究中，使用分光光度法和x射线计算机断层扫描（CT）直接测量和定量评估了膨润土管道侵蚀。通过将模拟缓冲块样品放置在聚碳酸酯电池中，从底部到顶部注入去离子水，进行管道侵蚀测试。在管道发育并稳定后，进行x射线CT测量以获得密度分布信息并提取管道几何形状。此外，用分光光度法测定了出口溶液中侵蚀膨润土的浓度。基于x射线CT测量和出口溶液分析，计算了膨润土的表观侵蚀速率常数（即比侵蚀速率）。试验结果表明，水流量与管道水平截面实际弧长呈较强的相关关系，出水膨润土浓度与水流量呈负相关关系。试验结果表明，无论水流速率如何，膨润土的表观侵蚀速率常数基本保持不变。此外，不同蒙脱土含量比的样品也得到了相似的结果。这些结果表明，表观侵蚀速率常数可以用来估计膨润土的侵蚀量。此外，该研究表明，x射线CT是一种非常有效的非破坏性工具，可用于了解缓冲材料中膨润土的行为，并提供随时间变化的数据。

{"title":"Measuring piping erosion rate in bentonite using spectrophotometry and X-ray computed tomography","authors":"Norihisa Osawa , Tomoko Ishii , Kenji Ishii , Yuichi Niibori","doi":"10.1016/j.clay.2025.108065","DOIUrl":"10.1016/j.clay.2025.108065","url":null,"abstract":"<div><div>For the geological disposal of high-level radioactive waste (HLW), maintaining a buffer density after emplacement in a disposal pit is crucial. Given the abundance of groundwater in Japan, it is necessary to estimate the amount of eroded bentonite from the buffer due to groundwater inflows. Previous quantitative evaluations have been based on the cumulative amount of eroded bentonite, making it difficult to generalize the results.</div><div>In this study, bentonite piping erosion was directly measured and quantitatively evaluated using spectrophotometry and X-ray computed tomography (CT). Piping erosion tests were performed by placing the simulated buffer block samples in polycarbonate cells, with deionized water injected from the bottom to the top. After piping developed and stabilized, X-ray CT measurements were conducted to obtain density distribution information and extract piping geometry. Furthermore, the concentration of eroded bentonite in outlet solutions was determined using spectrophotometry. The apparent erosion rate constant (i.e., specific erosion rate) of bentonite was calculated based on X-ray CT measurements and analysis of outlet solutions.</div><div>The tests confirmed a strong correlation between water flow rate and actual arc length of piping in the horizontal cross-section, as well as a negative correlation between water flow rate and effluent bentonite concentration. Based on these test results, the apparent erosion rate constants of bentonite remained nearly constant regardless of the water flow rate. Additionally, similar results were obtained when using samples with different montmorillonite content ratios. These findings suggest that the apparent erosion rate constant can be used to estimate the amount of bentonite erosion. Furthermore, this study demonstrates that X-ray CT is a highly effective non-destructive tool for understanding bentonite behavior in buffer materials and providing time-dependent data.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"280 ","pages":"Article 108065"},"PeriodicalIF":5.8,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Control of phosphorus release from sediment by multiple applications of lanthanum-modified palygorskite in the presence of suspended particulate matter input 在存在悬浮颗粒物输入的情况下，镧改性坡缕石的多种应用控制沉积物中磷的释放

IF 5.8 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science

Pub Date : 2025-11-27 DOI: 10.1016/j.clay.2025.108063

Chunyu Tian, Jianwei Lin, Yanhui Zhan

This study explored the performance and underlying mechanisms of multiple applications of lanthanum-modified palygorskite (LMP) for mitigating phosphorus (P) release from sediment to the overlying water under the condition of suspended particulate matter (SPM) input, with a further analysis of the impact of LMP dosing frequency on the control efficiency. The findings revealed that LMP possessed a strong phosphate adsorption capacity in water (maximum adsorption capacity at pH 7: 22.5 mg/g), with significantly higher lanthanum utilization efficiency than pure lanthanum hydroxide (LH) and commercial lanthanum-modified bentonite (LMB). Multiple applications of LMP effectively inhibited the release of sediment-derived P to the overlying water under SPM input conditions, with superior control efficiency compared to multiple applications of LMB. Average reduction efficiencies of SRP in the overlying water of 72.8 %, 76.2 %, and 76.5 % were achieved with six, eleven, and thirty-one applications of LMP, respectively. These multiple LMP applications also effectively suppressed internal P release from the upper sediment layer into the pore water, achieving higher control efficiency than LMB. Even with LMP application, the release of sedimentary P to the pore water continued through mechanisms involving iron-reducing bacteria (IRB)-driven dissimilatory Fe(III) reduction and chemical Fe(III) reduction mediated by sulfate-reducing bacteria (SRB)-driven sulfate reduction products. However, LMP effectively eliminated soluble reactive phosphorus (SRP) in the pore water through two pathways: adsorbing pore water SRP, and inactivating diffusive gradients in thin films (DGT)-labile P and mobile P in the upper sediment. This dual-pathway action constitutes the key mechanism by which multiple LMP applications control the release of sediment-derived P to the overlying water under SPM input conditions. Additionally, the frequency of LMP dosing in the multiple additions affected its efficacy in controlling sediment P release. Overall, multiple applications of LMP represent a highly promising method for controlling sediment P release in the presence of SPM inputs.

本研究探讨了在悬浮颗粒物（SPM）输入条件下，镧改性坡缕石（LMP）多种应用对沉积物上覆水体磷释放的抑制作用及其机制，并进一步分析了LMP投加频率对控制效果的影响。结果表明，LMP在水中具有较强的磷酸盐吸附能力（pH = 7时吸附量最大，为22.5 mg/g），镧的利用率明显高于纯氢氧化镧（LH）和工业镧改性膨润土（LMB）。在SPM输入条件下，多次施用LMP有效地抑制了沉积物源磷向上覆水体的释放，与多次施用LMB相比，控制效率更高。在LMP的6次、11次和31次应用中，SRP在上覆水中的平均还原效率分别达到72.8%、76.2%和76.5%。这些多重LMP应用也有效地抑制了上层沉积物向孔隙水中的内部磷释放，达到了比LMB更高的控制效果。即使使用了LMP，沉积态磷仍通过铁还原细菌（IRB）驱动的异构化Fe（III）还原和硫酸盐还原细菌（SRB）驱动的硫酸盐还原产物介导的化学Fe（III）还原机制继续向孔隙水中释放。然而，LMP通过吸附孔隙水中的可溶性活性磷（SRP）和使上层沉积物中薄膜(DGT)-不稳定P和流动P的扩散梯度失活两种途径有效地消除了孔隙水中的可溶性活性磷（SRP）。这种双途径作用构成了多个LMP应用在SPM输入条件下控制沉积物源磷向上覆水体释放的关键机制。此外，在多次添加中，LMP的添加频率影响其控制沉积物P释放的效果。总的来说，LMP的多种应用代表了在SPM输入存在的情况下控制沉积物P释放的一种非常有前途的方法。

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引用次数: 0