Applied Clay Science最新文献

{"title":"3D fabric reconstruction and image processing for clays - New method using SEM-FIB technique and AI","authors":"Ismail Myouri ,&nbsp;Fares Bennai ,&nbsp;Julien Guyon ,&nbsp;Mahdia Hattab","doi":"10.1016/j.clay.2025.107943","DOIUrl":"10.1016/j.clay.2025.107943","url":null,"abstract":"<div><div>This paper proposes a new technique for the 3D identification of clay particle orientations using images obtained from FIB-SEM observations. The method is based on a three-dimensional reconstruction that combines the Focused Ion Beam abrasion technique and Scanning Electron Microscopy, applied to kaolinitic clay selected for this study. The clay was first subjected to one-dimensional compression up to a given stress level, after which microstructural observations were performed using a post-mortem approach.</div><div>A novel methodology using appropriate image processing was established for this purpose, allowing for a precise treatment of the obtained FIB-SEM images. The proposed methodology first involved removing “curtain effects” and “charging artefact”, which are specific types of noise commonly associated with FIB-SEM images. Two methods were employed to address this issue and were compared to evaluate their effectiveness: the first method was based on Fourier Transformation and Total Variational Reconstruction, while the second used a stochastic approach formulated as a convex optimization problem. Subsequently, a machine learning technique was integrated to enhance the segmentation process of the images. The final stage of the methodology involved creating a 3D model by reconstructing the clay particles in their spatial configuration. This paper aims to demonstrate how the proposed 3D observation method enables the quantification of the structural organization of clay particles in space in relation to mechanical loading.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"276 ","pages":"Article 107943"},"PeriodicalIF":5.8,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739171","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}

{"title":"High-capacity adsorption and immobilization of Sr in organosilane-modified halloysite","authors":"Li Zhu ,&nbsp;Zheng Zhang ,&nbsp;Xue Xiao ,&nbsp;Daoyong Tan","doi":"10.1016/j.clay.2025.107949","DOIUrl":"10.1016/j.clay.2025.107949","url":null,"abstract":"<div><div>The simulated radionuclide Sr was adsorbed and immobilized by organosilane-modified halloysite. The maximum Sr adsorption amount of organosilane-modified halloysite reached to 585.02 mg/g. Sr was mainly adsorbed into the lumen of organosilane-modified halloysite. The interaction between organosilane-modified halloysite and Sr were both coordination interactions and electrostatic interactions. The Sr adsorption kinetics was well fitted with the pseudo-second-order kinetic model. Sintering at 1100 °C closed the tube end of halloysite nanotube, and sealed the lumen-adsorbed Sr into the internal of the sintered body, leading a steady immobilization of Sr. The simulated leaching experiment demonstrated an excellent stability of Sr. The leaching rate of Sr at 28 d was as low as 1 × 10⁻⁴ g·m⁻²·d⁻¹.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"276 ","pages":"Article 107949"},"PeriodicalIF":5.8,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739170","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}

{"title":"Composite nanocatalysts of amino-organoalkoxysilanes functionalized palygorskite for Knoevenagel condensation reaction","authors":"Shuang Zhou ,&nbsp;Xu Zhang ,&nbsp;Aiying Pang ,&nbsp;Dongqiang Zhang ,&nbsp;Shouyong Zhou ,&nbsp;Zhong Ma ,&nbsp;Jing Shan ,&nbsp;Tingwei Hong ,&nbsp;Wei Fang ,&nbsp;Meisheng Li","doi":"10.1016/j.clay.2025.107941","DOIUrl":"10.1016/j.clay.2025.107941","url":null,"abstract":"<div><div>The development of sustainable heterogeneous basic catalysts is of significant importance in organic synthesis. In this work, three different silane coupling agents—Sil-1, (3-aminopropyl)trimethoxysilane; Sil-2, [3-(2-aminoethylamino)propyl]trimethoxysilane; and Sil-3, (3-[2-(2-aminoethylamino)ethylamino]propyltrimethoxysilane)—were grafted onto palygorskite (Pal) via a silanization strategy to prepare three high-performance, cost-effective, and reusable amino-organoalkoxysilane functionalized Pal composite nanocatalysts, namely Pal-Sil-1, Pal-Sil-2, and Pal-Sil-3. Comprehensive characterization (FT-IR, TGA, XRD, XPS, and SEM) confirmed the intact structure of modified catalysts and the successful introduction of amino active sites. Catalytic experiments show that Pal-Sil-3 exhibited the best catalytic performance among the three different nanocatalysts, achieving a conversion exceeding 98.5 % within 5 min for the Knoevenagel condensation of benzaldehyde and malononitrile in ethanol. It exhibited broad substrate adaptability for various substituted aromatic aldehydes and enabled the efficient synthesis of the drug intermediate isomer (<em>Z</em>)-5-benzylidene-1,3-thiazolidine-2,4-dione. Notably, Pal-Sil-3 maintained stable catalytic efficiency (&gt; 97 % conversion) in a continuous flow system and retained high activity after five reuse cycles. This study provides a novel strategy for developing environmentally friendly heterogeneous catalytic systems and green synthesis of α,β-unsaturated molecules.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"276 ","pages":"Article 107941"},"PeriodicalIF":5.8,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144721742","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}

{"title":"Insight into polycyclic aromatic hydrocarbons removal using novel surfactant-clay hybrid material","authors":"Israel G.A. Funes ,&nbsp;Luciano E. Duarte ,&nbsp;Telma B. Musso ,&nbsp;Luciano Carlos ,&nbsp;María E. Parolo","doi":"10.1016/j.clay.2025.107946","DOIUrl":"10.1016/j.clay.2025.107946","url":null,"abstract":"<div><div>In order to satisfy increasingly strict legal regulations, wastewater treatment technologies require improvements, adaptations, or new developments for the removal of toxic compounds. This work analyses the removal of polyaromatic hydrocarbons (PAHs) from water using two low-cost organoclays as alternative sorbents (H5-Mt/TPODAC-1.5 and Mt./TPODAC-1.5) through static and dynamic experiments. The kinetics features, optimal sorbent dosage, and competitive effects were study by batch adsorption tests using two aqueous solutions spiked with anthracene (ANT) and sixteen PAHs, respectively. Both organoclays showed a high removal capacities for high molecular weight PAHs, which are classified as carcinogenic. The maximum adsorption capacity for ANT was estimated to be 2700 μg g⁻¹ for H5-Mt/TPODAC-1.5 and 3300 μg g⁻¹ for Mt./TPODAC-1.5. The most efficient organoclay was selected for further evaluation in fixed bed columns to assess the influence of operating flow rate, bed length, and initial concentration on the ANT removal. Efficiency parameters such as useful and total bed capacity, mass transfer zone, bed breakpoint time and removal were analysed. Dynamic study using a fixed bed column of 8.5 cm length filled with organoclay conducted over 22 h showed that the remaining concentration of ANT was &lt;4 μg L⁻¹ when the initial ANT concentration in the feed solution was 41 μg L⁻¹.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"276 ","pages":"Article 107946"},"PeriodicalIF":5.8,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144721741","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}

{"title":"Microwave acid treatment induces endogenous active adsorption sites in montmorillonite for cadmium immobilization in soil","authors":"Zhigang Wang,&nbsp;Heng Deng,&nbsp;Yuting Gao,&nbsp;Sen Zhou,&nbsp;Feng Zhou,&nbsp;Guangyu Ye,&nbsp;Chunjie Yan","doi":"10.1016/j.clay.2025.107939","DOIUrl":"10.1016/j.clay.2025.107939","url":null,"abstract":"<div><div>Cadmium (Cd) contamination poses significant environmental and health risks, particularly in soil and water systems. In response to this, this work presents a novel approach for enhancing the cadmium adsorption capacity of montmorillonite (Mt) through microwave-assisted acid treatment (MAT). This treatment selectively generates highly reactive Al(<em>V</em>) sites, leading to a dramatic increase in specific surface area (from 69.4 to 388.32 m²/g), porosity, and the availability of active adsorption sites. As a result, at low cadmium concentrations, 4MAT-Mt exhibits significantly improved Cd removal performance (∼99.9 % removal efficiency) compared to pristine Mt. (∼95 % removal efficiency). The adsorption process follows pseudo-second-order kinetics, indicating that chemical interactions are the primary driving force. Additionally, 4MAT-Mt demonstrates exceptional efficiency in soil remediation, effectively reducing Cd leachability (nearly 100 %) at low Cd concentrations. These findings suggest that 4MAT-Mt, with its enhanced adsorption properties, offers a promising, sustainable solution for mitigating Cd pollution in contaminated environments.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"276 ","pages":"Article 107939"},"PeriodicalIF":5.3,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714274","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}

{"title":"U(VI) adsorption on mudstone in the presence of carbonate: Batch experiments, modeling, cryo-TRLFS and PARAFAC analysis","authors":"Huiyang Mei ,&nbsp;Noboru Aoyagi ,&nbsp;Takumi Saito ,&nbsp;Kazuya Tanaka ,&nbsp;Yuki Sugiura ,&nbsp;Yukio Tachi","doi":"10.1016/j.clay.2025.107944","DOIUrl":"10.1016/j.clay.2025.107944","url":null,"abstract":"<div><div>Dissolved inorganic carbon (DIC) present in groundwaters near geological disposal site may affect the migration and fate of released radionuclides (e.g., uranium). However, it is still unclear how DIC affects the sorption of U(VI) on mudstone, a potential choice for host rock formation barriers, and the characteristics of U(VI) adsorption species. In view of this, adsorption of U(VI) on mudstone as a function of pH or the DIC level was investigated through batch adsorption experiments, component additivity (CA) modeling, and parallel factor (PARAFAC) analysis of cryogenic time-resolved laser fluorescence spectroscopy (cryo-TRLFS). The inhibition effect of DIC on adsorption of U(VI) was deduced from the batch experimental results. The CA model considering montmorillonite and illite as the main phases responsible for adsorption reflected the variation trend but underestimated the experimental data. Three components were decomposed from the PARAFAC analysis of the cryo-TRLFS data of mudstone and adsorption samples. Based on the spectral shapes, lifetimes, and variation trends, two components were assigned to the naturally occurring U(VI) species in the mudstone matrix and the third component to a ternary uranyl‑carbonate surface species. The obtained results imply a significant influence of the DIC level on retention and fate of U(VI), which needs to be considered in safety assessment of potential deep geological disposal schemes.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"276 ","pages":"Article 107944"},"PeriodicalIF":5.3,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714196","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}

{"title":"Investigation of iron oxide and kaolinite interactions during sintering under controlled atmosphere","authors":"Fleur Guillemin ,&nbsp;Mathieu Duttine ,&nbsp;Gisèle Lecomte-Nana ,&nbsp;Youssef El Hafiane ,&nbsp;Claire Peyratout ,&nbsp;Agnès Smith","doi":"10.1016/j.clay.2025.107945","DOIUrl":"10.1016/j.clay.2025.107945","url":null,"abstract":"<div><div>This study investigates the impact of atmosphere conditions on the thermal transformations of iron-enriched kaolin. Natural kaolin was chemically enriched with iron at two concentrations. Fine characterisation was conducted using X-ray diffraction, Mössbauer spectroscopy, solid-state nuclear magnetic resonance and electron dispersive spectroscopy. The samples were heat-treated at 1050 °C and 1400 °C under synthetic air and argon to assess the influence of these conditions on their transformations.</div><div>Analyses revealed that presence of iron significantly influenced reaction kinetics. Under oxidizing atmosphere, the formation of mullite was facilitated by an equilibrium with hematite. The presence of iron accelerated the formation of secondary mullite and cristobalite, though the effect was not proportional to iron concentration. Conversely, under oxygen-deficient atmosphere, the reaction pathway diverged, leading to the formation of hercynite, tridymite (and after cristobalite) and mullite. Iron similarly promoted formation of these phases. No significant differences were observed for the pure kaolin sample under either atmosphere.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"276 ","pages":"Article 107945"},"PeriodicalIF":5.3,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714197","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}

{"title":"The hidden message of fine-grained sediments: towards a new depositional model for the Opalinus Clay","authors":"Géraldine Nicole Zimmerli ,&nbsp;Stephan Wohlwend ,&nbsp;Gaudenz Deplazes ,&nbsp;Thomas Mann ,&nbsp;Jochen Erbacher ,&nbsp;Tilo Kneuker ,&nbsp;Gregor Paul Eberli ,&nbsp;Anneleen Foubert","doi":"10.1016/j.clay.2025.107934","DOIUrl":"10.1016/j.clay.2025.107934","url":null,"abstract":"<div><div>Fine-grained sediments, including clay mineral-rich sediments, are essential for radioactive waste storage due to their sealing properties and low permeability. The Opalinus Clay in Switzerland and Opalinuston-Formation in Germany, summarized as Opalinus Clay, plays a key role in this context. Despite its apparent homogeneity, its depositional history remains complex. This study examined 20 drill cores using sedimentary petrography, grain size analyses, and revised thickness data from 477 drill cores across Switzerland, Germany, and France. Three lithological facies associations (FA) were identified: FA-1 (clay mineral-rich dominated), FA-2 (silt dominated), and FA-3 (silt/clay mineral-rich dominated with mainly calcareous beds). The Opalinus Clay shows overall poor to very poor sorting but with a dominant well-sorted silt fraction. Paleo-current velocity calculations based on the sortable silt fraction indicate lower values in more clayey subfacies (25 cm/s) and higher values in silty subfacies (27 – 32 cm/s). Multiple coarsening- and fining-upward trends are identified indicating a fluctuating current environment. The Opalinus Clay reveals thickness variations with the thickest deposits located in the central part of the Opalinus Clay Basin and thinner deposits towards the margins. The combination of sedimentary facies, grain size analyses and thickness variations suggest that the succession represents a shallow-water contourite drift formed by dominant north-to-south flowing currents. Hydrodynamic conditions changed through time and space, with strengthening of the current system towards the top of the succession and stronger currents in the south (Switzerland) compared to the north (Germany). Continuous current dynamics resulted in predictable trends in facies evolution with relatively few small-scaled facies variations. This uniformity is essential for the effectiveness as a geological barrier and its suitability for radioactive waste disposal.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"276 ","pages":"Article 107934"},"PeriodicalIF":5.3,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711758","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}

{"title":"Study on the preparation of mineral silicon-potassium fertilizer by hydrothermal leaching of kaolinite to generate potassium aluminosilicate under the “calcification-potash alkali” system","authors":"Qingdong Li ,&nbsp;Guozhi Lv ,&nbsp;Shuojia Song ,&nbsp;Renyun Zhang ,&nbsp;Xin He ,&nbsp;Fangyi Yuan ,&nbsp;Zhuangzhuang Yun ,&nbsp;Tingan Zhang","doi":"10.1016/j.clay.2025.107935","DOIUrl":"10.1016/j.clay.2025.107935","url":null,"abstract":"<div><div>Kaolinite is a typical silicate mineral found in bauxite, which tends to combine with sodium aluminosilicate hydrate (red mud) as the equilibrium solid phase in the Bayer process. This combination leads to increased losses of alumina and alkali, resulting in environmental pollution. Kaolinite and other aluminum and silica mineral phases are considered harmful impurities in alumina production. Their removal complicates the treatment process, increases production costs, and does not fundamentally address the issue of red mud accumulation and emissions. This study proposes a “calcification-potash alkali”(CPA) process, wherein potash is utilized instead of sodium alkali to simulate the hydrothermal leaching of kaolinite, the primary silicon-containing mineral phase in bauxite, during the Bayer process. The transformation product is Kaliophilite(KAlSiO₄), which can be used to prepare mineral-based silicon‑potassium fertilizers. This paper investigates the dissolution behavior and mechanism of kaolinite during the leaching process. Leaching experiments and analyses (FTIR, XRD, XRF, XPS, and SEM-EDS) reveal that potassium oxide concentration and alkali leaching temperature are the main factors influencing kaolinite transformation. The optimal dissolution conditions are a temperature of 200 °C, a calcium-to‑silicon ratio of 0.2, a K₂O concentration of 160 g/L, and a reaction time of 60 min. Under these conditions, the kaolinite reaction rate reaches 98.9 %, yielding potassium aluminosilicate. Furthermore, the heavy metal content and other indices met relevant standards, allowing for its incorporation into organic matter and the preparation of mineral silica‑potassium fertilizers to partially replace industrial fertilizers in agriculture, offering significant cost advantages and promising market prospects. This process transforms the silicon-containing mineral phase in bauxite from waste into a valuable resource, offering a new reference for the utilization of medium- and low-grade bauxite as well as the treatment of red mud.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"276 ","pages":"Article 107935"},"PeriodicalIF":5.3,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703419","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}

{"title":"Effect of water saturation on the diffusive transport of water and solutes in compacted kaolinite, illite and vermiculite","authors":"Lucas Désert ,&nbsp;Sébastien Savoye ,&nbsp;Eric Ferrage ,&nbsp;Fabien Hubert ,&nbsp;Pierre Henocq ,&nbsp;Christophe Tournassat ,&nbsp;Emmanuel Tertre","doi":"10.1016/j.clay.2025.107928","DOIUrl":"10.1016/j.clay.2025.107928","url":null,"abstract":"<div><div>Through-diffusion experiments were carried out under partially water saturated conditions and using uncharged tracers (HTO and HDO; water molecule with one tritium and deuterium atom, respectively), negatively charged tracers (¹²⁵I⁻ and ³⁶Cl⁻) and positively charged tracer (²²Na⁺) in two reference clayey materials: (i) illite, a negatively-charged clay mineral with only interparticle porosity and (ii) vermiculite, a negatively-charged clay mineral with both inter-particle and interlayer porosities. For both types of porous media, a sharp decrease in diffusive flux was observed for all three types of tracer when water saturation (S_w) was reduced from S_w = 0.95 to 0.88. The data were compared to those obtained previously with porous media made of kaolinite, a weakly-charged clay mineral having only inter-particle porosity, to quantify the relative influences of surface charge and pore geometry/pore size distribution on diffusion properties as a function of water saturation. The latter parameter had a prominent role on the diffusional properties in the investigated range of S_w, regardless of the type of clayey material. Then, a relationship predicting diffusivities of cation under partially water saturated conditions as a function of diffusivities of anion at the same level of water saturation is proposed for the reference clayey materials investigated.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"276 ","pages":"Article 107928"},"PeriodicalIF":5.3,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679243","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}