Applied Clay Science最新文献

{"title":"Clostridium pasteurianum in kaolin bioleaching: Iron reduction and whitening mechanisms","authors":"Kaiqiang Li ,&nbsp;Jiajiang Lin ,&nbsp;Gary Owens ,&nbsp;Zuliang Chen","doi":"10.1016/j.clay.2025.107998","DOIUrl":"10.1016/j.clay.2025.107998","url":null,"abstract":"<div><div>Previous studies have shown that microbial consortia outperform single strains in bioleaching processes. However, gaps remain in understanding the microbial community structure and functional interactions between key species and critical metabolic genes. This study addressed these questions through iron-reducing microbe-mediated bioleaching experiments combined with multi-omic approaches. The study found four major findings: (1) Bioleaching significantly enhanced the whiteness of kaolin from 60.8 to 90.4 % by selectively removing Fe (III), reducing the Fe (III) content from 1.5 % to 1.2 % without altering the kaolin structure. This process was accompanied by the solubilization of Fe (II). (2) Community succession identified <em>Clostridium</em> (87.7 %), <em>Lysinibacillus</em> (5.9 %), and <em>Bacillus</em> (0.7 %) as the dominant populations. Spearman analysis confirmed strong positive correlations between <em>Clostridium</em> abundance, Fe²⁺ concentration, and whiteness (<em>p</em> &lt; 0.05), suggesting that together with Fe (III) content in kaolin <em>Clostridium</em> plays a key role in whitening. (3) Metagenomic reconstruction revealed <em>Clostridium pasteurianum</em> (50.8 %) was the core functional species. Its complete glycolysis/pyruvate metabolism pathways and acidogenesis gene clusters (lactic/formic/butyric acids) synergistically facilitated Fe (III) dissolution. Notably, this strain exhibited enriched ferredoxin-coding genes and membrane-bound electron transport chain components, suggesting it had a pivotal role in dissimilatory iron reduction. This work provides the first elucidation of structure-function relationships and metabolic networks within iron-reducing consortia, offering both theoretical foundations and practical strategies for sustainable mineral bio-processing.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"278 ","pages":"Article 107998"},"PeriodicalIF":5.8,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119910","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":"Hydrothermal nanoarchitectonics of NiFe layered double hydroxides/FeOOH/graphene oxide composite electrode for enhancement of electrochemical performance","authors":"Jun Chen ,&nbsp;Yuan-yuan Zhang ,&nbsp;Ji-chao Wang ,&nbsp;Wan-qing Zhang ,&nbsp;Yong Zhang","doi":"10.1016/j.clay.2025.107997","DOIUrl":"10.1016/j.clay.2025.107997","url":null,"abstract":"<div><div>In response to the key issues such as poor conductivity, insufficient active sites, and complex preparation processes associated with nickel‑iron layered double hydroxide (NiFe-LDH) and iron oxyhydroxide (FeOOH) electrode materials, this study proposed an innovative solution. A one-step hydrothermal method was employed to directly synthesize the NiFe-LDH/FeOOH composite on a 3D nickel foam substrate, and further prepared the NiFe-LDH/FeOOH/graphene oxide (GO) composite. Through a series of physicochemical characterization techniques, the positive effects of GO doping on the microstructure and electrochemical performance of the composites were systematically investigated. The experimental results showed that under the optimized condition with a GO concentration of 0.208 mg mL⁻¹, the NiFe-LDH/FeOOH/GO composite electrode exhibited excellent electrochemical performance. At current densities of 1, 3, 5, 7, and 10 A g⁻¹, its specific capacitances reached 1813.3, 1580.7, 1416.7, 1288.3, and 1133.8 F g⁻¹ respectively, which were significantly superior to those of the NiFe-LDH/FeOOH composite under the same conditions (1726.7, 1495.3, 1341.1, 1218.8, and 1054.4 F g⁻¹ respectively). In terms of high-current-density performance, at a current density of 10 A g⁻¹, the capacitance retention rate of the NiFe-LDH/FeOOH/GO composite electrode was as high as 62.5 %, significantly better than the 60.1 % of the NiFe-LDH/FeOOH composite. In the cycle stability test, at a current density of 3 A g⁻¹, after 1000 charge-discharge cycles, the capacity retention rate of the NiFe-LDH/FeOOH/GO composite was 69.0 %, far higher than the 22.3 % of the NiFe-LDH/FeOOH material. Even after 5000 cycles, although its capacity retention rate dropped to 25.4 %, it was still higher than the 14.4 % of the NiFe-LDH/FeOOH material. The results of this study provided new ideas for the design of supercapacitor electrode materials with high capacity and high-rate performance and made an important contribution to the development of nanoscale energy materials.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"278 ","pages":"Article 107997"},"PeriodicalIF":5.8,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107680","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 thermal aging at 165 °C–200 °C on bentonite performance","authors":"Sirpa Kumpulainen ,&nbsp;Jari Martikainen ,&nbsp;Teemu Laurila ,&nbsp;Florian Kober ,&nbsp;Olivier Leupin","doi":"10.1016/j.clay.2025.107994","DOIUrl":"10.1016/j.clay.2025.107994","url":null,"abstract":"<div><div>The engineered barrier system in the deep geological repository will encounter varying design loads (hydraulic, mechanical, thermal and chemical) over time. The bentonite buffer may remain dry for long periods of time locally, where access to water from the host rock is low, and consequently, heat may build up increasing the buffer temperature leading to dehydration of smectite. The temperature for complete removal of interlayer water on the smectite is within &gt;150 °C and depends on among others exchangeable cation, smectite type and confining pressure. Although dehydration reactions can be considered reversible, complete dehydration may lead to irreversible alterations. The objective of this work was to determine the effect of thermal aging on bentonite buffer performance.</div><div>Bentonite from Wyoming was thermally aged at 165 °C, 180 °C or 200 °C for 4 weeks, 8 weeks or 20 weeks in a dry, unsaturated state. Thereafter, bentonite was cooled down to room temperature and its properties and performance were evaluated determining the mineralogy by X-ray diffraction (XRD), cation exchange capacity (CEC), swelling index, and performing swelling pressure and hydraulic conductivity tests. Swiss repository conditions were applied for this work using granular bentonite mixture (GBM) and a target dry density of 1450 kg/m³ and Opalinus Clay synthetic porewater (TDS of 16.92 g/l) in swelling pressure and hydraulic conductivity experiments.</div><div>Mineralogical changes observed include dehydration of gypsum and change in clay suspension color indicating small changes in iron oxide mineral phases or contents. No impact on the swelling pressure was noted due to thermal aging, but thermally aged samples had a factor of 1.8 higher hydraulic conductivity compared to references. In addition, up to 4 % decrease in apparent CEC, and up to 25 % decrease in swelling index and faster settling of clay suspensions were observed to occur with thermal aging time and temperature. One potential explanation for observed changes is partial fixation of exchangeable cations and consequent changes in particle size due to heat exposure.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"278 ","pages":"Article 107994"},"PeriodicalIF":5.8,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107679","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":"Carvacrol-loaded montmorillonite–caseinate hybrids as active additives for the development of antimicrobial alginate-chitosan microcapsules","authors":"Mohamed Brahmi ,&nbsp;Sara Moumnassi ,&nbsp;Kamal Essifi ,&nbsp;Emilie Dumas ,&nbsp;Abdeslam Asehraou ,&nbsp;Abdesselam Tahani ,&nbsp;Adem Gharsallaoui","doi":"10.1016/j.clay.2025.107996","DOIUrl":"10.1016/j.clay.2025.107996","url":null,"abstract":"<div><div>This study presented a novel approach for encapsulating carvacrol, a volatile compound with antimicrobial properties, using montmorillonite-based hybrid materials prepared via an evaporation–adsorption process under vacuum at room temperature. These hybrids were incorporated as active additives into alginate-chitosan microcapsules. The effect of montmorillonite surface functionalization was examined by preparing two types of carvacrol-loaded composites: one with sodium caseinate intercalated within the clay layers, and another with caseinate adsorbed onto the external surface. Among these, the intercalated composite (Cas0.5@Mt-3) showed the highest carvacrol adsorption capacity, reaching 176.87 mg/g compared to 155.83 mg/g for the unmodified clay. This enhancement was attributed to the diffusion of carvacrol into the interlayer space, as supported by XRD analysis showing increased interlayer spacing.</div><div>The carvacrol-loaded hybrids were incorporated into alginate matrices at three concentrations (1 %, 2 %, and 3 % <em>w</em>/w) using ionotropic gelation to form stable microcapsules. Higher encapsulation efficiency and loading capacity were achieved with the hybrid composites, likely due to the amphiphilic nature of caseinate, which improved compatibility between the additive and the polymeric matrix, as confirmed by FT-IR and TGA analysis.</div><div>In vitro release studies in food-simulating media revealed more controlled carvacrol release in aqueous medium, while acidic and oily conditions led to faster diffusion. Antimicrobial tests against selected strains demonstrated enhanced inhibition, attributed to the synergistic effect of carvacrol and the polymeric components, particularly chitosan used for crosslinking. These results supported the effectiveness of this approach and its potential for developing active polymer-based systems to improve carvacrol bioavailability in food-related applications.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"278 ","pages":"Article 107996"},"PeriodicalIF":5.8,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107678","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":"Clay mineral formation via interstratified phases in Luvisols formed from amphibolite, northeastern Brazil","authors":"Artur Henrique Nascimento da Silva ,&nbsp;Gabriel Ramatis Pugliese Andrade ,&nbsp;Sheila Aparecida Correia Furquim ,&nbsp;Fábio Soares de Oliveira ,&nbsp;Marilya Gabryella de Sousa ,&nbsp;Marcelo Metri Correa ,&nbsp;Ygor Jacques Agra Bezerra da Silva ,&nbsp;Juliet Emília Santos de Sousa ,&nbsp;Tiago Osório Ferreira ,&nbsp;Xose Lois Otero ,&nbsp;Valdomiro Souza Junior","doi":"10.1016/j.clay.2025.107995","DOIUrl":"10.1016/j.clay.2025.107995","url":null,"abstract":"<div><div>The transformations of clay minerals in Luvisols formed on amphibolite under contrasting semi-arid climates in northeastern Brazil were examined to understand how weathering intensity drives the development of mixed-layer minerals (MLMs) and affects key soil properties. Two Chromic Luvisols, developed from similar amphibolite parent material, each representing distinct climatic conditions (Profile 1: annual precipitation = 415 mm yr⁻¹; Profile 2: = 777 mm yr⁻¹) were sampled across their A, B, and Cr horizons. X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetry and Mössbauer spectroscopy were used to characterize the clay fractions and their interstratified minerals. The results revealed that both soils predominantly feature interstratified kaolinite–smectite (K<img>S) phases, with Profile 1 showing higher proportions of expandable smectite layers. In contrast, Profile 2 exhibited a greater enrichment in kaolinitic layers at all depths. Notably, this study demonstrates that the pedogenetic clay minerals in natural Luvisols from the Brazilian semiarid region consist of transitional MLMs rather than discrete endmembers. It also shows that climatic variation influenced the soil mineralogical composition, primarily through changes in the mixed-layer phases.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"278 ","pages":"Article 107995"},"PeriodicalIF":5.8,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107738","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":"Large-area hybrid silver/nickel-iron layer double hydroxide on metallic tube array for highly sensitive surface-enhanced Raman scattering (SERS) application","authors":"Balasubramanian Sriram ,&nbsp;Alfreda Krisna Altama ,&nbsp;Elaiyappillai Elanthamilan ,&nbsp;Yi-Le Liao ,&nbsp;Sea-Fue Wang ,&nbsp;Jinn P. Chu","doi":"10.1016/j.clay.2025.107986","DOIUrl":"10.1016/j.clay.2025.107986","url":null,"abstract":"<div><div>This paper presented a novel method for the preparation of hybrid metallic tube arrays (MeTA) with Ag coated nickel‑iron layered double hydroxide (LDH) as highly sensitive surface-enhanced Raman scattering (SERS) substrates for the detection of toxic dyes. Nickel‑iron LDH was used as a two-dimensional material with a brucite-like structure featured a large surface area and excellent adsorption capacity. This study leveraged the sharp edges of the array structures in conjunction with the plasmonic properties of silver (a noble metal) to amplify local electromagnetic fields to create plasmonic hot spots. A hybrid heterojunction composed of Ag and LDH on MeTA enhanced the capacity of the substrate to absorb target analytes such as rhodamine 6G (R6G) and malachite green (MG). The substrate demonstrated enhanced SERS performance, as indicated by high enhancement factors in the detection of R6G (2.6 × 10⁸) and MG (1.8 × 10⁶). The arrays exhibited a broad linear dynamic range (R6G: 10⁻⁴ to 10⁻¹⁴ mol L⁻¹; MG: 10⁻⁴ to 10⁻¹⁰ mol L⁻¹), exceeded the ranges reported in previous studies. The structure of the array also revealed good reproducibility and variability. In addition, the limit of detection for R6G was determined to be 6.0 × 10⁻⁹ mol L⁻¹ based on band height calibration and 2.57 × 10⁻⁹ mol L⁻¹ based on band height ratio calibration, respectively. These results underscored the importance of adsorption capacity in developing advanced SERS substrates.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"278 ","pages":"Article 107986"},"PeriodicalIF":5.8,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047824","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":"Author's response to “Discussion on ‘Design of acid-geopolymers based on clays by-products for methylene blue removal from wastewater’ [Applied Clay Science 245 (2023) 107126]” and corrigendum to our recent paper [https://doi.org/10.1016/j.clay.2023.107126]","authors":"Salma En-naji ,&nbsp;Sara Ghazi ,&nbsp;Hanaa Mabroum ,&nbsp;Safaa Mabroum ,&nbsp;Khalid Khatib ,&nbsp;Yassine Taha ,&nbsp;Inés García Lodeiro ,&nbsp;Rachid Hakkou","doi":"10.1016/j.clay.2025.107984","DOIUrl":"10.1016/j.clay.2025.107984","url":null,"abstract":"","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"278 ","pages":"Article 107984"},"PeriodicalIF":5.8,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047825","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 the spiral growth of disordered kaolinite nanocrystals","authors":"Yongjie Yang ,&nbsp;Long Chen ,&nbsp;Jiale Pu ,&nbsp;Qiang Luo ,&nbsp;Maguy Jaber ,&nbsp;Christelle Souprayen ,&nbsp;Ning Wang ,&nbsp;Qinfu Liu","doi":"10.1016/j.clay.2025.107981","DOIUrl":"10.1016/j.clay.2025.107981","url":null,"abstract":"<div><div>Structural disorder in kaolinite critically shapes its reactivity and performance across environmental and industrial contexts. Insights into spiral growth offer a mechanistic framework to decode the structural disorder of kaolinite and advance our understanding of its formation and properties. We identified a distinct expansion of the (001) interlayer spacing, from ∼7.16 Å in well-ordered kaolinite to ∼7.21 Å in disordered samples, along with selective enhancement of the (020) reflection in disordered nanocrystals. This structural disorder is closely linked to Al(4)-for-Si(4) substitution, with a high Al(4)/Al total ratio (∼2.83 %). The ionic radius ratio of <span><math><msub><mi>R</mi><mrow><msup><mi>Al</mi><mi>III</mi></msup><mfenced><mn>4</mn></mfenced></mrow></msub></math></span>_:<span><math><msub><mi>R</mi><msup><mi>O</mi><mrow><mn>2</mn><mo>−</mo></mrow></msup></msub></math></span>=0.438 substantially exceeds that of ideal tetrahedral packing, compared to <span><math><msub><mi>R</mi><mrow><msup><mi>Si</mi><mi>IV</mi></msup><mfenced><mn>4</mn></mfenced></mrow></msub></math></span>_:<span><math><msub><mi>R</mi><msup><mi>O</mi><mrow><mn>2</mn><mo>−</mo></mrow></msup></msub></math></span>=0.331, generating internal stress that exceeds the structural tolerance of triclinic kaolinite. When this stress exceeds a critical threshold, it likely promotes the formation of screw dislocations, which initiate spiral growth and generating stacking faults and in-plane lattice rotations (∼5°), as evidenced by Moiré fringe patterns and SAED. Spiral growth thus acts as a stress-adaptive mechanism, enabling the crystal to accommodate structural instability while maintaining long-range order and anisotropic deformation. These findings recast disorder as a stress-regulated growth strategy and offer a mechanistic blueprint for tuning structure in low-dimensional layered materials.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"277 ","pages":"Article 107981"},"PeriodicalIF":5.8,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145003772","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":"Mechanochemical effect assisted oxidative whitening of black talc","authors":"Huan Shuai ,&nbsp;Xianrong Yang ,&nbsp;Xi Xu ,&nbsp;Gaoxiang Du ,&nbsp;Jiao Wang","doi":"10.1016/j.clay.2025.107961","DOIUrl":"10.1016/j.clay.2025.107961","url":null,"abstract":"<div><div>Black talc, a carbon-intercalated phyllosilicate mineral, is significantly limited in industrial applications due to its intrinsic low whiteness. Conventional whitening methods relying on high-temperature calcination inevitably compromise its layered crystalline structure through thermal decomposition. This study presents a mechanochemically assisted oxidative strategy that achieves effective whitening while preserving structural integrity. By combining mechanical exfoliation with oxidative activation, the interlayer graphite carbon domains in black talc were selectively oxidized, thus significantly increasing the whiteness. Compared with mechanical treatment alone (whiteness 25.7) or chemical treatment alone (whiteness 52.4), the synergistic coupling of mechanical activation and oxidant (whiteness 75.7) increased the whitening efficiency by 626 % and 299 %, respectively. Systematic characterization via X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) revealed a synergistic mechanism: (i) mechanical delamination exposing encapsulated carbon layers and (ii) surface activation promoting oxidative radical generation for carbon removal. Notably, the layered framework remained intact post-treatment, as evidenced by maintained interlayer spacing and absence of phase transformation, contrasting sharply with the structural collapse observed in calcination-based approaches. Although current exploration focuses on carbonaceous minerals, this mechanochemical paradigm establishes a versatile platform for high-value utilization of heat-sensitive mineral resources, particularly in applications demanding structural preservation, such as functional composites and precision ceramics manufacturing.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"277 ","pages":"Article 107961"},"PeriodicalIF":5.8,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144932604","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":"Thiol functionalized kaolin pellets: Development and optimization for mercury ion removal from aqueous solutions","authors":"Awal Adava Abdulsalam ,&nbsp;Madina Pirman ,&nbsp;Dilnaz Begenova ,&nbsp;George Z. Kyzas ,&nbsp;Dehua Xia ,&nbsp;Tri Thanh Pham ,&nbsp;Boris Golman ,&nbsp;Stavros G. Poulopoulos","doi":"10.1016/j.clay.2025.107983","DOIUrl":"10.1016/j.clay.2025.107983","url":null,"abstract":"<div><div>Mercury contamination in aqueous media poses a severe environmental and health risk due to its high toxicity and bioaccumulation potential. In this study, a novel thiol-grafted kaolin pellet adsorbent was developed for efficient Hg²⁺ remediation. The pellet production involved a combination of acid-base treatment, 3-mercaptopropyltrimethoxysilane grafting, and extrusion with polyvinyl alcohol serving as a binder. Additionally, a novel approach was developed to assess biofilm formation on the produced pellets. Characterization results confirmed the successful grafting of thiol groups, providing high-affinity binding sites for Hg²⁺ ions. Optimal operating conditions were identified using 2-mm pellets, 1.5 wt% PVA, 5 g/L dosage, and an initial solution pH of 5, achieving 74.2 % removal and adsorption capacities of up to 12.5 mg/g at 313 K. Kinetic studies revealed that Hg²⁺ uptake followed a pseudo-second-order model (R² = 0.986), while isotherm studies indicated the Freundlich model (R² = 0.987, 0.993, and 0.997 for 293, 303, and 313 K, respectively) as the best model. Antibacterial assays demonstrated that raw and acid-base-treated kaolin pellets inhibited biofilm formation for <em>E. coli (BL21)</em>, <em>P. aeruginosa</em>, <em>S. epidermidis</em>, and <em>S. aureus</em>, whereas thiol-grafted pellets promoted biofilm development, highlighting the need to balance adsorptive enhancement with potential microbial colonization. These findings confirm the potential of kaolin-based pellet adsorbents for Hg²⁺ remediation, offering a viable framework for scaling up into industrial applications.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"277 ","pages":"Article 107983"},"PeriodicalIF":5.8,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144924968","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}