Chao Hu , Feiyu Teng , Xinjia Yin , Pu Wang , Bianyang He , Lei Zhu
{"title":"半胱氨酸修饰柱状蒙脱土对重金属的吸附:机理与特性","authors":"Chao Hu , Feiyu Teng , Xinjia Yin , Pu Wang , Bianyang He , Lei Zhu","doi":"10.1016/j.clay.2025.107923","DOIUrl":null,"url":null,"abstract":"<div><div>Montmorillonite enhanced its adsorption performance through the modification with organic and inorganic materials. Among various modifiers, cysteine was known for its significant ability to bind heavy metals due to the presence of thiol and amino functional groups. This study used X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and a series of adsorption experiments to examine the interaction between FeCl<sub>3</sub>-AlCl<sub>3</sub> pillared montmorillonite (P<img>Mt) and cysteine (Cys), and to investigate the adsorption characteristics and mechanisms of the composite of pillared montmorillonite and cysteine (P-Mt-Cys) toward heavy metals. The XRD and FTIR results indicated that cysteine intercalated into the layers of the pillared montmorillonite and, through its functional groups, dominated the surface of the P-Mt-Cys composite. The pillaring material slowed down the rate at which cysteine entered the montmorillonite and established pH 5.0 as the optimal electrochemical condition for cysteine intercalation. The adsorption of cysteine onto P<img>Mt followed a pseudo-second-order kinetic model, and the Dubinin-Radushkevich (D-R) isothermal adsorption model provided a good fit for the data. In the pH range of 5.0–5.5, P-Mt-Cys exhibited superior adsorption of Cu(II) compared to unmodified Mt. and P<img>Mt. The adsorption of Cu(II) on P-Mt-Cys reached equilibrium within 120 min. The Freundlich isothermal adsorption model best described the multilayer adsorption of Cu(II), with a maximum adsorption capacity of 27.02 mg g<sup>−1</sup> at an equilibrium concentration of 81.91 mg L<sup>−1</sup>. The adsorption process was exothermic and spontaneous, and the adsorption amount decreased as the temperature increased. Additionally, both the enthalpy change and entropy change were negative. These findings established the foundation for understanding the adsorption characteristics of heavy metals and offered a reference for further studies on the Mt-Cys-heavy metal system.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"276 ","pages":"Article 107923"},"PeriodicalIF":5.3000,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Adsorption of heavy metals using cysteine-modified pillared montmorillonite: Mechanisms and characteristics\",\"authors\":\"Chao Hu , Feiyu Teng , Xinjia Yin , Pu Wang , Bianyang He , Lei Zhu\",\"doi\":\"10.1016/j.clay.2025.107923\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Montmorillonite enhanced its adsorption performance through the modification with organic and inorganic materials. Among various modifiers, cysteine was known for its significant ability to bind heavy metals due to the presence of thiol and amino functional groups. This study used X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and a series of adsorption experiments to examine the interaction between FeCl<sub>3</sub>-AlCl<sub>3</sub> pillared montmorillonite (P<img>Mt) and cysteine (Cys), and to investigate the adsorption characteristics and mechanisms of the composite of pillared montmorillonite and cysteine (P-Mt-Cys) toward heavy metals. The XRD and FTIR results indicated that cysteine intercalated into the layers of the pillared montmorillonite and, through its functional groups, dominated the surface of the P-Mt-Cys composite. The pillaring material slowed down the rate at which cysteine entered the montmorillonite and established pH 5.0 as the optimal electrochemical condition for cysteine intercalation. The adsorption of cysteine onto P<img>Mt followed a pseudo-second-order kinetic model, and the Dubinin-Radushkevich (D-R) isothermal adsorption model provided a good fit for the data. In the pH range of 5.0–5.5, P-Mt-Cys exhibited superior adsorption of Cu(II) compared to unmodified Mt. and P<img>Mt. The adsorption of Cu(II) on P-Mt-Cys reached equilibrium within 120 min. The Freundlich isothermal adsorption model best described the multilayer adsorption of Cu(II), with a maximum adsorption capacity of 27.02 mg g<sup>−1</sup> at an equilibrium concentration of 81.91 mg L<sup>−1</sup>. The adsorption process was exothermic and spontaneous, and the adsorption amount decreased as the temperature increased. Additionally, both the enthalpy change and entropy change were negative. These findings established the foundation for understanding the adsorption characteristics of heavy metals and offered a reference for further studies on the Mt-Cys-heavy metal system.</div></div>\",\"PeriodicalId\":245,\"journal\":{\"name\":\"Applied Clay Science\",\"volume\":\"276 \",\"pages\":\"Article 107923\"},\"PeriodicalIF\":5.3000,\"publicationDate\":\"2025-07-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Applied Clay Science\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0169131725002285\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Clay Science","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0169131725002285","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Adsorption of heavy metals using cysteine-modified pillared montmorillonite: Mechanisms and characteristics
Montmorillonite enhanced its adsorption performance through the modification with organic and inorganic materials. Among various modifiers, cysteine was known for its significant ability to bind heavy metals due to the presence of thiol and amino functional groups. This study used X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and a series of adsorption experiments to examine the interaction between FeCl3-AlCl3 pillared montmorillonite (PMt) and cysteine (Cys), and to investigate the adsorption characteristics and mechanisms of the composite of pillared montmorillonite and cysteine (P-Mt-Cys) toward heavy metals. The XRD and FTIR results indicated that cysteine intercalated into the layers of the pillared montmorillonite and, through its functional groups, dominated the surface of the P-Mt-Cys composite. The pillaring material slowed down the rate at which cysteine entered the montmorillonite and established pH 5.0 as the optimal electrochemical condition for cysteine intercalation. The adsorption of cysteine onto PMt followed a pseudo-second-order kinetic model, and the Dubinin-Radushkevich (D-R) isothermal adsorption model provided a good fit for the data. In the pH range of 5.0–5.5, P-Mt-Cys exhibited superior adsorption of Cu(II) compared to unmodified Mt. and PMt. The adsorption of Cu(II) on P-Mt-Cys reached equilibrium within 120 min. The Freundlich isothermal adsorption model best described the multilayer adsorption of Cu(II), with a maximum adsorption capacity of 27.02 mg g−1 at an equilibrium concentration of 81.91 mg L−1. The adsorption process was exothermic and spontaneous, and the adsorption amount decreased as the temperature increased. Additionally, both the enthalpy change and entropy change were negative. These findings established the foundation for understanding the adsorption characteristics of heavy metals and offered a reference for further studies on the Mt-Cys-heavy metal system.
期刊介绍:
Applied Clay Science aims to be an international journal attracting high quality scientific papers on clays and clay minerals, including research papers, reviews, and technical notes. The journal covers typical subjects of Fundamental and Applied Clay Science such as:
• Synthesis and purification
• Structural, crystallographic and mineralogical properties of clays and clay minerals
• Thermal properties of clays and clay minerals
• Physico-chemical properties including i) surface and interface properties; ii) thermodynamic properties; iii) mechanical properties
• Interaction with water, with polar and apolar molecules
• Colloidal properties and rheology
• Adsorption, Intercalation, Ionic exchange
• Genesis and deposits of clay minerals
• Geology and geochemistry of clays
• Modification of clays and clay minerals properties by thermal and physical treatments
• Modification by chemical treatments with organic and inorganic molecules(organoclays, pillared clays)
• Modification by biological microorganisms. etc...