Maoling Wu , Keding Li , Bowen Zheng , Li Yang , Lin Zhang , Xuan Luo
{"title":"热解温度对高岭土结构和铀分离特性的影响","authors":"Maoling Wu , Keding Li , Bowen Zheng , Li Yang , Lin Zhang , Xuan Luo","doi":"10.1016/j.surfin.2025.106177","DOIUrl":null,"url":null,"abstract":"<div><div>Kaolin (KL) is regarded as an available adsorbent for U-containing wastewater treatment owing to its rich resources, low price, high chemical stability and excellent ion-exchange ability. While, the U removal performances of KL are constrained by its structure and poor active sites. Thermal activation is an efficient way to improve the U removal capacity of KL through expanding contact aera and providing more available adsorption sites. While, there were few researches about elaborating the relationship between KL structural properties, adsorption performances and pyrolysis temperature. In this study, the structure of KL at different pyrolysis temperatures relationship with its U separation characteristics was investigated at first. According to the results of characterizations, pyrolysis temperature obviously affected the crystal structure, phase composition and microstructure of KL. By comparison, KL pyrolyzed at 500 °C (KL-500) possessed rougher surface and stripped layer structure, thus providing more adsorptive sites to combine with uranyl. The experimental results indicate that KL-500 showed higher U separation rate (90.4 %) and larger U adsorption capacity (530.8 mg/g). Meanwhile, the maximum U removal capacity of KL-500 was larger than most of reported clay-based materials, illustrating the potential of practical application. Besides, KL-500 also performed favorable recoverability with the U adsorption rate of 80.2 % at the fifth cycle, meaning that KL was expected for treating natural wastewater. The fitting results of isotherm and kinetics models verified that the removal process of U on KL-500 was mainly single layer chemical adsorption. The surface charge of KL was negative due to deprotonation at pH 5.0, thus causing strong electrostatic attraction between adsorbents and uranyl. Combining the results of XPS spectra, the immobilization of U on KL-500 was mainly realized through electrostatic interaction and complexation, which was a combination process of physical and chemical adsorption, with chemical adsorption dominating.</div></div>","PeriodicalId":22081,"journal":{"name":"Surfaces and Interfaces","volume":"62 ","pages":"Article 106177"},"PeriodicalIF":5.7000,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The effect of pyrolysis temperature on the structure and uranium separation characteristics of kaolin\",\"authors\":\"Maoling Wu , Keding Li , Bowen Zheng , Li Yang , Lin Zhang , Xuan Luo\",\"doi\":\"10.1016/j.surfin.2025.106177\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Kaolin (KL) is regarded as an available adsorbent for U-containing wastewater treatment owing to its rich resources, low price, high chemical stability and excellent ion-exchange ability. While, the U removal performances of KL are constrained by its structure and poor active sites. Thermal activation is an efficient way to improve the U removal capacity of KL through expanding contact aera and providing more available adsorption sites. While, there were few researches about elaborating the relationship between KL structural properties, adsorption performances and pyrolysis temperature. In this study, the structure of KL at different pyrolysis temperatures relationship with its U separation characteristics was investigated at first. According to the results of characterizations, pyrolysis temperature obviously affected the crystal structure, phase composition and microstructure of KL. By comparison, KL pyrolyzed at 500 °C (KL-500) possessed rougher surface and stripped layer structure, thus providing more adsorptive sites to combine with uranyl. The experimental results indicate that KL-500 showed higher U separation rate (90.4 %) and larger U adsorption capacity (530.8 mg/g). Meanwhile, the maximum U removal capacity of KL-500 was larger than most of reported clay-based materials, illustrating the potential of practical application. Besides, KL-500 also performed favorable recoverability with the U adsorption rate of 80.2 % at the fifth cycle, meaning that KL was expected for treating natural wastewater. The fitting results of isotherm and kinetics models verified that the removal process of U on KL-500 was mainly single layer chemical adsorption. The surface charge of KL was negative due to deprotonation at pH 5.0, thus causing strong electrostatic attraction between adsorbents and uranyl. Combining the results of XPS spectra, the immobilization of U on KL-500 was mainly realized through electrostatic interaction and complexation, which was a combination process of physical and chemical adsorption, with chemical adsorption dominating.</div></div>\",\"PeriodicalId\":22081,\"journal\":{\"name\":\"Surfaces and Interfaces\",\"volume\":\"62 \",\"pages\":\"Article 106177\"},\"PeriodicalIF\":5.7000,\"publicationDate\":\"2025-03-07\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Surfaces and Interfaces\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2468023025004365\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Surfaces and Interfaces","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2468023025004365","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
The effect of pyrolysis temperature on the structure and uranium separation characteristics of kaolin
Kaolin (KL) is regarded as an available adsorbent for U-containing wastewater treatment owing to its rich resources, low price, high chemical stability and excellent ion-exchange ability. While, the U removal performances of KL are constrained by its structure and poor active sites. Thermal activation is an efficient way to improve the U removal capacity of KL through expanding contact aera and providing more available adsorption sites. While, there were few researches about elaborating the relationship between KL structural properties, adsorption performances and pyrolysis temperature. In this study, the structure of KL at different pyrolysis temperatures relationship with its U separation characteristics was investigated at first. According to the results of characterizations, pyrolysis temperature obviously affected the crystal structure, phase composition and microstructure of KL. By comparison, KL pyrolyzed at 500 °C (KL-500) possessed rougher surface and stripped layer structure, thus providing more adsorptive sites to combine with uranyl. The experimental results indicate that KL-500 showed higher U separation rate (90.4 %) and larger U adsorption capacity (530.8 mg/g). Meanwhile, the maximum U removal capacity of KL-500 was larger than most of reported clay-based materials, illustrating the potential of practical application. Besides, KL-500 also performed favorable recoverability with the U adsorption rate of 80.2 % at the fifth cycle, meaning that KL was expected for treating natural wastewater. The fitting results of isotherm and kinetics models verified that the removal process of U on KL-500 was mainly single layer chemical adsorption. The surface charge of KL was negative due to deprotonation at pH 5.0, thus causing strong electrostatic attraction between adsorbents and uranyl. Combining the results of XPS spectra, the immobilization of U on KL-500 was mainly realized through electrostatic interaction and complexation, which was a combination process of physical and chemical adsorption, with chemical adsorption dominating.
期刊介绍:
The aim of the journal is to provide a respectful outlet for ''sound science'' papers in all research areas on surfaces and interfaces. We define sound science papers as papers that describe new and well-executed research, but that do not necessarily provide brand new insights or are merely a description of research results.
Surfaces and Interfaces publishes research papers in all fields of surface science which may not always find the right home on first submission to our Elsevier sister journals (Applied Surface, Surface and Coatings Technology, Thin Solid Films)