Guodong Cai , Hailong Wang , Kunlin Ruan , Dachi Ito , Hideo Komine
{"title":"盐溶液渗透后压实膨润土孔隙水中离子浓度的研究","authors":"Guodong Cai , Hailong Wang , Kunlin Ruan , Dachi Ito , Hideo Komine","doi":"10.1016/j.sandf.2024.101467","DOIUrl":null,"url":null,"abstract":"<div><p>The behavior of salt solutions infiltrated into compacted bentonite was investigated in this study, with particular attention paid to the ion concentration in the pore water, in order to improve the understanding of the bentonite behavior in geological disposal projects. A Japanese bentonite, Kunigel V1 (K_V1), was used to prepare specimens with a thickness of 2 mm and an initial dry density of 1.4 to 1.7 Mg/m<sup>3</sup>. For each density case, salt solutions (NaCl, KCl, and CaCl<sub>2</sub>) of different amounts (0 to 2 mol/L) were supplied to the specimens. After infiltration, the basal spacing (<em>d</em><sub>001</sub>) and exchangeable cations of the montmorillonite in the bentonite and the leached cations from the bentonite were measured. Based on the test results, the ion concentration in the interlayer pore water of the montmorillonite or the interparticle pore water was discussed. The findings indicated that the infiltration capacities of the various salt solutions into the compacted K_V1 bentonite were in the order of KCl > CaCl<sub>2</sub> > NaCl. The K_V1 specimen with the highest initial dry density exhibited the strongest resistance to salt solution infiltration. After the infiltration of the NaCl solution into the compacted K_V1 bentonite, the increased sodium ions mainly remained in the interparticle pores, leading to an increase in the sodium ion concentration in the interparticle pore water. During the infiltration of the KCl and CaCl<sub>2</sub> solutions into the compacted K_V1 bentonite, the infiltrated potassium ions in the case of KC1 and the calcium ions in the case of CaCl<sub>2</sub> tended to penetrate the interlayer pore preferentially, thereby displacing the exchangeable sodium ions. After most of the exchangeable sodium ions that had initially existed in the montmorillonite had been replaced, the infiltrated potassium or calcium ions remained in the interparticle pores.</p></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"64 4","pages":"Article 101467"},"PeriodicalIF":3.3000,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0038080624000453/pdfft?md5=2c1b82adc6941e2ba4581fdf00db88df&pid=1-s2.0-S0038080624000453-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Investigation of ion concentration in pore water in compacted bentonite after infiltration by salt solutions\",\"authors\":\"Guodong Cai , Hailong Wang , Kunlin Ruan , Dachi Ito , Hideo Komine\",\"doi\":\"10.1016/j.sandf.2024.101467\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The behavior of salt solutions infiltrated into compacted bentonite was investigated in this study, with particular attention paid to the ion concentration in the pore water, in order to improve the understanding of the bentonite behavior in geological disposal projects. A Japanese bentonite, Kunigel V1 (K_V1), was used to prepare specimens with a thickness of 2 mm and an initial dry density of 1.4 to 1.7 Mg/m<sup>3</sup>. For each density case, salt solutions (NaCl, KCl, and CaCl<sub>2</sub>) of different amounts (0 to 2 mol/L) were supplied to the specimens. After infiltration, the basal spacing (<em>d</em><sub>001</sub>) and exchangeable cations of the montmorillonite in the bentonite and the leached cations from the bentonite were measured. Based on the test results, the ion concentration in the interlayer pore water of the montmorillonite or the interparticle pore water was discussed. The findings indicated that the infiltration capacities of the various salt solutions into the compacted K_V1 bentonite were in the order of KCl > CaCl<sub>2</sub> > NaCl. The K_V1 specimen with the highest initial dry density exhibited the strongest resistance to salt solution infiltration. After the infiltration of the NaCl solution into the compacted K_V1 bentonite, the increased sodium ions mainly remained in the interparticle pores, leading to an increase in the sodium ion concentration in the interparticle pore water. During the infiltration of the KCl and CaCl<sub>2</sub> solutions into the compacted K_V1 bentonite, the infiltrated potassium ions in the case of KC1 and the calcium ions in the case of CaCl<sub>2</sub> tended to penetrate the interlayer pore preferentially, thereby displacing the exchangeable sodium ions. After most of the exchangeable sodium ions that had initially existed in the montmorillonite had been replaced, the infiltrated potassium or calcium ions remained in the interparticle pores.</p></div>\",\"PeriodicalId\":21857,\"journal\":{\"name\":\"Soils and Foundations\",\"volume\":\"64 4\",\"pages\":\"Article 101467\"},\"PeriodicalIF\":3.3000,\"publicationDate\":\"2024-07-06\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S0038080624000453/pdfft?md5=2c1b82adc6941e2ba4581fdf00db88df&pid=1-s2.0-S0038080624000453-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Soils and Foundations\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0038080624000453\",\"RegionNum\":2,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENGINEERING, GEOLOGICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Soils and Foundations","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0038080624000453","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, GEOLOGICAL","Score":null,"Total":0}
Investigation of ion concentration in pore water in compacted bentonite after infiltration by salt solutions
The behavior of salt solutions infiltrated into compacted bentonite was investigated in this study, with particular attention paid to the ion concentration in the pore water, in order to improve the understanding of the bentonite behavior in geological disposal projects. A Japanese bentonite, Kunigel V1 (K_V1), was used to prepare specimens with a thickness of 2 mm and an initial dry density of 1.4 to 1.7 Mg/m3. For each density case, salt solutions (NaCl, KCl, and CaCl2) of different amounts (0 to 2 mol/L) were supplied to the specimens. After infiltration, the basal spacing (d001) and exchangeable cations of the montmorillonite in the bentonite and the leached cations from the bentonite were measured. Based on the test results, the ion concentration in the interlayer pore water of the montmorillonite or the interparticle pore water was discussed. The findings indicated that the infiltration capacities of the various salt solutions into the compacted K_V1 bentonite were in the order of KCl > CaCl2 > NaCl. The K_V1 specimen with the highest initial dry density exhibited the strongest resistance to salt solution infiltration. After the infiltration of the NaCl solution into the compacted K_V1 bentonite, the increased sodium ions mainly remained in the interparticle pores, leading to an increase in the sodium ion concentration in the interparticle pore water. During the infiltration of the KCl and CaCl2 solutions into the compacted K_V1 bentonite, the infiltrated potassium ions in the case of KC1 and the calcium ions in the case of CaCl2 tended to penetrate the interlayer pore preferentially, thereby displacing the exchangeable sodium ions. After most of the exchangeable sodium ions that had initially existed in the montmorillonite had been replaced, the infiltrated potassium or calcium ions remained in the interparticle pores.
期刊介绍:
Soils and Foundations is one of the leading journals in the field of soil mechanics and geotechnical engineering. It is the official journal of the Japanese Geotechnical Society (JGS)., The journal publishes a variety of original research paper, technical reports, technical notes, as well as the state-of-the-art reports upon invitation by the Editor, in the fields of soil and rock mechanics, geotechnical engineering, and environmental geotechnics. Since the publication of Volume 1, No.1 issue in June 1960, Soils and Foundations will celebrate the 60th anniversary in the year of 2020.
Soils and Foundations welcomes theoretical as well as practical work associated with the aforementioned field(s). Case studies that describe the original and interdisciplinary work applicable to geotechnical engineering are particularly encouraged. Discussions to each of the published articles are also welcomed in order to provide an avenue in which opinions of peers may be fed back or exchanged. In providing latest expertise on a specific topic, one issue out of six per year on average was allocated to include selected papers from the International Symposia which were held in Japan as well as overseas.