{"title":"Long-term hydraulic conductivity of bentonite-polymer geosynthetic clay liners","authors":"Hanrui Zhao, Dong Li, Kuo Tian","doi":"10.1016/j.geotexmem.2024.04.006","DOIUrl":null,"url":null,"abstract":"<div><p>Hydraulic conductivity tests were conducted on six bentonite-polymer (B–P) geosynthetic clay liners (GCLs) to investigate the effect of the slow cation exchange process and polymer elution on the long-term hydraulic conductivity of B–P GCLs. Tests were conducted up to 1458 days and as many as 443 pore volumes of flows (PVFs). Three B–P GCLs consist of linear polymer whereas the other three have crosslinked polymer. One sodium geosynthetic clay liner (Na–B GCL) was used as a control. Hydraulic conductivities (K<sub>6766</sub>) of B–P GCLs (5.4 × 10<sup>−12</sup> m/s to 3.7 × 10<sup>−11</sup> m/s) per ASTM D6766 were approximately 2-3 orders of magnitude lower than that of Na–B GCL (2.3 × 10<sup>−9</sup> m/s to 3.5 × 10<sup>−9</sup> m/s). Tests were continued after hydraulic and chemical equilibrium to investigate the long-term hydraulic conductivity of GCLs. Hydraulic conductivities of GCLs had an increasing trend after hydraulic and chemical equilibrium. The ratio of K<sub>L</sub>/K<sub>6766</sub> for B–P GCLs was 3.5–14.7, whereas ratio of K<sub>L</sub>/K<sub>6766</sub> for Na–B GCLs was 1.0–1.7. Total organic carbon (TOC) tests results confirmed that polymer elution occurred during the entire permeation process. The higher ratio of K<sub>L</sub>/K<sub>6766</sub> for B–P GCLs was attributed to the effect of polymer elution.</p></div>","PeriodicalId":55096,"journal":{"name":"Geotextiles and Geomembranes","volume":"52 4","pages":"Pages 800-812"},"PeriodicalIF":4.7000,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geotextiles and Geomembranes","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0266114424000396","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, GEOLOGICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Hydraulic conductivity tests were conducted on six bentonite-polymer (B–P) geosynthetic clay liners (GCLs) to investigate the effect of the slow cation exchange process and polymer elution on the long-term hydraulic conductivity of B–P GCLs. Tests were conducted up to 1458 days and as many as 443 pore volumes of flows (PVFs). Three B–P GCLs consist of linear polymer whereas the other three have crosslinked polymer. One sodium geosynthetic clay liner (Na–B GCL) was used as a control. Hydraulic conductivities (K6766) of B–P GCLs (5.4 × 10−12 m/s to 3.7 × 10−11 m/s) per ASTM D6766 were approximately 2-3 orders of magnitude lower than that of Na–B GCL (2.3 × 10−9 m/s to 3.5 × 10−9 m/s). Tests were continued after hydraulic and chemical equilibrium to investigate the long-term hydraulic conductivity of GCLs. Hydraulic conductivities of GCLs had an increasing trend after hydraulic and chemical equilibrium. The ratio of KL/K6766 for B–P GCLs was 3.5–14.7, whereas ratio of KL/K6766 for Na–B GCLs was 1.0–1.7. Total organic carbon (TOC) tests results confirmed that polymer elution occurred during the entire permeation process. The higher ratio of KL/K6766 for B–P GCLs was attributed to the effect of polymer elution.
期刊介绍:
The range of products and their applications has expanded rapidly over the last decade with geotextiles and geomembranes being specified world wide. This rapid growth is paralleled by a virtual explosion of technology. Current reference books and even manufacturers' sponsored publications tend to date very quickly and the need for a vehicle to bring together and discuss the growing body of technology now available has become evident.
Geotextiles and Geomembranes fills this need and provides a forum for the dissemination of information amongst research workers, designers, users and manufacturers. By providing a growing fund of information the journal increases general awareness, prompts further research and assists in the establishment of international codes and regulations.