Daniel D. Jones , Rebecca S. McWatters , R. Kerry Rowe , Indra Kalinovich , Allison Rutter
{"title":"PCB containment using geosynthetics in Canada's Arctic","authors":"Daniel D. Jones , Rebecca S. McWatters , R. Kerry Rowe , Indra Kalinovich , Allison Rutter","doi":"10.1016/j.polar.2023.100928","DOIUrl":null,"url":null,"abstract":"<div><p><span>Two funnel-and-gate permeable reactive barriers<span><span><span> (PRBs) with settling ponds comprised of a composite liner (geomembrane and geosynthetic </span>clay liners<span><span> (GCL)) were installed at Resolution Island (BAF-5), Nunavut to contain residual polychlorinated biphenyls (PCBs) moving with the sediment and annual snowmelt. The long-term performance of the geosynthetics used in the PRB funnels is studied for physical integrity and diffusive barrier properties after nine years of operation. Exhumed geomembrane specimens are compared with virgin material by index testing: diffusive resistance to benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds, as well as puncture, burst, and </span>tensile strength. Exhumed GCLs are evaluated concerning </span></span>hydraulic conductivity<span>, the mass of bentonite per unit area, and swell index. The migration of PCBs through the composite liner system by diffusion is modelled and the diffusive and sorptive properties of the geomembrane (</span></span></span><em>D</em><sub><em>g</em></sub> = 1.7 × 10<sup>−14</sup> m<sup>2</sup>/s, <em>S</em><sub><em>gf</em></sub> = 160,000) and GCL (<em>D</em><sub><em>e</em></sub> = 3.1 × 10<sup>−10</sup> m<sup>2</sup>/s, bentonite plus fibers layer K<sub>d</sub><span> = 15 mL/g, cover geotextile K</span><sub>d</sub> = 12,000 mL/g, and carrier geotextile K<sub>d</sub> = 16,000 mL/g) were calculated. Modelling results estimate that the composite liner was successfully containing PCBs. This was confirmed by downgradient monitoring. The challenges of the location and terrain, PRB design, construction, and maintenance are discussed along with recommendations for designing PRBs in other remote and cold region environments.</p></div>","PeriodicalId":20316,"journal":{"name":"Polar Science","volume":"36 ","pages":"Article 100928"},"PeriodicalIF":1.5000,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Polar Science","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1873965223000051","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ECOLOGY","Score":null,"Total":0}
引用次数: 1
Abstract
Two funnel-and-gate permeable reactive barriers (PRBs) with settling ponds comprised of a composite liner (geomembrane and geosynthetic clay liners (GCL)) were installed at Resolution Island (BAF-5), Nunavut to contain residual polychlorinated biphenyls (PCBs) moving with the sediment and annual snowmelt. The long-term performance of the geosynthetics used in the PRB funnels is studied for physical integrity and diffusive barrier properties after nine years of operation. Exhumed geomembrane specimens are compared with virgin material by index testing: diffusive resistance to benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds, as well as puncture, burst, and tensile strength. Exhumed GCLs are evaluated concerning hydraulic conductivity, the mass of bentonite per unit area, and swell index. The migration of PCBs through the composite liner system by diffusion is modelled and the diffusive and sorptive properties of the geomembrane (Dg = 1.7 × 10−14 m2/s, Sgf = 160,000) and GCL (De = 3.1 × 10−10 m2/s, bentonite plus fibers layer Kd = 15 mL/g, cover geotextile Kd = 12,000 mL/g, and carrier geotextile Kd = 16,000 mL/g) were calculated. Modelling results estimate that the composite liner was successfully containing PCBs. This was confirmed by downgradient monitoring. The challenges of the location and terrain, PRB design, construction, and maintenance are discussed along with recommendations for designing PRBs in other remote and cold region environments.
期刊介绍:
Polar Science is an international, peer-reviewed quarterly journal. It is dedicated to publishing original research articles for sciences relating to the polar regions of the Earth and other planets. Polar Science aims to cover 15 disciplines which are listed below; they cover most aspects of physical sciences, geosciences and life sciences, together with engineering and social sciences. Articles should attract the interest of broad polar science communities, and not be limited to the interests of those who work under specific research subjects. Polar Science also has an Open Archive whereby published articles are made freely available from ScienceDirect after an embargo period of 24 months from the date of publication.
- Space and upper atmosphere physics
- Atmospheric science/climatology
- Glaciology
- Oceanography/sea ice studies
- Geology/petrology
- Solid earth geophysics/seismology
- Marine Earth science
- Geomorphology/Cenozoic-Quaternary geology
- Meteoritics
- Terrestrial biology
- Marine biology
- Animal ecology
- Environment
- Polar Engineering
- Humanities and social sciences.