Performance of Geosynthetic Clay Liner with Polymerized Bentonite in Highly Acidic or Alkaline Solutions

Prongmanee, Nutthachai; Chai, Jinchun

doi:10.1007/s40891-019-0177-7

Cited by 16 publications

(1 citation statement)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Chemical incompatibility issues associated with the use of NaB have motivated research and development of enhanced bentonites (EBs) utilizing polymer and organic amendments to improve chemical resistance to aggressive solutions. Previous studies have demonstrated the ability of bentonite-polyacrylic-acid composite (BPC) and other EBs amended with similar polyacrylategroup hydrogels to maintain low k (<10 À10 m/s) when permeated with real or artificial landfill leachates (e.g., , coal combustion product (CCP) leachates (e.g., Chen et al 2019), seawater (e.g., De Camillis et al 2016), radioactive waste leachates (e.g., Tian et al 2016a), and other aggressive chemical solutions (e.g., Scalia and Benson 2017;Prongmanee and Chai 2019).…”

Section: Introductionmentioning

confidence: 99%

Diffusion through sodium and polymer enhanced bentonites exposed to dilute and aggressive solutions

2021

View full text Add to dashboard Cite

Chemical incompatibility between sodium bentonite (NaB) and aggressive waste solutions has led to the development of enhanced bentonites for geoenvironmental applications. Enhanced bentonites, such as bentonite-polyacrylic-acid composite (BPC), have been shown to maintain low enough values of hydraulic conductivity (e.g. < 10-10 m/s) for diffusion to be the dominant transport mechanism, even upon exposure to aggressive solutions. However, quantification of diffusion properties of enhanced bentonites has been limited. In this study, apparent diffusion coefficients (Da) for chloride were measured for NaB and polymer enhanced NaBs. Diffusion tests were performed using dilute (5 mM) to aggressive (100 mM) calcium chloride (CaCl2) solutions. In addition, scanning electron microscopy was performed to support interpretation of diffusion results. For CaCl2 solutions < 100 mM, Da values for BPC were lower (by approximately half an order of magnitude) than Da values for NaB. However, differences in Da due to polymer enhancement diminished as CaCl2 concentration increased. Predicted steady-state flux through a BPC geosynthetic clay liner (GCL) was dominated by diffusion and up to two orders of magnitude lower than flux through an NaB GCL. These results provide insight regarding diffusion in polymer enhanced bentonites and expected performance of containment barriers with enhanced-bentonite GCLs.

show abstract