Hydraulic Conductivity of Conventional Sodium Geosynthetic Clay Liners to Synthetic Coal Combustion Product Leachate
6th International Conference on Environmental Geotechnology, Recycled Waste Materials, and Sustainable Engineering, EGRWSE 2025, Vigo, Spain, 11 - 14 June 2025, vol.804 LNCE, pp.447-455, (Full Text)
- Publication Type: Conference Paper / Full Text
- Volume: 804 LNCE
- Doi Number: 10.1007/978-3-032-15832-1_42
- City: Vigo
- Country: Spain
- Page Numbers: pp.447-455
- Keywords: Coal combustion, Geosynthetic clay liner, Hydraulic conductivity, Mass per unit area
- Dokuz Eylül University Affiliated: Yes
Abstract
In this study, the hydraulic conductivity of conventional sodium geosynthetic clay liner (Na-GCL) to coal combustion product leachate (CCP leachate) was investigated. The hydraulic conductivity of Na-GCL was then evaluated in terms of bentonite mass per unit area (μbA) of Na-GCL. The hydraulic conductivity of GCL with 3.0 kg/m2 μbA was high throughout the test and was finally measured as 3.7 × 10–8 m/s. The bundles of fibers on the GCL preferentially conduit the flow across the GCL, resulting in high hydraulic conductivity. The existence of bundles of fibers was approved by performing a dye test on the GCL. When the μbA of GCL increased to 4.0 kg/m2, the hydraulic conductivity of the GCL decreased to 2.4 × 10–11 m/s, which is several orders of magnitude lower than that of GCL with μbA of 3.0 kg/m2. The hydraulic conductivity stayed low when the μbA was further increased to 5.0 kg/m2. This result showed that the critical μbA for the conventional Na-GCL was 4.0 kg/m2, where the hydraulic conductivity was well below the allowable limit suggested for the barriers (i.e., 10–9 m/s).