Effects of Hydration of Geosynthetic Clay Liners (GCLs) with Groundwater on their Hydraulic Performance - Abstract
A detailed study was performed to gain knowledge on prehydration of commercially available geosynthetic clay liners (GCLs), and how their hydraulic conductivities are affected by Florida groundwater chemistry. Two groundwater chemistries were used in the study, the chemistry of the groundwater used span the low ionic strength (GW2), and high ionic strength (GW1), of the groundwater data available in literature. Six commercially available GCLs were used in the study. Three of the GCLs were conventional and contained only granular sodium bentonite with different bentonite gradation, while three of the GCLs were polymer-modified and contained granular sodium bentonite that has been dry blended with different quantities of proprietary polymer(s). The polymer modified GCLs contain linear polymer (water-soluble polymer). Our data revealed that fine grained GCL
achieved lower water contents than coarse grained GCL. The polymer modified GCLs showed increase in water uptake over conventional bentonite counterparts (with similar bentonite and geotextiles). The polymer modified GCLs with 3.2 % polymer loading reached higher water content than GCLs with 1.6% polymer loading. Prehydration of the GCLs effectively aided the hydraulic performances when prehydrated with tap water, GW2 and GW1 and permeated with municipal solid waste leachate. When permeated with co-disposal landfill leachates and ash monofil leachates after hydration, the hydraulic conductivity of all GCLs increased.