Liner Systems for Municipal Solid Landfill Waste under Elevated Temperatures

Analysis of Hydraulic Conductivity of GCLs Under Influence of Elevated Temperature

Today in the US, there are about 13,000 municipal solid waste landfills (MSWLF) that receive tons of waste every day. These landfills are designed with a cover system to prevent leakage of rainwater from the top of the landfill and a liner system to prevent leachate waste from permeating through liners into groundwater. In the past landfill, the design required a composite liner consisting of geomembrane overlying a 0.6-m thick compacted clay liner (CCL). However, geosynthetic clay liners (GCL’s) are in lieu of CCL due to easy installation, thin material to save air space, and its low hydraulic conductivity (< 10-10 m/s). GCL typically consists of a layer of sodium bentonite sandwiched between two geotextiles. GCL can be modified through the addition of polymerized bentonite to increase its chemical compatibility against aggressive landfill leachates. Landfills typically have elevated temperatures due to the biodegradation of organics in the waste. The temperature in an MSWLF increase as a function of depth with a gradient of 0.5 o C/m to 3o C/m

My research will focus on the effect of elevated temperatures (e.g., 20, 35, 60 o C) on the performance of hydraulic conductivity of sodium bentonite and polymer modified GCL’s. The hydraulic conductivity test of GCL with saline solutions will be conducted in accordance with ASTM D6766. The saline solution will be used to mimic dilute to aggressive leachates in a landfill.