Adsorption and hydraulic conductivity of landfill-leachate perfluorinated compounds in bentonite barrier mixtures

Perfluorinated compounds (PFCs) are leached in landfills from a wide range of domestic and industrial products. Sodium bentonite, a common barrier material, was contacted with water and landfill leachate spiked with PFCs in batch adsorption tests to measure PFC adsorption. Leaching cell tests were also conducted in which water, landfill leachate and PFC-spiked leachate permeated through compacted sand-bentonite mixtures. It was found that the PFCs did not bind substantially to the bentonite. Hydraulic conductivities were not appreciably affected by the PFCs, showing that bentonite liners are not affected for the range of concentrations tested. The sand-bentonite mixture partially retained the PFCs, indicating limited effectiveness in containing PFC within landfills.