Suitability of Geosynthetic Clay Liners based on Hydraulic Conductivity for Various Types of Leachate

A tremendous increase in the waste is observed specially in metropolitan cities with the increase in population and industrialization. Corresponding to this increase in the produced waste the number of landfill dumping sites are also on an increasing spree in most of the cities. A solution for the development of these dumping sites is provided by geosynthetic clay liners (GCLs) having low hydraulic conductivity and greater structural stability. GCLs are used as a part of liner system to contain the leachate percolation from solid waste management sites. GCLs are made by encapsulating bentonite between geotextiles (either woven or nonwoven), bonded together by needle-punching. Hydraulic conductivity of GCLs is dependent upon the chemical composition of bentonite as well as the chemical composition of leachate. In this study various commercially available GCLs are tested for their hydraulic conductivity for distilled water as well as for synthetically prepared leachates. A flexi wall permeameter apparatus is used for ascertaining the low hydraulic conductivities of different GCLs available. Economic feasibility of different available GCLs is also compared. Finally, suitability of GCLs based on type of waste for reducing the environmental impact due to landfill dumping sites is suggested.