Permeability Studies on Different Prefabricated Landfill Liners Developed Using Coir Geotextile and Polypropylene Felt

摘要

Geosynthetic clay liners (GCLs) have now become a effective substitute for compacted clay liner (CCL) as the barrier layer in the cover and liner system in environment protection facilities. GCLs are prefabricated liners which comprise of a thin layer of bentonite bonded to a layer or layers of geosynthetics. The geosynthetics in GCLs are either geotextiles or geomembranes. Geotextiles- based GCLs are bonded together by needle punching, stitch bonding or using adhesives. The main function of geotextiles in GCLs is to keep bentonite in position till the GCL is placed as barrier. Geotextiles used in GCLs are usually made from polymeric materials. Geotextiles from natural fibres such as coir are abundantly available in the state of Kerala and they can be used as substitute for polymeric materials. These natural coir fibres are eco- friendly and less expensive than polymeric materials. But due to their large aperture size, bentonite comes out of cover fabric. A thin layer of polypropylene (PP) felt can be used as an additional material to prevent leakage. In this study different coir geotextile based prefabricated liners are developed by changing the type of coir geotextile and bentonite concentration. The permeability of each of these liners are studied and compared. The permeability of the developed liners was in the range of 10-5 cm/s to 10-6 cm/s.