Post on 16-Jan-2016
description
LANDFILL LINERS
A landfill liner or composite landfill liner, is intended to be a low permeable barrier, which is laid down under engineered landfill sites.
DEFINITION
to isolate the landfill contents from the environment
to protect ground water from pollution
to protect soil from contamination
NEED OF LANDFILL LINERS
VARIOUS TYPES OF LINERS
CLAY GEO-MEMBRANE HIGH DESITY POLYTHENE (HDPE) GEONET GEOTEXTILE
To protect the ground water from landfill contaminants, clay liner are constructed as a simple liner that is two to five feet thick.
CLAY
Natural clay is often fractured and cracked. A mechanism called diffusion will move organic chemicals like benzene through a three feet thick clay landfill liner in approximately five years. Some chemicals can degrade clay.
SOME DEMERITS OF USING CLAY AS LINER
These liners are constructed from various plastic materials, including polyvinyl chloride(PVC). This material is strong resistant to most chemicals, considered to be impermeable to water.
GEO-MEMBRANE
High Density Polythene is a hydrocarbon polymer prepared from ethylene/petroleum by a catalytic process.
HIGH DENSITY POLYTHENE(HDPE)
Geonet is plastic net like drainage blanket used in landfill liner in place of sand or gravel for leachate collection.
GEONET
Geotextiles are permeable fabrics which, when used in association with soil, have the ability to separate, filter, reinforce, protect or drain.The geotextile layer is used to minimize the intermixing of the soil and soil or gravel.
GEOTEXTILE
SINGLE LINER SYSTEM
COMPOSITE LINER SYSTEM
DOUBLE LINER SYSTEM
TYPES OF LINER SYSTEM
Single liners (Box-1)consist of a clay liner, geo-synthetic clay liner or geo-membrane liner.
SINGLE LINER SYSTEM
Composite liner system consist of a geo-membrane in combination with a clay liner(Box-2).It is more effective at limiting leachate migration into subsoil than either a clay liner or a single geo membrane layer.
COMPOSITE LINER SYSTEM
Double liner consists of either two single liners, two composite liners, or a single and a composite liner (Box-3).The upper(primary) liner usually function to collect the leachate, while the lower(secondary) liner acts as leak-detection system and backup to the primary liner.
DOUBLE LINER SYSTEMS
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