Wednesday, 15 September 2021 - 12:00pm

The Geofabrics University: Performance of Standard and Hybrid Geosynthetic Clay Liners Permeated with Landfill Leachates Containing PFAS

Presented by Daniel Gibbs

Geosynthetic Clay Liners (GCLs) have gained widespread acceptance and use in landfill lining, capping and containment applications due to their uniform quality, ease of use and low permeability to a wide variety of liquids. Their liquid barrier performance can be challenged when in contact with liquids and soils containing high concentrations of multivalent cations or extreme pH. 

Typical MSW landfill leachate chemistries do not often present a challenge for high quality GCL’s in terms of their liquid barrier performance but with a recent focus on Per- and Polyfluoroalkyl Substances (PFAS) in landfill leachates, it is important to consider the transport of these chemicals through GCLs. GCLs are often one of the last lines of engineered defence against the movement of PFAS into the underlying subgrade and groundwater.

This webinar session will include current information about PFAS and the types and levels in Australian landfill leachates, the development of a hybrid GCL containing a very specific activated carbon and how standard and hybrid GCLs perform their role as a liquid and contaminant barrier when in contact with landfill leachates containing PFAS.

Learning Outcomes

  • Introduction to GCLs and Bentonite
  • Introduction to PFAS - types, structure & nomenclature 
  • Environmental and health issues related to PFAS
  • PFAS in landfill leachates
  • Performance of standard GCLs in contact with leachates
  • Introduction to Activated Carbon (AC) of the mechanisms of adsorption
  • Development of a hybrid GCL containing AC
  • Hydraulic and contaminant performance of a hybrid GCL with landfill leachates
  • How to correctly design with and specify hybrid GCL’s with a focus on MQA and CQA analysis

The first Geofabrics University course will officially launch Tuesday 5 October - registration information to come.

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