Transport of organic pollutants in composite liners

Composite liners (a geomembrane in intimate contact with a mineral liner) are frequently used to line landfills and contaminated sites. It is therefore important to characterise the behaviour of these systems. An investigation was undertaken to determine the influence of a mixture of concentrated organic contaminants on composite liner materials taken from test cells that had been dismantled after a 12-year permeation test. The organic hydrocarbons had permeated the HDPE geomembrane and had then migrated or had been adsorbed within the various mineral liners. The obtained concentration profiles indicate that the various mineral layer materials have selective retardation abilities which correspond to the different parameters of the organic compounds as well as of the mineral layer. In addition, contaminant transport in the composite liners tested was modelled and the results of the model analysis compared with measured data. An example (acetone) illustrates the comparative spatial and temporal contaminant concentrations.

The various composite liners investigated offer an efficient system, even under the extreme conditions of the permeation tests.

• 1 INTRODUCTION

• 2 MATERIALS AND METHODS

• 3 RESULTS

• 4 CONCLUSIONS

• 5 REFERENCES