Percolation as a single test to assess pollution potential of a waste

Abstract

A new test of percolation under pressure is proposed to estimate the pollution potential of wastes in various scenarios. Depending on the use foreseen for the material, samples can be analysed in a granular or monolithic state. The proposed trial keeps the physical structure of the samples and accelerates the phenomena by applying a pressure variation in order to obtain many important data, such as permeability and the environmental release of species. In this paper, some results of this percolation test are presented for hydraulic-binder-treated gravels and sands that include polluted treated sediments. The results are repeatable and a steady flow is reached for each kind of sample. Incorporation of the waste leads to a drop in the permeability of road materials even though their characterization shows that they are more porous. The capacity to resist aggressive ion penetration can then be estimated. The release kinetics of heavy metals are studied and the environmental release results are compared with data from a regulatory leaching test. Differences can be observed and the percolation test seems to be more sensitive for most of the heavy metals measured.

Keywords:

• environmental assessment
• percolation test
• monolithic materials
• waste valorization road materials

Acknowledgements

The authors would like to thank the Solvay Company, which originated this study, for its financial support for this research.