Assessment of soil contamination and ecotoxicity by the use of an ascending flow percolation - bioassay approach

Abstract : Soil contamination and subsequent ecotoxicity are to be assessed by the use of appropriate methodologies allowing high repeatability and reproducibility. Non-direct methods consist in preparing either lixiviates or percolates which can be analysed for chemical contaminants and whose toxicities on aquatic organisms may be further determined. During experimental water percolation through soil columns, the movement of water is generally due to natural gravity. Here we proposed a complementary method in which an ascending water flow through the soil column is created. This system was developed in order to minimise boundary flow during percolation, which may result in improving repeatability and reproducibility of the aqueous extraction. In this work, the ascending flow percolation method was used for studying soils sampled from 2 contaminated sites. The resulting percolates were then tested for contaminant concentrations, ecotoxicity and genotoxicity.