Development of a procedure to identify PFAS immobilisation

for individual and defined immobilisation approaches (PFAS-Immo), Part 2

High-volume sampling of a PFAS-contaminated soil for laboratory testing

The goal of the project is to develop and make available a simple and cost-effective method for the experimental testing of immobilisation measures for PFAS in soils. TZW also performs the trace-analytical determination using LC-MS/MS.

The large-scale soil contamination in the Rastatt/Baden-Baden area (approx. 800 ha) with per- and polyfluoroalkyl substances (PFASs) has a direct influence on various users. These include the gravel industry, which has to remove and potentially dispose of the topsoil to mine gravel and sand. Approaches to remediate or shift the polluted soil have not proven economically feasible due to the chemical properties of the PFASs and the large-scale contamination. Which is why more emphasis is placed on ways to immobilise the PFASs in contaminated soil by adding special agents and thereby direct the soils to specific uses e.g. the construction of privacy screens or noise barriers.

A method to obtain experimental proof is required to evaluate the effectiveness of immobilisation. For this reason, this project will therefore investigate various immobilisation approaches in experiments on three different scales (batch tests, column experiments, lysimeter) and under different conditions (saturated, variably saturated). The time frame of the PFAS concentrations in the experiments is measured via LC-MS/MS analysis and numerically modelled.

The laboratory experiments and the modelling will be performed at the project partner’s premises IWS/VEGAS at the University of Stuttgart. The PFAS trace analysis in the investigated solids and aqueous samples takes place in the TZW laboratory specialised in this field.