PFAS-Contaminated Soil Site in Germany: Nontarget Screening before and after Direct TOP Assay by Kendrick Mass Defect and FindPFΔS.

Soil contaminations with per- and polyfluoroalkyl substances (PFAS) are of great concern due to their persistence, leading to continuous, long-term groundwater contamination. A composite sample from contaminated agricultural soil from northwestern Germany (Brilon-Scharfenberg, North Rhine-Westphalia) was investigated in depth with nontarget screening (NTS) (Kendrick mass defect and MS fragment mass differences with FindPFΔS). Several years ago, selected PFCAs and PFSAs were identified on this site by detection in nearby surface and drinking water.

Long-term behavior of PFAS in contaminated agricultural soils in Germany.

PFAS contaminated compost materials have been applied over the last few decades to agricultural fields in Germany, resulting in large-scale diffuse PFAS plumes. The leaching behavior of PFAS from the first two identified contaminated agricultural sites in Germany were investigated, one at Brilon-Scharfenberg, North Rhine-Westphalia Site (BS-NRW), and the other at Rastatt/Mannheim, Baden-Württemberg. The specific objectives of this study were to assess the longevity of the PFAS agricultural sources and compare standardized column percolation tests to long-term leaching of PFAS from contaminated sites.

Increasing electron donor concentration does not accelerate complete microbial reductive dechlorination in contaminated sediment with native organic carbon.

Experiments with Fe(III)-rich, chloroethene-contaminated sediment demonstrated that trichloroethylene (TCE) and vinyl chloride (VC) were completely reduced to ethene regardless of whether electron donor(s) were added at 1 × stoichiometry or 10 × stoichiometry relative to all-electron acceptors. Unamended controls uniformly reduced TCE to ethene with a mean time to complete dechlorination (operationally defined as the presence of stoichiometric ethene production) of 79 days. Adding 1 × and 10 × acetate hindered the rate and extent of TCE and VC reduction relative to unamended controls, with several only partially reduced when the experiments were terminated.

Long-term mass flux assessment of a DNAPL source area treated using bioremediation.

This study assessed the long-term effectiveness of bioremediation as a remedial strategy for a chlorinated, ethene dense, non-aqueous phase liquid (DNAPL) source area, consisting of a higher- and a lower-permeability zone at Alameda Point, California. The evaluation was performed over 3.7 years after cessation of active source area bioremediation using passive flux meters (PFMs), push-pull tracer tests, and soil cores.