Persistent and mobile organic chemicals (PMOCs) in groundwater – Investigation of persistence as basis for the assessment and reduction of PMOC exposure in groundwater

• Applicant: Qiuguo Fu, Ph.D., since 6/2022
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 437788391

Persistent and mobile organic chemicals (PMOCs), such as p-toluenesulfonic acid, p-toluenesulfonamide, sulfanilic acid and dimethylbenzenesulfonic acid were shown to occur in groundwater. This is due to their remarkably high mobility: Once the chemicals are emitted to water, they are transported quickly through soil and subsoil. This mobility is a unique substance property among organic chemicals and pollutants. The chemical analysis of PMOCs is very challenging because of their low sorption characteristics, which causes a distinct knowledge gap. Worldwide only a few research groups are able to quantify PMOCs in multi-chemical methods. Within a first comprehensive research project led by the Department of Analytical Chemistry at the Helmholtz Centre for Environmental Research GmbH – UFZ, novel analytical methods for PMOCs were developed. Using these methods, the occurrence of a multitude of PMOCs in groundwater in the ng/L to µg/L range was demonstrated for the first time in 2019.Until now, the persistence of chemicals in groundwater is not evaluated in a regulatory context (see e.g. REACH Regulation (EC) No 1907/2006: European chemicals regulation). However, several studies have shown that the persistence of organic chemicals in groundwater can be especially high. This also applies to the four PMOCs mentioned above, which show half-lives of more than one year in aquifers – although they are assessed as non-persistent using the current REACH persistence criteria. Fundamental research is crucial and urgently needed to investigate the fate and persistence of PMOCs in groundwater and with that the exposure situation for humans and the environment.This project will develop and apply experimental tools to investigate the fate and persistence of PMOCs in groundwater. This includes further development of analytical methods, a monitoring study as well as the development of a test system to evaluate the persistence in aquifers and aquifer sediments under different redox conditions. Therewith, the exposure situation of PMOCs in groundwater can be investigated and assessed. The developed experiment tools and the knowledge gained in the proposed project could form the scientific basis needed to expand the REACH regulation for mobile chemicals rapidly reaching groundwater.

• DFG Programme: Research Grants
• Co-Investigators: Dr. Peter Börke; Professor Dr.-Ing. Thorsten Reemtsma; Dr. Carsten Vogt
• Ehemaliger Antragsteller: Dr. Urs Berger, until 5/2022