Comprising more than 4 700 chemicals, perfluorinated and polyfluorinated alkyl substances (PFAS) are a group of widely used, man-made chemicals that accumulate over time in humans and in the environment. PFAS are used in non-stick pans, paper products, textiles, firefighting foam, electronics and other products. 

Fig. 1. The contamination of PFAS across Europe. 

Due to their widespread application and use, PFAS are continually released during production, product use, and disposal via point and nonpoint sources into the environment. Over 95% of PFAS are released into the aquatic environment. They are known as ‘forever chemicals’ as they are extremely persistent in our environment and bodies. They can lead to health problems such as liver damage, thyroid disease, obesity, fertility issues and cancer. For nearly one year, Le Monde worked with journalists from 17 media partners to try to measure the extent of this contamination in Europe, and based on thousands of environmental samples, there are more than 17,000 sites in Europe contaminated at levels that require the attention of public authorities (above 10 nanograms per liter). 

Fig. 2. Detection and treatment are two of the main pillars of PFAS problem.

It is therefore evident that the removal of PFAS from the environment is critical. The best available technology (BAT) solutions to treat PFAS in water include granular activated carbon (GAC) adsorption, ion exchange (IX) resins, and nanofiltration (NF) or reverse osmosis (RO) membrane treatment processes. In addition, the United 

States Environmental Protection Agency (EPA) has set a health advisory level of 70 ppt (70 ng/L) for lifetime exposure of perfluorooctanoic acid (PFOA). However, conventional methods could not effectively achieve that low detection limits without the need of ultra-high resolution methods and special pretreatments, requiring high costs. These methods typically require off-site analyses, are time consuming, relatively expensive and matrix-matched calibration standards should be routinely employed. Costs of $300-$600 per sample are prohibitive in routine monitoring and do not allow for widespread sampling and testing of common PFAS.

In this context, the forecasting of PFAS spatial and temporal distribution over the subsurface (soil, groundwater) and surface waters, their cost-effective and sustainable removal and destruction from soils and waters and advanced PFAS detection methods with very low detection limits are three tasks of paramount importance. Three of the pillars of SCENARIOS are related to the development of novel approaches for the numerical prediction of PFAS fate in the subsurface, the effective degradation of PFAS and the rapid, accurate detection of PFAS at very low detection limits.