PFAS – from miracle cure to widespread pollutant
Per- and polyfluorinated alkyl substances (PFAS) have long been considered technological miracle cures. Today, they are the focus of environmental and health protection, as they have proven to be extremely durable and widespread. At the Hanover site, Prof. Burmeier Ingenieurgesellschaft mbH BIG – a member of the SIERA Alliance – is intensively dealing with this pollutant group. The following contents shed light on the origin, properties, environmental behaviour and remediation approaches of this group of substances and show why PFAS represent one of the major challenges of modern environmental technology.
Background and areas of application of PFAS
Due to their water, dirt and grease-repellent properties, representatives of per- and polyfluorinated alkyl substances (PFAS, also PFC – per and polyfluorinated chemicals) can be found in a variety of everyday products such as outdoor jackets, Teflon pans or coffee-to-go cups, but also in firefighting foams. The PFAS group now includes more than 4,700 different substances.
From a chemical point of view, these are organic compounds with different chain lengths, in which the hydrogen atoms have been partially (polyfluorinated) or completely (perfluorinated) replaced by fluorine atoms. These carbon chains also have acid or alcohol groups. The connection between the carbon and fluorine atoms can only be destroyed again with a high amount of energy, e.g. in waste incineration plants. Complete bacteriological or photochemical degradation is not possible.
Environmental behaviour and risks
Since these substances do not degrade in nature and thus remain in the environment for a long time and also have a high degree of mobility, they pose a significant environmental problem. Some PFAS can accumulate in plants, animals and humans and are also harmful to health.
PFAS can be introduced into the environment, for example, from the exhaust air from industrial processes, but also from the domestic living environment, e.g. from impregnation sprays, via vapours from dirt-repellent textiles or via wastewater and resulting sewage sludge, and thus enter the food chain. PFAS also become problematic because some of them bind to proteins in the human body and are sometimes passed on to the child in increased concentrations during pregnancy or breastfeeding.
Global distribution of PFAS
In addition to Europe-wide, in some cases increased contamination of groundwater by PFAS, investigations showed that they were basically detectable everywhere in the soil. Studies in the Arctic show that PFAS can be detected in freshwater as well as in marine waters, glaciers, air and snow, but also in fish, whales, birds and phytoplankton.
With increasing scrutiny, PFAS are detected in more and more studies. It can be assumed that this group of pollutants is widespread.
Restructuring approaches and responsibility
At present, PFAS-contaminated soils can only be remediated by high-temperature treatment, but in the case of contaminated groundwater, cleaning with activated carbon is generally possible.
PFAS is just one group of many pollutants that are to be removed from the environment as part of remediation measures in order to make our world a little better. Engineering for a Better Tomorrow.
