They seem to be on everyone’s lips right now (oops!): PFAS – per- and polyfluorinated alkyl compounds. The German TV program ARD “Panorama” shortly reported under the headline “The poison of the century” and asked why these chemicals are still allowed at all.

(https://programm.ard.de/TV/Programm/Sender/?sendung=281064000778195)

PFAS are industrially manufactured substances that repel water, dirt as well as grease and can withstand different temperatures. They are used primarily in industrial or consumer products and are found in non-stick coatings as well as functional clothing, cosmetics, and firefighting foam. But once in the world, they are considered almost indestructible, accumulate in nature, and cause enormous damage. Even in the smallest amounts, they are extremely harmful to health and can cause various types of cancer, hormonal disorders, and birth defects. Like microplastics, PFAS are found everywhere, now detected in the blood of most U.S. citizens, in breast milk, and even in wildlife in the Arctic. If the results of a new Swedish study are to be believed, even the world’s rainwater would be considered undrinkable due to excessive PFAS concentrations.

Even our drinking water contains traces, as some PFAS are highly soluble in water and thus enter groundwater. Thus, some groundwater catchment areas are already contaminated with PFAS over large areas, for example in German areas around the towns Altötting or Rastatt. Since PFAS are relatively newly discovered micro-pollutants, there has only been a kind of limit value since 2020, above which the concentration with PFAS is considered “possibly hazardous to health”. Due to the persistence of the substances, PFAS concentrations are expected to increase in the coming years. Some refer to PFAS as “environmental toxins for the ages.”

Removing PFASs from drinking water

Although the compounds can be successfully reduced under certain conditions with an activated carbon stage in drinking water treatment, only few water plants currently have such a treatment stage.

The quickest way to tackle the problem is with a dedicated drinking water filter with activated carbon at home. Thus, in addition to its membrane filter systems, Seccua also offers a Seccua biofilter filled with granular activated carbon. The pollutants are removed from the water not mechanically, but by the physical-chemical process of adsorption (binding), in which the substances accumulate on the surface of the activated carbon. The new optimized model of the biofilter, soon to be available, will have an even bigger activated carbon volume and surface area and thus even better filtering capacity.

When to change the filter depends on the local load of the respective tap water, but the planning target is 3 years. An exact life time will be determined through testing and is also case depended as not only PFAS, but the total sum of all pollutants should be considered.