The R&D project PFAS-Konz is investigating innovative processes such as foam fractionation and precipitation with PerfluorAd for PFAS removal from membrane concentrates.
Due to the limit values in the amended Drinking Water Ordinance for total PFAS-20 and total PFAS-4, which come into force in 2026 and 2028 respectively, many affected water suppliers are currently preparing to expand their respective drinking water treatment plants. To remove PFAS (perfluorinated and polyfluorinated alkyl compounds), activated carbons are currently used in drinking water treatment in Germany or filtered via dense membranes such as nanofiltration or reverse osmosis. Since July 2023, PFAS elimination using capillary nanofiltration has been investigated at TZW with water supply partners in a DVGW-funded project in order to avoid the use of antiscalants (KapillO-PFAS). In membrane processes, however, the discharge of PFAS-containing concentrates into flowing waters without prior treatment is being viewed more and more critically and is becoming increasingly politically relevant. It is therefore essential for the drinking water supply that treatment processes for concentrates are available so that membrane filtration technology can continue to be utilised.
In the PFAS-Konz project, the two technologies ‘foam fractionation’ and ‘PFAS-binding precipitants (PerfluorAd and PerfluorAd+)’ are to be investigated on a laboratory scale in order to assess their general suitability for concentrate treatment. These two technologies are already being used on an industrial scale in the field of contaminated site remediation for PFAS removal from groundwater and are therefore of great practical relevance. However, as the quantities of water to be treated and the water quality differ, among other things with regard to PFAS concentrations, initial tests are required to determine their general applicability. The results of these first tests will be used to determine whether this type of treatment will be expedient in the future for the concentrate quantities produced in waterworks and whether this can be used to meet the current challenge.
