The technology for purifying drinking water from PFAS is tested at Hammarby Sjöstadsverk. Photo: Andriy Malovanyy
Large-scale test of new method for the removal of PFAS from drinking water
Laboratory experiments testing a new technology for purifying drinking water from PFAS have shown good results. The technology is now being tested on a larger scale at IVL and KTH’s joint research facility at Hammarby Sjöstadsverk.
PFAS is a group of chemicals used in the manufacture of a wide variety of products, for example fire foam. Because these substances do not degrade easily, they accumulate both in nature and in humans. Studies show that high levels of exposure can be linked to several negative health effects and diseases. High levels of PFAS have previously been found in drinking water and water catchment areas across Sweden.
– Problems around PFAS in drinking water are endemic in many places in Sweden as well as in other countries. Solutions are needed and those of us working with research and technology development are hopeful of being able to contribute, says Andriy Malovanyy, researcher and project manager at IVL Swedish Environmental Research Institute.
Researchers at KTH in Stockholm working under the Mistra TerraClean programme have developed a technology that in laboratory experiments has removed over 90 per cent of PFAS. This technology will now be tested on a larger scale at the Hammarby Sjöstadsverk research facility to find out whether a good degree of reduction can also be achieved in larger volumes of water, reflecting real conditions, and over a longer period of time.
The pilot tests in Hammarby Sjöstadsverk have been carried out using equipment developed by the Stockholm Water Technology company. The experiments will provide important information about the capacity and resource consumption of this technology, and form the basis for life cycle assessments made by IVL and RISE.
The technology used to remove PFAS treatment is similar to the that used to desalinate seawater.
– We have modified CDI technology to make it work with PFAS. The technology is based on active carbon pipes that are rolled up like cigars to capture the PFAS pollutants, says Joydeep Dutta, professor of materials and nanophysics at KTH, responsible for developing the technology.
In the pilot experiments, PFAS is added to tap water at the same levels as those in Uppsala’s water supply. In addition to the purification itself, researchers will also investigate what happens to the PFAS contaminants once they have been separated from the drinking water.
– Purified water from laboratory-scale experiments has been analysed for possible degradation products. We found very low levels, close to detection limits, of only five of 200 possible PFAS degradation forms. This suggests that PFAS is likely to be almost completely mineralized. It will be exciting to see if we can get the same good results in the pilot experiments as well, says Raed Awad, researcher at IVL who is studying degradation mechanisms in the project.
Both electrochemical degradation and concentration are tested. IVL and RISE will analyse the purification from a life cycle perspective and determine which substances are formed during capture. The tests at Hammarby Sjöstadsverk are ongoing until September.
For more information, please contact:
Andriy Malovanyy, firstname.lastname@example.org, +46 (0)10-788 68 74
Award for world-class achievements in the field of water research
The project has also been recognized by the VA-Fakta (Waste and Water Facts) industry initiative, which each year awards a prize to municipalities, companies and research projects that have contributed to issues around water in Sweden.
This year’s winner is the Mistra TerraClean consortium, which “through research contributes concrete, technical solutions that provide citizens with clean water, free from hazardous PFAS substances”.
Mistra TerraClean is funded by the Mistra research foundation. It is led by KTH in collaboration with IVL and multiple research institutes and companies.