How can Swedish WWTPs address the PFAS challenge?
The widespread use and dispersion of PFASs (per- and polyfluoroalkyl substances) is a societal challenge at the global level. PFASs have very poor degradability, and a high risk of negative health and environmental impacts. Further, knowledge about dispersion and separation of PFASs is insufficient. For instance, knowledge gaps regarding PFAS dispersion and separation are particularly large at municipal wastewater treatment plants (WWTPs).
PFAS is an umbrella term for industrially produced chemicals. The thousands of different PFASs are found in everything from fire-fighting foam and cosmetics to impregnated textiles and coated food packaging.
PFASs can spread over large areas, for instance by air and water. However, not enough is known about dispersion pathways and how polluted flows can be stopped.
The role of wastewater treatment plants in PFAS
Municipal wastewater treatment plants are collection points for many of society's emissions, and their role and responsibility as regards PFASs is now under increased scrutiny. Here, a synthesis of both existing knowledge and knowledge gaps, along with guidance and recommendations, can be very helpful. Such a synthesis facilitates making overall assessments of the dispersion pathways and prioritizing the appropriate measures.
IVL has, taking a holistic perspective, examined and answered questions concerning:
- PFAS flows in Swedish society
- The role of wastewater treatment plants as a dispersion pathway for PFASs
- Existing treatment techniques
- How PFAS can be treated in the future, and what synergies can be achieved with treatment of other micropollutants such as drug residues
- Which analysis methods should be used when working with PFASs
- How WWTPs can address the PFAS challenge
Conclusions for future work with managing PFASs
Although certain PFASs are heavily regulated and some separation of PFASs can be done in WWTPs, neither current nor future technologies are sufficient to remove PFASs from society and the environment. PFASs are everywhere around us and will remain so for a long time.
PFASs can only be effectively removed from society and the environment if their introduction by way of products is halted. To avoid shifting the presence of PFASs from one part of the environment (e.g. wastewater) to another (e.g. sludge for spreading on fields), a long-term management of PFASs with incremental separation from the natural cycle will be necessary.
The focus in this separation from the natural cycle should primarily be on heavily polluted land and landfill leachate. Efficient upstream work where measures are taken right at the source should be prioritized even more, to reduce the spread of PFASs by way of sludge fertilization.
Finally, there must be a comprehensive strategy to deal with PFASs as a group, if necessary with measures targetted at particularly problematic substances.
Knowledge synthesis from analysis and survey
With a focus on municipal wastewater treatment plants, knowledge was synthesized following analyses and surveys of sources and transport routes, legislation and possible measures. PFAS flows from Swedish wastewater treatment plants were surveyed, and the PFASs analysed. Based on the knowledge synthesis, recommendations for wastewater treatment plants were developed.
In accordance with one of the project's aims, the knowledge synthesis and the recommendations were presented in an easily comprehensible way, in order to communicate with experts in micropollutant remediation as well as with laypeople.
The projects' benefits for society and for the global goals
The ambition is that the knowledge synthesis will deliver societal benefits by providing information and spreading knowledge, and will assist Swedish wastewater treatment plants in their efforts to improve the separation of PFASs. The efficient removal of PFASs and other micropollutants from the water is one of the most important measures in paving the way for a sustainable and healthy society that does not negatively affect the environment.
The project has not identified any competing environmental goals, but one basic requirement for research and development is that a reduction in emissions to the marine environment is not countered by an increase in chemical use or emissions to the atmosphere.
Goal 3 – Good health and well-being
Helping raise knowledge levels for how PFASs are spread in society is an important part of achieving the goal of Good health and well-being. The survey of PFASs conducted within the study showed clearly that the substances have several emission sources and dispersion pathways. For instance it has become clear that if there is a decrease in the import of PFASs via products and use in industry and business, as well as in atmospheric deposition, the efflux of PFASs via the surface water will also decrease. The quality of the surface water is directly reliant on good health and, ultimately, good well-being.
Goal 6 – Clean water and sanitation
In the project, IVL has compiled and quantified the PFASs for WWTPs, a site where PFASs are not naturally separated. To achieve clean water and sanitation for everyone, we need to determine how and where our water is polluted, before important measures can be implemented. The knowledge gaps IVL is trying to address have concerned supplying municipal WWTPs with information on how they best can manage the problem of PFASs .
Goal 11 – Sustainable cities and communities
Sustainable cities and communities are based on, among other things, access to clean water over time. Identifying pollutants in different types of water, and proposing how these can be handled in the future, i.e. how we can address this challenge, is part of these sustainability efforts.
Goal 12 – Responsible consumption and production
Products containing substances that pollute our environment and our waters must be phased out in the long term. In the project it has become clear that substances produced in industry are also dispersed extensively in the environment. This dispersion also occurs with substances used in the past. Consequently, future consumption should be based on consumption and production that uses other more environmentally friendly and biodegradable chemicals.
PFASs also reach our seas, and thus our marine resources. In this project, IVL calculated that every year, some 600 Kg of PFASs reach the seas in Sweden. This figure must be reduced. IVL hopes that the survey that was developed in the project can provide support in this work.
Reducing the use of PFASs in our society will benefit the surrounding environment, such as marine and land areas. This in turn affects ecosystems and biodiversity, e.g. because we lower the risk of PFASs accumulating high up in the food chain.
Contributions to other global goals
Other global sustainability goals that the work with PFASs will contribute to, directly or indirectly, are Goal 9 – Industry, Innovation and Infrastructure and Goal 13 – Climate Action.