Blauwe Bagger tests PFAS removal from dredged sediment
What if contaminated dredged sediment no longer had to be treated as waste, but could instead be reused as a valuable raw material? With this question, start-up Blauwe Bagger signed up for the Deltares SME Challenge. By taking part in the challenge, start-ups and small and medium-sized enterprises (SMEs) are given the opportunity to test their innovative design concepts in Deltares’ experimental facilities, guided by experts in the field.
Blauwe Bagger is working towards a circular future in which raw materials are not lost. Since its establishment in 2022, the company has focused on developing new applications for dredged sediment. As dredged material increasingly contains PFAS and therefore has to be disposed of, the Dutch dredging industry faces a major challenge.
Participation in the SME Challenge gave Blauwe Bagger the opportunity to investigate whether – and how – PFAS can be effectively removed from dredged sediment, with the aim of enabling reuse.
Research in the Delta Lab
Under the supervision of Arjan Wijdeveld, soil and groundwater quality specialist at Deltares, Abbe Hekkert and Yannick Laret of Blauwe Bagger were able to investigate in Deltares’ Delta Lab what does and does not work when it comes to PFAS removal. The research focused on PFAS—persistent chemical substances that bind to dredged sediment and are difficult to break down—and on ways to release these substances from the material.
Some of the PFAS end up in the water released during dredging. By passing this water through various filter materials, it became clear to what extent the contamination could be retained. This form of filtration demonstrated that PFAS concentrations can indeed be reduced.
In addition to working with water, the solid component of dredged sediment—the clay—was also examined. PFAS strongly binds to these fine soil particles, making it particularly difficult to remove. Tests explored what happens when this clay is heated. The experiments showed that PFAS compounds such as PFOA and PFOS are no longer detectable in the material at temperatures below 600°C.
This result is promising, but it does not mean that the PFAS are broken down: they evaporate and may re-enter the environment elsewhere. Further research is therefore required, including into preventing emissions to the air, combining separation techniques with lower temperatures, and assessing the energy demand of the process.
The thermal treatment indicates that heating is a promising method for making contaminated dredged sediment suitable for reuse, but that additional research is needed. These insights provide Blauwe Bagger with valuable guidance for a more circular application of dredged material.
Thanks to the SME Challenge, we gained access to knowledge and facilities that would normally be out of reach for a start-up. The insights from Deltares’ Delta Lab have genuinely taken our approach to PFAS removal to the next level.
Abbe Hekkert, Blauwe Bagger
New Insights for a Circular Dredging Sector
The initial results help define the next steps. They show that further research is needed to optimise thermal treatment, but also that it is possible to gradually make dredged sediment increasingly free of PFAS.
This opens up new perspectives for technologies that contribute to a more circular future for the Dutch dredging industry, in which valuable materials are preserved and environmental impacts are reduced.
Deltares will continue this research together with Hydrogenium within a TKI programme (Top Consortium for Knowledge and Innovation). It will therefore certainly be worth following the new insights and results that emerge from this collaboration.
This case fits well with Deltares’ mission: testing innovative solutions to complex challenges related to water, soil and the subsurface, and supporting entrepreneurs who are developing sustainable applications with societal impact. The Deltares SME Challenge provides the space to test new ideas under realistic conditions and to develop knowledge that helps move the sector forward.
Register for the SME Challenge 2026
The experience of Blauwe Bagger demonstrates what participation in the Deltares SME Challenge can deliver: insight into what works, clarity on next steps, and a concrete move towards practical application.
Registration for the SME Challenge 2026 ends on 31 May 2026. Start-ups and SMEs with an innovative design concept in the field of water, soil or the subsurface are invited to register and take their idea one step further
You have not yet indicated whether you want to accept or reject cookies. This means that this element cannot be displayed.
Or go directly to:
Sign up for the Deltares SME Challenge