In this project, scientists will conduct research into fundamental processes that are relevant for PFAS behavior in water and soil. The knowledge gained will be translated into possible remediation solutions. Possible remediation solutions can be tested in the laboratory at the Uithof and on the “PFAS field” at the Münsterlaan in Utrecht. This project contributes to knowledge development and will share knowledge gained with stakeholders.
The growing population and urbanization puts increasing pressure on our subsurface environment. In respond to the demands for underground constructions, large excavations have been constructed in recent years which are often deep and sometimes located in the vicinity of contaminated soils and in varying groundwater qualities. To obtain dry working spaces below the water table, excavation sites are typically sealed against the inflow of groundwater by applying silicate grouting.
Silicate grouting is injected as a fluid phase into the designated part of the soil and subsequently hardens over several hours. After that, silicate grouting begin to erode over time. The time scale and the controlling erosion mechanism depend strongly on the groundwater flow, dissolved components, and chemical reactions, and may range from several months to 10’s of years. While silicate grouting is being more-and-more used beyond their traditional limits of usage (in deeper and larger construction pits and under more complex environmental conditions), a thorough scientific understanding of the erosion mechanisms is still lacking. The reliability of silicate grouting under physical and chemical subsurface conditions remains elusive and is often based on very site-specific experiences. This lack of understanding poses a major problem for contractors, project management and local governments as a failed silicate grout results in time delays, large costs and mostly deleterious impact on the subsurface environment.
Microbiomes are the sum of microbes in any defined location, like our gut, our skin, surface of a plant leave, a rock, etc. They play an active but still underappreciated and less explored role in the environment, despite potentially high economic and ecologic significance. In environmental applications, microbes degrading chemicals in soil and groundwater have a high potential to provide eco-friendly and cost-effective solutions to clean up contaminated sites. In Europe approx. 324,000 severely contaminated sites exist and many more with less severe but still substantial contamination that require clean-up like fuel stations.
The EU consortium project MIBIREM has the objective to adapt and streamline microbiome science to the needs of applications, to exploit microbiomes for bioremediation, creating and applying a TOOLBOX to identify, analyse, cultivate and up-scale microbiomes, while ensuring safety and policy alignment.
Bioremediation by use of microorganisms is cost-effective and eco-friendly to remediate sites polluted with organic contaminants: no net water extraction, no extensive on-site treatment plant, no waste and no transport to and treatment by an off-site soil cleaner. Key for a successful application of bioremediation is the understanding and control of the microbial networks that lead to degradation of contaminants. This requires a detailed knowledge of the interplay between the degrading microbiome and chemical and physical site characteristics, and tools to identify and monitor bacteria within microbiomes that actively clean up polluted sites.
The role of the research group at UU is the development of a prediction tool for enhancement and feasibility evaluation of bioremediation. A successful application of bioremediation requires the understanding and control of the microbial networks that lead to degradation of contaminants and the interplay between the degrading microbiome and chemical and physical site characteristics. Numerical simulation can provide valuable knowledge on the processes going on at a field site, like groundwater flow and transport of dissolved substances as well as geo-chemical processes like adsorption and biodegradation. Combining simulations on groundwater flow, contaminant transport and chemical reactions allows making predictions on amounts, locations and time scales of natural biodegradation and bioremediation. Besides, multivariate (statistical) analysis of field observation data can provide guidance on feasibility of bioremediation by evaluating the amount of natural biodegradation taking place. Thus, a combination of statistical data-analysis of observational data with predictions by numerical simulations, can be used for decision support on bioremediation for field sites.
Project Involvement and PhD-(co)-supervision