Environmental problemsGroundwater and surface water are often contaminated via soil and sediment in industrial and urban areas due to all kind of economic activities. Research is focused to technological measures that can be taken to remove contaminants or to reduce human and environmental risks. The highlight of the research is on organic micro pollutants.
Bioavailability problemsRemediation at contaminated sites is often limited due to a lack of (bio)availability of contaminants leading to high residual concentrations in soil and sediment after (bio)remediation leading to a prolonged contamination of groundwater and surface water. This often leads to stagnation in redevelopment of brown fields (former industrial areas) and residential areas.
Toxic concentrations in source areasAt highly contaminated sites, concentrations in the source zone are toxic to microbial life and therefore hamper biodegradation processes, leading to stagnation of the remediation process.
Polluted dredged sediment
Dredged sediments are often contaminated with organic micro-pollutants like PAH, PCB and TPH. Storage of this material in depots leads to public resistance. Climate change increases the need of dredging sediments to avoid flooding risks. New approaches are desired.
Our solutionsRisk assessment & risk reduction
Transport of VC and toluene from contaminated sources in the groundwater to crawl spaces beneath buildings is studied by mechanistic modeling and experimental research to be able to quantify maximal risks of these compounds. Microbial conversion at field conditions is mimicked in lab experiments to find out whether transport rates into groundwater and crawl spaces can be compensated by bioremediation.
Sediment Risk reduction by Activated CarbonRecently a reduction of bioavailability of PAH by Black Carbon is reported. In this research engineering options on addition of Activated Carbon (AC) to contaminated sediment are studied aiming at risk reduction and even partial remediation for production of AC-treated sediment valid for reuse as building material. This may lead to minimization of the use of sediment depots. Together with AEW ecotoxicological effects of contaminated sediments and AC are studied as well.
Coupling ISCO and BioremediationSource zones of contamination can be well treated with the In Situ Chemical Oxidation (ISCO) technology since about five years. In our research we aim at minimization of use of chemicals by coupling ISCO to bioremediation. In this concept redevelopment of brown fields can directly occur as risks of hotspots are removed, whereas the former source zone and the plume area are bioremediated below the newly built environment for several decades thereafter.
Soil-energy and improvement of groundwater qualityUnderground energy storage for reduction of Greenhouse gas emissions by the Aquifer Thermal Energy Storage (ATES) is combined in this concept with Accelerated Natural Attenuation (ANA). As rule of thumb it is known that every 10oC temperature increase will lead to a doubling of biodegradation rate. Technological aspects as well as implementation of this new combined technology by using the “regional ecological footprint reduction” concept will be studied.
Our approachThe studies in our research group are directed to understanding of mechanisms that are limiting relevant processes in remediation of soils and sediments. The research is in the field of Environmental Technology and links disciplines like microbiology, analytical chemistry, soil science, chemical technology and organic chemistry.
Laboratory research is performed in batch and continuous studies with ‘real’ contaminated soils and sediments.