Our research topics encompass both socio-economic and sustainability aspects and different remediation processes depending on several factors. Issues as important as the quantification of contaminant transport, biogeochemical processes and degradation at field scale are being developed at the Université de Liége in Belgium. Natalia Fernandez is one of the early-stage researchers that make up the ADVOCATE team and is working at the Université of Liége. Natalia’s research is exploring links between soil and vadose zone processes for in situ remediation of groundwater. Although risk analysis and mitigation programmes for polluted soil and groundwater are used to understand pollutant fate and transport, certain shortcomings have been identified. Consequently, Natalia is developing an efficient and robust procedure for assessing pollutant transport from the pollution site to the groundwater body.
As well, the groundwater-surface water interface is an important factor when a remediation soil treatment is being developed, that is why Vidhya Viswanathan from EAWAG in Switzerland and Uwe Schneidewind from Flemish Institute for Technological Research in Belgium have to focus their efforts on the studies about the influence of surface water-groundwater interaction and the subsurfaces heterogeneities respectively. In view of that, Vidhya’s project examines the impact of restoration on the function of the river Thur in Switzerland. This is done by looking at diurnal and seasonal changes in flow and water quality. The search will identify and measure different parameters to see how these influence each other, as a descriptor of this interaction between the two environmental systems. In related work, Uwe is investigating which parameters are of importance and how they are related to each other in the context that the groundwater-surface water interface of lowland rivers often shows increased contaminant attenuation potential compared with the adjacent aquifer. For this he is conducting modelling studies to determine reaction rates and hydraulic parameters, and their interdependence across different spatial and temporal scales. The results of both will allow up-scaling of attenuation and identify how variation in these due to heterogeneity affects prediction of attenuation.
Also, when a site is contaminated by heavy metals, those can not be degraded, the only existing risk reduction measures are removal or immobilization using different technologies such as In Situ Bioprecipitation (ISBR). The permeable reactive multi-barrier (PRmB) system is a relatively new technology that Franklin Obiri Nyarko from Hydrogeotechnika in Poland is using for treating specific contaminants, as well as evaluating and enhancing the long term performance of the PRmB systems. The results will play a major role in improving the general understanding and advancing knowledge of both the scientific and tecnical aspects of this technolgy. Whereas Franklin is working with mixed organic contaminants (BTEX) and some heavy metals and is also collaborating with Johana Grajales from AGH University of Science and Technology in Poland too, who is using the same system in her laboratory studies, field work and numerical modelling for removing tetrachloroethylene (PCE) and trichloroethylene (TCE) from Nowa Deba field site. Her first results show that the feasibility studies indicated that the installation of a PRmB system may be effective to reduce TCE and PCE concentration under the site specific conditions.
Based on the results of Franklin, Okasana Voloschenko from The Helmholtz Centre for Environmental Research in Germany will conduct field studies at sites with existing barriers and diffuse pollution to examine up-scaling of design parameters determined previously by Franklin. Moreover, her research explores the role of aerobic and anaerobic microbial processes in the removal of ammonium from contaminated groundwater in constructed wetlands (Cws), using a study site located downstream of the Leuna industrial chemical area in Germany. As well, Ben Doulatyari from EAWAG in Switzerland will interpret the results with multi-scale modelling tools and statistical methods to develop performance-based criteria for the design, monitoring and assessment of sequenced reactive barriers. Also, Ben is studying in the river Thur the dynamics of the vegetartion biomass at different points of the stream, as well as catchment hydraulics, managed aquifer recharge and natural attenuation processes.
To cover all points of view regarding the remediation processes within the project it is necessary to study both the bioremediation processes and the framework, methods and tools which advance the use of these sustainable systems. That is why, on the one hand, Alice Badin from University of Neuchatel in Switzerland is focusing her project on sites contaminated with chlorinated solvents using a useful method of measuring the isotopic signature of solvents that could be a great help in providing a rigorous basis to identify the source and timing of chemicals released to groundwater. And on the other hand, Petra Hesbavna from University of Sheffield in United Kingdom is developing a microbial fuel cells for enhancement of in situ bioremediation of soil and groundwater because the microbial fuel cells are believed to be one of the future sources of sustainable energy. Organic compounds are degraded by microbial metabolism and electrons released during this process are transferred to the electrode of the microbial fuel cell . The Petra’s results show that this groundwater composition will be an ideal inoculum for a microbial fuel cell system, to test the concept as a method for the enhanced bioremediation of contaminated groundwater.
Using geostatistical, probabilistic and numerical modelling methods is possible to evaluate the technologies and approaches used throughout the project. The goal is to develop a unified framework for ISR. In this connection, Juan Pena from Université de Liége in Belgium is focused his research on characterization of the subsurfaces medium, which will lead to new conceptual ways of the modelling that account for the properties of, and interactions between, selected reactive tracers and soil aquifer materials, and on developing optimized single and multiple-well tracer techniques. Likewise, Lukasz Cieslak from University of Sheffield in United Kingdom is exploring interactions between microorganisms in aquifers, which use a range of oxidants to biodegrade organic contaminants. This creates a sequences of zones in contaminated groundwater, which represent different terminal electron accepting processes (TEAP). Lukasz has completed an initial sampling programme to characterise the hydrochemistry and microbiology of an organic contaminant plume fringe at the site, using a series of high-resolution multilevel samplers.
Because the economic aspect is the most important factor for the stakeholders, without being cost-effective the technology will not be introduced within the foreseeable future. Consequently, Alistair Beames from The Flemish Institute for Technological Research is developing a decision-support framework to assist stakeholders in choosing between brownfield revitalization alternatives. Brownfield revitalization planning entails the careful consideration of remediation alternatives capable of reducing contamination level to the required target values, as well as determining the optimal land-use scenario for the remediated site. Also, Alistair is developing the Social Impact Assessment component of the eventual decision-support framework, the focus of the review is on whether the social aspect of sustainability is adequately accounted for in these existing tools.
Finally, my name is Ruth García de la Calle and I am the person that will try to promote the network and bring closer to the public everything relating to the remediation of soil and groundwater to give you an easy scientific understanding about this topic.