Project title: KONATES - Design and pilot plant testing for the use of contaminated aquifers for heat management with ATES plants
Underground thermal energy storage in aquifers (Aquifer Thermal Energy Storage, ATES) is able to make an important contribution to seasonal heat management in urban areas. In cities, especially shallow aquifers are often contaminated with pollutants and cannot be used for drinking water supply. Within the KONATES cooperation project, the cyclic operation of an ATES in contaminated aquifers is to be investigated in order to combine thermal management with possible groundwater remediation. As case studies serve the "Wissenschaftspark Leipzig" (Saxony) and individual cases of damage in the area of the Ecological Major Project (ÖGP) Bitterfeld-Wolfen (Saxony-Anhalt), which show typical contaminations for urban and industrial sites.
Already available site data will be evaluated in preparation for the planned ATES pilot plant at the "Wissenschaftspark Leipzig" and completed by sampling and supplementary investigations at the site. Other work priorities include the development of high-resolution numerical models, the drilling of monitoring and infiltration wells, and the installation of the aboveground pilot plant with heat exchanger and cleaning module. In addition, a site-specific exploration and monitoring concept is being developed, along with geochemical and microbiological baseline monitoring of the Leipzig site. Furthermore, a test phase of the ATES pilot plant is planned in order to test its chemical-physical clean-up performance. Surface treatment of contaminated groundwater will also be tested, supported by laboratory and pilot plant tests for the hydrochemical amendment of the groundwater. Investigations regarding the efficiency, kinetics and stability of the processes are planned to enable the optimization of operating parameters and the determination of performance limitations of the ATES pilot plant. Lab and field studies on the impact of ATES operations and analysis of pollutant concentrations for major and trace elements as well as degradation of volatile halogenated hydrocarbons will be executed. Furthermore, the determination of possible changes in the biocoenosis in groundwater and sediment samples will be performed, along with the identification of key organisms for pollutant degradation. Concurrent with the field investigations, laboratory analyses are being conducted to predict the biogeochemical effects of heat storage. For this purpose, also samples of selected damage cases of the Bitterfeld site are considered. Geochemical studies of important processes such as precipitation, clogging, gas formation, biofouling, and biocorrosion that may affect the operational safety of ATES systems will also be investigated. It is planned to develop suitable monitoring, mitigation and regeneration measures. Finally, a guideline (manual) with recommendations for combining seasonal heat storage with remediation measures will be prepared.