Electrokinetics removes rare earth metals from polluted soil

EKRemedi8s aims to establish electrokinetics (EK) as a soil remediation technology able to extract rare earth elements (REE) from polluted sites and reintroduce the metals back into industrial production, contributing to the circular recovery of REE. REE are critical to the modern economy and its sustainable mining is essential for a Circular Economy (CE).
Metal contaminated sites are spread across Europe being the most recurrent (35% of the total sites) and constitute the number one concern to the remediation industry. Nowadays, the main solution for these sites is landfill2. However, they contain metals that can yet be used as commodities in emerging carbon-free energy industries, such as photovoltaics, metals which are currently being mined from virgin sources. EK is the only remediation technology that is able to effectively extract metals in-situ with minimal soil disturbance , and therefore, the best available technique capable of closing the gap for contaminated soil metal (re)cycling. EKRemedi8s overarching goal is to:
• Explore EK technology for the extraction of REE from contaminated soils.
The project combines experimental, numerical and conceptual modelling to demonstrate EK’s role as a resource recovery tool for REE. One of the key features of the project will be to supply training in (i) REE chemistry and (ii) model the life-cycle analysis (LCA) of EK for REE extraction from soil.
This project will serve as a proof-of-concept for developing a methodology to extract REE and purify them to be reused in the industry of choice. A database will be developed to understand the best experimental design for the removal of specifically tellurium and lanthanum REEs. The optimized parameters will be adopted to perform the EK experiments. Once metals are extracted and in a dissolved form in the electrolytes, batch experiments will be carried out to precipitate the metals back to a solid commercial form. Lastly, quantitative and semi-quantitative method – LCA – will be used to evaluate EK sustainability and efficiency for REE recovery and create the grounds to establish a tool that will enable stakeholders to evaluate EK as an extraction technique for REEs from polluted sites. This feature delivers the capacity to increase the European remediation community competitiveness, both academic and industrial, contributing to the ambitious goal for a CE.
The fellowship under the H.C. Ørsted Postdoc program will be the reintegration and consolidation vehicle for the researcher to return to the European research environment. The research-based training provided by the project will set the scene for the researcher to fuse her already multidisciplinary background into an interdisciplinary, holistic approach to curate REEs from an otherwise waste resource. The project lies perfectly within the research strategy of one of DTU Byg´s strongest research teams, ZeroWaste Byg. Her training in REE and her previous expertise in geochemistry will be key for understanding REE chemical processes and mechanisms in soils that this project proposes, and aggregate to the Departments’ demands regarding ongoing research on electric fields applications to building and waste materials.