The extraction of elements such as Li is increasingly important due to its skyrocketing use in technology. Cost-effective and environmentally friendly methods are desired to meet the growing global demand. As an alternative to mining (the most common extraction method), recovery from geothermal water is being explored. However, this is challenging as many competing ions are present, often in concentrations much higher than the target. Therefore, highly selective methods are required. 

Crown ethers (CEs) have shown excellent selectivity for Li. By binding the CEs to magnetic nanoparticles (MNPs), the entire compound, including the adsorbed target ion, can be extracted from water using an external magnet. Following the desorption of the target ion, which can be induced via a simple pH shift, the MNP-supported CE can be reused. In this project, a “Schwebereaktor” will be used to process large volumes of water. The MNP-CEs will be suspended in the middle of the reactor using external magnets and an upward water sample flow, enabling them to continually adsorb the target ion. This allows for large volumes of water to be processed. This highly selective concentration method aims to be both environmentally friendly, cost-effective and scalable. 

References
[1] Nistler, A et al., Anal. Bioanal. Chem. 2019, DOI: 10.1007/s00216-019-01808-z.

Funding                                                                           Cooperation
AIF-ZIM                                                                            Hydroisotope GmbH