Dr.-Ing. Marcus Heilmann – Innovative process to recover rare earth elements
Dr.-Ing. Marcus Heilmann – Innovative process to recover rare earth elements
The aim of this project was to develop an innovative sorption process based on biomass of phototrophic organisms for the recovery of rare earths (REEs) and other valuable metals from alternative sources. The process should represent an environmentally friendly alternative to conventional methods and be suitable for highly diluted solutions of rare earths and metals.
Of the 37 species examined in the primary screening, three representatives were selected on the basis of their maximum sorption capacity for REEs: the cyanobacterium Calothrix brevissima, the green alga Chlorella kessleri and the moss Physcomitrella patens.
Further characterization of the biosorption of the selected candidates showed that hydroxyl-rich structures of the biomass, especially polysaccharides, play a role in the sorption of REEs. Adsorption isotherms confirmed that in particular P. patens and C. bevissima can effectively adsorb neodymium even from very dilute solutions. In addition, the pH value and the composition of the samples intended as REE source have a relevant influence on the biosorption of the target elements (neodymium and europium). For example, the pH optimum of Qmax,Nd for P. patens was between pH 3 and pH 6, while for C. brevissima it was only between pH 5 and pH 6. All three species showed the highest affinity for gold and lead, followed by the REEs.
Finally, the investigations of the dynamic sorption of REEs from model samples on biomass immobilized in a cartridge showed that they can be bound very efficiently, even in the presence of impurities such as nickel, copper, lead or iron.
This project is carried out in cooperation with Prof. Dr. Thomas Brück, Werner Siemens-Chair of Synthetic Biotechnology, TU Munich, within the framework of the ForCycle-Consortium financed by the Bavarian State Ministry of Environment and Consumer Protection (project number: BAF01SoFo-66947).
Publications:
, , : Towards rare earth element recovery from wastewaters: biosorption using phototrophic organisms. Appl Microbiol Biotechnol 105, 5229-5239.
Heilmann M, Jurkowski W, Buchholz R, Brueck T, Becker AM (2015): Biosorption of Neodymium by Selected Photoautotropic and Heterotropic Species. J Chem Eng Process Technol 6: 241
Glemser M, Schmidt J, Heining M, Becker AM, Buchholz R, Brueck TB (2016): Application of light emitting diodes (LEDs) in cultivation of phototrophic microalgae: current state and perspectives. Appl Microbiol Biotechnol 100(3):1077-88.
Jurkowski W, Heilmann M, Becker AM, Buchholz R, Brück TB (2020): Terbium Excitation Spectroscopy as a Detection Method for Chromatographic Separation of Lanthanide-Binding Biomolecules. ACS Omega, 5 (42), 27050-27056.
