Recovery of critical metals from dilute aqueous waste streams by adsorption on functionalized biopolymers

Promovendus/a: Joris Roosen

Promotor(en): Prof. dr. Koen Binnemans, Dr. Steven Mullens

The world population has surpassed 7 billion people and we are moving towards an increasingly developed welfare society. But our high standards of living have a huge impact on the environment. Green-tech applications are rapidly being developed to replace fossil fuels by renewable energy, but the quantity of raw materials needed for these sophisticated applications is immense. More and more intensive mining activities for the production of raw materials have led to a situation of resource scarcity. Moreover, primary deposits are geographically concentrated, mainly outside Europe, thus causing geopolitical risks for domestic production. The essential transition towards a low-carbon economy can be secured only as soon as technological metals can be produced self-sufficiently, in a sustainable way. Therefore, new technologies must be developed.

The goal of this PhD was to develop high-performance adsorbent materials from biopolymers and to investigate their value for the recovery of (critical) metals from dilute aqueous waste streams. By physical and chemical modifications to the biopolymer structure, it was aimed to obtain adsorbents with a high potential for application to real industrial process residues. This required a dual focus during the research. On one hand, the synthesis procedures had to be economic, straightforward and easy to scale up. On the other hand, the functionalized materials had to show a high capability for metal uptake, separation and reusability.