Tailoring adsorbents and biocatalysts for sustainability challenges
Abstract
Solid adsorbents constitute a promising alternative in answering to the request for improved sus-tainability of industrial processes today. One of the principal routes on this path is recycling of critical elements and purification of both wastewater and drinking water. Improved functionality requires tailoring of materials, using both suitable bearing matrices and the active ligand layers. Such construc-tions are most often hybrid materials with an inorganic or biopolymer matrix covered with grafted species specifically binding to target components. One of the principal bottlenecks in recycling of critical elements is separation of Rare Earth Ele-ments (REE) from Late Transition Metals (LTM), and especially, LTM present together in many elec-tronic, magnetic and battery materials from each other. Selecting a proper ligand function permits to implement principally different binding mechanisms for REE and LTM, leading to enhanced selectivity both on adsorption and, especially, on desorption steps [1-2]. Ligands influencing oxidation states of LTM can offer a possibility to separate individual constituents of, for example, anodes of Li-ion batter-ies such as Co and Ni [3]. In the challenges for water purification two major problems have been identified. One of them is associated with accumulation of persistent organic pollutants (POP) such as pharmaceuticals. An effi-cient biocompatible and soft chemical route is oxidation of POP applying biocatalysts, most attractive-ly, peroxidase enzymes. Maintaining the activity of the latter requires their protection. As a sustainable encapsulation matrix for enzyme biocatalysts can be used natural porous silicates such as LECA, Per-liteTM, or silica gel produced from flying ash [4]. Another alternative for matrix material can be offered by purposefully constructed Metal-Organic Framework (MOF). Such materials have been produced via structural transformation and exfoliation of MOF formed by REE cations and benzene-tricarboxylic acid. The enzyme molecules were adsorbed on MOF nano sheets and built into microparticles by po-rous silica coatings [5]. Another kind of POP is Per- or Polyfluorinated Organic Substances (PFAS). Their removal and ac-cumulation were carried out with complex polycationic functional layers [6]. References [1] A. Vardanyan, G.A. Seisenbaeva, et al., Nanomat., 2022, 12, 974.. [2] T.C. Breijaert, G.A. Seisenbaeva, et al., Dalton Trans., 2022, 51, 17978–17986.. [3] M. Laki´c, G.A. Seisenbaeva, et
