Optimalizace konsorcia mikroorganismů k zpětnému získávání alkalických kovů z kovonosných prachových odpadů

Abstract

The dissertation focuses on the use of microorganisms for the recovery of rubidium and caesium from secondary - waste sources. The input substrate used was dust from the sintering process with a high content of a wide range of metals, which was recovered in 2018 - 2020 from ArcelorMittal Ostrava a.s subsequently Liberty Ostrava a.s. In the experimental bioleaching processes, different species of microorganisms were applied in two stages in order to assemble optimal consortia for the release and bioaccumulation of the studied alkali metals. In the bioleaching processes, microorganisms originating from the environment of lagoons, tailings ponds and old environmental loads were applied and their metabolic activity contributes to the biodegradation and biosolubilization of metals. The most efficient recovery of rubidium and caesium was achieved using consortia composed of heterotrophic microscopic fungi and yeasts, which achieved up to 11.8% average efficiency in the release of rubidium into the leaching solution and up to 14.21% bioaccumulation of the metal into their biomass. For caesium, the highest average efficiency of 4.92% metal leaching and 10.33% metal bioaccumulation in fungal biomass was achieved. The bioleaching experiments also showed high biovolatility of both metals, which reached up to 57.8% and 85.95% for rubidium and caesium, respectively. Considering the increasing demand for alkali metals, which is closely related to their use in the technologies of the modern world, taking into account the low initial investment costs and also the demonstrated high potential of microorganisms to bioextract rubidium and caesium from secondary and waste raw materials, the heterotrophic leaching process can be considered very promising for introduction into modern biotechnological practice.