The currently announced doctoral topics are available on the National Doctoral Council’s website: doktori.hu.
Please send an e-mail with a brief introduction (qualification, field of study, specialisation, previous research activities), CV and motivation letter to the professor of your choice.
Topic 1. Bioleaching of critical raw materials from bauxite residue
Description: Bauxite residue (red mud) is the waste of alumina production from bauxite by the Bayer process. It is an ideal resource for economically important elements, such as Sc, Ga, Ti, V and rare earth elements (REEs), due to the increasing demand for critical raw materials (CRMs) in Europe with increasing supply risk. Biotechnological approaches for CRM recovery show advantages compared to pyro- and hydrometallurgical processes, e.g., lower temperatures, less chemical consumption, and lower costs. Bioleaching (biomining) applies microorganisms to solubilise metals from hardly soluble substrates. This PhD project aims to understand the mechanisms of bioleaching processes for the leaching of targeted CRMs by fungi and bacteria from various European bauxite residues. The PhD candidate will examine the effect of microbial media composition, BR pulp density, contact time, temperature, and shaking on bioleaching and the potential for selective leaching of elements. They will also assess the characteristics of the leaching residue and its reusability. Environmental and economic aspects of the novel biotechnological approach will be investigated. The ideal candidate knows the fields of biotechnology, microbiology and environmental chemistry. The results will contribute to the potential application of bioleaching as a green, bio-based technology for CRM extraction from bauxite residues.
Supervisor: Dr. Viktória Feigl, feigl.viktoria@vbk.bme.hu
Topic 2. Ecotoxicity assessment of the effect of graphene oxide nanoparticles and coexisting micropollutants through a multimarker approach at individual and community levels
Description: It has been demonstrated that carbon-based nanomaterials, such as graphene oxide (GO) may have a variety of effects on aquatic organisms at different trophic levels, however we are at the beginning of understanding the behaviour of these unique materials and their effect in the environment.
The main objective of the PhD research – in line with current research directions – to fill in the critical knowledge gaps by comprehensively assess the effect of GO and its derivatives at environmentally relevant concentrations in acute and chronic single species ecotoxicity tests as well as in complex microcosm experiments under more environmentally relevant circumstances. In various biological test systems e.g. Chlorella vulgaris, Daphnia magna and Heterocypris incongruens bioassays, a multimarker-approach will be applied. Standard and innovative ecotoxicological endpoints will be applied at molecular, physiological and behavioural levels combined with thorough physico-chemical characterization of the original GO derivatives suspensions as well as determination of their concentration- and time-dependent aggregation characteristics and stability in the applied test media. At each level of ecological complexity the combined effect of GO derivatives with the coexisting biologically active micropollutants e.g. triclosan will be investigated. The research also contains the investigation of the antioxidative processes in D. magna. By determining oxidative stress enzymatic biomarkers and ROS generation this research addresses important questions of the underlying toxicity mechanisms. The ecotoxicological data obtained during the PhD project will be comparatively evaluated with the aggregation state and surface-chemistry characteristics of GO derivatives in the applied test systems to reveal the underlying toxicity mechanisms and biologically important characteristics of GO derivatives. The planned, tiered experiments of impact assessment allows a more environmentally relevant risk assessment of GO derivatives highlighting the use of environmentally relevant concentrations and conditions providing a unique possibility to gain reliable data on the effect of GO derivatives on the aquatic ecosystem.
Supervisor: Dr. Ildikó Fekete-Kertész, fekete.kertesz.ildiko@vbk.bme.hu
Please ask the professors for actual topics!
Dr. Mónika Molnár: molnar.monika@vbk.bme.hu
Dr. Viktoria Feigl: feigl.viktoria@vbk.bme.hu
Dr. Ildiko Fekete-Kertész: fekete.kertesz.ildiko@vbk.bme.hu