BIO BAUX project – Envirotox

Bauxite residue (red mud) is the waste of alumina production from bauxite by the Bayer process (hot digestion with caustic soda). An estimated 4.4 billion tonnes of BR have been deposited worldwide by 2018, and approx. 50 million tonnes are stored in Hungary. In recent years the recovery of economically important elements, such as Sc, Ga, Ti, V and rare earth elements (REEs), has gained interest due to the increasing demand for critical raw materials (CRMs) in Europe with increasing supply risk. These elements are essential for the high-tech and low-carbon industries (e.g. LEDs, smartphones, windmills, electric cars) for our modern lives. Bauxite residue is an ideal resource for CRMs, however, we need green (e.g. low energy intensive) technologies to recover CRMs. Biotechnological approaches 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, such as low-grade ores. This project aims to understand the mechanisms of bioleaching processes for the leaching of targeted CRMs by fungi and bacteria from bauxite residue. We will also investigate the microbial composition of bauxite residues from Hungary and Europe and isolate microbial strains with potential biotechnological applications. We will assess the characteristics of the leaching residue and its reusability. The results may contribute to the supply of Hungary and Europe’s CRM demand and the development of bio-based bauxite residue processing technologies.

Funding: National Research and Innovation Office, OTKA FK 146542: Mechanisms of critical raw materials bioleaching from bauxite residue project

Project leader: Dr. Viktória Feigl

Duration: 01.01.2024-31.012.2027.

Informative presentation at BME Open Day
- Anna Brigitta Budai: Bioleaching of critical raw materials from Greek red mud, TDK presentation, BME Open Day, Students’ Point of View on Research, November 29, 2025
Scientific Student Conference thesis
- Anna Brigitta Budai: Bioleaching of critical raw materials from Greek red mud, BME VBK ABÉT, 2025, Supervisor: Dr Viktória Feigl, BME Scientific Student Conference, Faculty of Chemical Engineering and Bioengineering, Biochemistry, Biotechnology and Food Science Section, 2nd place, and Inter-University Sustainability Section, Pro Progressio 3rd place, 19 November 2025
Project presentation conference lecture
- Viktória Feigl: Sustainability in bioengineering education at BME, The integration of protection of creation/sustainability into education conference, November 14-15, 2025, Eszterházy Károly Catholic University, Eger
Project presentation
- Viktória Feigl: Biotechnologies for the environment, BME Innovation Day and Competence Fair – “BME – on New Paths of Innovation”, June 26, 2025, Budapest University of Technology and Economics, Budapest
Three BSc theses
- Anna Brigitta Budai: Bioleaching of critical raw materials from Greek red mud, BME VBK ABÉT, 2025, Supervisor: Dr Viktória Feigl
- Botond Vankó: Extraction of valuable elements from red mud using bioleaching, with economic prospects, BME GTK KFFT, 2025, Supervisors: Beszedics-Jäger Bettina Szimonetta, Dr Viktória Feigl
- Jázmin Anna Komjáti: Cultivation of Aspergillus strains on waste-based media for the biological leaching of critical raw materials from red mud, BME VBK ABÉT, 2025, Supervisor: Dr Viktória Feigl
National Scientific Student Conference thesis
- Melinda Zsuzsanna Röhberg: Potential biotechnological utilization of microorganisms isolated from red mud, BME VBK ABÉT, 2025, Supervisor: Dr Viktória Feigl, National Scientific Student Conference Agricultural Science Section, Environmental Science Division, Sapientia Hungarian University of Transylvania, Miercurea Ciuc, commendation, 24-26 April, 2025.
Conference presentation
- Viktória Feigl, Melinda Zsuzsanna Röhberg, Kinga Masa, Henrik Hegedűs, Zsuzsanna Janek, Veronika Deák, Anna Medgyes-Horváth: Isolation of extremophile microorganisms from red mud and their potential biotechnological utilization, Technical Chemistry Days ’25, 15-17 April, 2025, Pannon University, Veszprém

Dissemination activities in the first year of the project:

Four BSc theses
- Henrik Hegedűs: Searching for extremophilic fungal species in red mud and exploring their potential biotechnological applications, BME VBK ABÉT, 2024, Supervisor: Dr Viktória Feigl
- Kinga Masa: Characterisation of bacteria isolated from red mud, BME VBK ABÉT, 2024, Supervisor: Dr Viktória Feigl
- Dóra Mukics: Bioleaching of critical raw materials from red mud with Aspergillus species, BME VBK ABÉT, 2024, Supervisor: Dr Viktória Feigl
- Melinda Zsuzsanna Röhberg: Potential biotechnological application of microorganisms isolated from red mud, BME VBK ABÉT, 2024, Supervisor: Dr Viktória Feigl
Scientific Student Conference thesis
- Melinda Zsuzsanna Röhberg: Potential biotechnological application of microorganisms isolated from red mud, BME VBK ABÉT, 2024, Supervisor: Dr Viktória Feig, BME Scientific Student Conference, Technical Sustainability Section, 2nd place, 21.11.2024.
Informative lecture and discussion at BME
- Critical raw materials from waste: the potential for reuse of bauxite residue , 20.11.2024. 16:00, BME F. building Schay room
  Presenters: Prof János Szépvölgyi, HUN-REN TTK, Dr Viktória Feigl, BME VBK ABÉT
Dissemination of knowledge at the Researchers’ Night
- Hello, can you be seen under the microscope? – I even glow in the dark!– Laboratory demonstration program by the Research Group of Environmental Microbiology and Biotechnology presenting fungi able to extract critical raw materials from bauxite residue, 27.09.2024.
Conference lecture
- Viktória Feigl, Dóra Mukics, Botond Vankó, Zsuzsanna Janek, József Dorogi: Bioleaching of critical raw materials from Hungarian bauxite residue, CEMEPE/SECOTOX Conference, 16-20.06.2024., Lefkada, Greece

Successful thesis defense

National Scientific Student Conference

Technical Chemistry Days ’25