During the anaerobic fermentation of organic residual streams, the core process in the production of biogas, sulfur-based compounds are often co-products. The presence of hydrogen sulfide (H2S) in the gas is problematic due to its toxicity and corrosive properties. Therefore, some desulfurization strategies were developed to efficiently remove such compound from the biogas mixture.

One strategy often implemented is the catalytic oxidation of the H2S into elemental sulfur (S0). This allows a clean separation resulting into a recovered stream of solid sulfur that can be further valorized into other products, such as sulfuric acid (H2SO4), which is a useful material to be used within the biogas facility itself. Many processes can be applied in this conversion, including a biological pathway where the organism Acidithiobacillus thiooxidans promotes the oxidation of S0 in parallel with the fixation of carbon dioxide (CO2). This strategy has the potential to largely increase the circularity of this overall process

In this project, the biological production of H2SO4 will be assessed and optimized under controlled laboratory conditions. The fermentation experiments will first take place on shake flasks of different sizes, where different growth media will be tested. Different process parameters will be analyzed and compared, such as pH, sulfur concentration and particle size, aeration, and sterility of the material. The most promising conditions will be evaluated on bioreactors for the highest productivity of H2SO4.

Analytical methods consist of spectrophotometry for microbial growth, and the development of an adequate protocol for measurements of produced H2SO4 through turbidity (spectrophotometry).

If you have experience with fermentation and has an open and curious mind, you are in the right place. HBO students with a suitable background are welcome to apply.


February 2024 – July 2024

Who we are:

You will be working for the research group Biobased Resources & Energy within the center of expertise MNEXT – Material and Energy Transition. MNEXT is powered by the Avans and HZ Universities of Applied Sciences and helps businesses achieve their biobased goals by working with them to modernize higher professional education and to carry out applied research that makes a difference. The Biobased Resource & Energy research group is focused on valorizing residual streams from nature, agriculture or industrial sources, and the production and use of biobased energy.

More information:

Feel free to contact Guilherme de Souza Reisga.desouzareis@avans.nl


The intern will be provided with a monthly payment of €350.


Send an application with CV and motivation to ga.desouzareis@avans.nl


Bij het gebruik van deze website gaat u akkoord met het gebruik van cookies. Meer informatie

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.