Doctoral student Karolina Sobieraj: – The UPWr Doctoral School was meant for me

– I like to think of my studies at the university as my destiny. During the recruitment process for my engineering studies, I travelled to Wrocław from my hometown with two sets of documents – one for the Renewable Energy Sources and Waste Management course at the UPWr and for another course, related to the humanities. It was during this trip that I decided to choose my current studies, and my initial uncertainty turned into my love for science today.

Karolina's doctoral dissertation topic is "Biological production of carbon monoxide from biowaste". She is working on it as part of the POWER 3.5 UPWr 2.0 program - an international and interdisciplinary development program of the University of Environmental and Life Sciences in Wrocław, under the lead of two supervisors – Prof. Andrzej Białowiec from the Department of Applied Bioeconomy of the UPWr and Prof. Jacek Koziel from Iowa State University in the United States. – My cooperation with Prof. Białowiec started during my undergraduate studies. Things started to change when we published our first joint scientific article – says Karolina Sobieraj, emphasising that from the very beginning he had provided her with great support in the scientific world, and as a supervisor and mentor had motivated her to face new challenges, such as cooperation with industry, participation in research and development projects or international scientific conferences. It was also Professor Białowiec who had persuaded her to apply for a scholarship from the Minister of Science and Higher Education for students with outstanding scientific achievements, which she received.

– My second supervisor, Prof. Koziel, also helped me immensely, especially with the preparation of joint scientific articles, and was also a great inspiration, providing a fresh approach and motivation to aim high – says the doctoral student, adding that when she got the chance to participate in the POWER 3.5 program, which requires cooperation with a supervisor from an external unit, her choice was obvious.

In her research, Karolina wants to investigate how the technological parameters of the bio-waste composting process, such as temperature, oxygen saturation, the content of organic matter in the waste and its humidity, affect the amount of carbon monoxide produced during this process.

– My task is to prepare a theoretical concept related to the possibility of controlling CO production from the composting process by developing a mathematical model for the intensification of production. Despite its harmful impact on the natural environment and living organisms, CO has numerous functional properties that are used in many branches of the economy. The focus on increasing CO production from waste composting, which is the direction I would like to take in my research, is actually innovative and has not been described in written form so far – explains Karolina.

During her work at the Doctoral School, Karolina Sobieraj would like to check whether the composting process can be a potential source of CO, which, extracted from the process gas, could be used as a component of biosyngas, i.e. synthesis gas generated from biomass. This biosyngas could then be used, among others, as fuel or the basis for the production of ethanol and methanol at a competitive price, and its conversion could lead to the production of hydrocarbons and aromatics.

– Syngas conversion as a result of the Fischer-Tropsch reaction can lead to the production of transport biofuel, and the vapour conversion of CO known as the water-gas shift reaction (WGS) is a source of hydrogen. However, we would need to identify the optimal parameters of the composting process so that CO production can be controlled – says Karolina.

Additionally, as part of the work started on the series of publications included in the future doctoral dissertation, together with the co-authors, Karolina prepared a review publication on CO changes during the decomposition of organic matter. In this way she gathered information on innovative and future directions of carbon monoxide utilisation, based on its production and processing in a biological way using the activity of microorganisms capable of metabolising it. However, she was mostly interested in the biological version of the WGS method, which uses bacteria capable of producing enzymes: carbon monoxide dehydrogenase (CODH) and hydrogenase.

– The biological WGS reaction replaces the previous one, carried out with the use of inorganic catalysts. The conditions for the process are less demanding, which makes it more competitive – it takes place at ambient temperature and pressure, and in the dark, which reduces the cost of the necessary reactors. The prospect of using a supposedly harmful gas produced during composting for industrial purposes seems promising and would make this method of waste processing considerably more attractive – Karolina Sobieraj stresses, adding that the composting process has great potential. The changing size of the population of the Earth and the growing standard of living mean that the amount of generated waste is constantly growing. Its global weight is estimated to increase to 3.4 billion tonnes in 2050, and bio-waste has the largest share in municipal waste in low and middle-income countries. In addition, there has been a noticeable increase in the amount of waste from intensive agricultural production, as well as the global problem of food waste. This broad spectrum of waste is therefore a potential compostable material, especially that this type of treatment is dominant in Europe and deals with over 60% of produced bio-waste.

Karolina became interested in the subject of the production of gases from the processing of organic waste during her master's studies. At the time she was checking their spatial distribution inside material on a compost pile.

– I was using equipment that let me measure, among others, CO concentration. However, I did not expect it to be present, as it is usually associated with combustion processes. So I was all the more surprised when this gas not only appeared in composted organic waste, but its concentration exceeded several hundred ppm – says the doctoral student, stressing that it was due to the unpredictable production of the gas – both in aerobic and anaerobic areas of the compost pile, as well as at high and low temperatures – that she decided to transfer the research to a laboratory to learn about the basic mechanisms of CO formation and, together with her supervisors, came up with the research she is currently conducting at the UPWr Doctoral School.

Karolina Sobieraj, as a member of a Leading Research Group, is also a contractor in three research projects, financed, among others, by the National Centre for Research and Development and the Ministry of Science and Higher Education. Working together with her teammates, she covers a wide range of scientific disciplines. In addition to developing innovative waste-based organic fertilisers, evaluating their use in the cultivation of selected spices, and analysing the combination of biological and thermochemical treatment of bio-waste to increase the efficiency of the process and minimise its environmental impact, Karolina Sobieraj will also participate in the research of Dr. Jacek Łyczko on new generation appetite-regulating substances. In this project, the doctoral student will be responsible for the analysis of the morphological composition of food waste of studied patients. In other words, she will check whether their eating habits have changed and are permanent after using the developed appetite-regulating substances.

Currently, having received a positive result in her mid-term evaluation, Karolina Sobieraj is halfway through her work at the Doctoral School. Her next two years of study will certainly be busy, full of research projects and foreign internships, including at Iowa State University under the supervision of Prof. Jacek Koziel and the Fudan University in Shanghai as part of the team of Prof. Shicheng Zhang. The doctoral student also hopes she will have a chance to work on a project received under the Preludium 20 grant, in which her application has just passed to the second, and last, stage of substantive assessment. However, she still wants to look for new areas for her scientific research. – I think that as a society we have reached a point where the discipline I work in – environmental engineering – is no longer just a way to solve the problems we have caused by our actions, but an area where fast and continuous development is necessary – Karolina Sobieraj emphasises.