Conversation with prof. dr hab. Ewa Maria Siedlecka
Faculty of Chemistry, Department of General and Inorganic Chemistry
Professor, considering your research interests and scientific achievements, please tell us how you understand sustainable development.
To leave such resources so that future generations can use clean water and air, enjoy green places, and listen to birds singing. From the perspective of my discipline, which is chemistry, and I deal with sewage and water treatment, I can see how the imbalance in the use of the environment and the lack of understanding of the complexity of its functioning negatively affects its quality, and our attempts to repair the negative effects of our actions are not always successful. We – as a society – think we have enough water. When I talk to students and ask whether Poland is one of the countries where there may be a water shortage, they are sometimes surprised that such a problem can arise. In the 1990s, there was a discussion about the significant content of nutrients in water and students know about this problem, but when we move on to today’s challenges, we discuss medicines that are consumed in very large quantities and then discharged with treated urban sewage into the water. This topic isn’t always known to students. The latest research indicates that psychotropic substances also occur in water at the detection level of currently used analytical methods. They pose a danger because over time these substances can get into drinking water. Yet another problem is microplastics. I cooperate with the Pomeranian District of the Polish Ecological Club, where we run projects on monitoring microplastics in the Pomeranian Voivodeship. The research results were presented in the European Parliament, where we were invited along with other speakers to discuss the state of the environment. In our speech, we focused mainly on the Baltic Sea and its tributaries. The research shows that microplastics are present in surface waters that flow into the Baltic Sea, with the Motława River being the most polluted. In the waters, we found mainly microfibers coming from shipping and the use of plastic textiles. German research shows that microfibers from fabrics constitute almost 30% or perhaps even more of the total amount of microplastics introduced into the environment. They are created when washing clothes made of such materials.
The research of my scientific group concerns the search for effective methods of removing micropollutants, especially pharmaceuticals, from water, which should be considered not only a scientific problem but also an application one. We have a European Union directive obliging us to remove micropollutants from wastewater, but the problem is to find an economically viable and effective method of removing them on an industrial scale. The level of micropollutants, including medicines, discharged together with treated sewage is significant. Our treatment plants haven’t been designed to remove this type of difficult-to-biodegrade pollutants and, like other treatment plants in Europe, they are based mainly on mechanical and biological treatment processes.
My research group deals with methods of drug neutralisation, i.e., removing both native compounds and products that are produced during their metabolism in our bodies. Metabolites are usually not analysed at the inlet of the treatment plant, but it’s known that they can be dangerous due to their potential biological activity as well as native forms. We develop advanced oxidation methods for their effective removal. In the first stage, we design and synthesise materials that support the oxidation and mineralisation of these compounds in the presence of sunlight. Then, we optimise the conditions for conducting such processes and check whether the treated sewage or water isn’t ecotoxic, i.e., whether it’s safe for the environment. We also deal with processes of producing alternative fuels from renewable energy sources, but so far these methods have been mainly used in the laboratory. We also participate in fieldwork. We participated in a project in a pilot station in which pharmaceuticals were removed by means of the ozonation and adsorption processes on activated carbon. The research was conducted at a full-scale urban sewage treatment plant. In real conditions, we analysed and optimised the operating parameters of this facility. This is the first such station in Poland. There are similar facilities in Sweden, and Switzerland has also developed methods of removing micropollutants by means of the ozonation process. There is great interest in this issue. We are aware that without the introduction of the stage of removing micropollutants from wastewater, the concentration of medicines in the environment will increase. The presence of medicines in the environment results in medicine resistance in bacteria. If we don’t reduce the introduction of medicines into water, we may have to develop new types of antibiotics, because the ones that currently work will no longer be effective.
Professor, how do sewage treatment plants operate on a large scale today in terms of purifying wastewater from pharmaceuticals and microfibers? You are talking about pilots, but what does it look like on a large scale? Are we coping with this? We know that there is basically no monitoring in the world.
Monitoring is carried out selectively. Many research groups in France, England and Poland monitor pollutants that are of interest to them. Many scientific works have been written that deal with this problem in terms of medicines, microplastics and narcotics. Reports from sewage treatment plants in Kraków (Płaszów and Kujawy) indicate the presence of significant amounts of medicines such as diclofenac, carbamazepine, sulfamethoxazole, which can be found in every European sewage treatment plant. We can say that the medicine removal efficiency in European wastewater treatment plants is similar. Treated sewage discharged into the environment contains antibiotics, hormonal drugs, antidepressants, painkillers, and antihypertensive drugs. Their amounts in sewage depend on their availability and consumption in each country. Research has shown that in Sweden and Poland, the concentrations of medicines in sewage are similar, but treated urban sewage differs, for example, in terms of the content of organic matter. Therefore, the introduction of new technology requires its optimisation for the specific conditions of a given catchment.
If we don’t reduce the introduction of medicines into water, we may have to develop new types of antibiotics, because the ones that currently work will no longer be effective.
Coming back to your question, sewage treatment plants remove medicines to varying degrees, which results from their chemical structure and susceptibility to degradation by microorganisms. Hormonal compounds, such as oestrogens, are almost completely removed from sewage. But when discharged into rivers and waters, the small amount that is released is enough to negatively affect living organisms. Therefore, it’s important whether the concentration of medicines introduced into waters has a negative impact on living organisms, because if we have medicines that are present in a concentration lower than the concentration that causes a negative effect, we approach these types of compounds differently. In the case of non-steroidal anti-inflammatory drugs or antibiotics, the removal efficiency, depending on the type of medicine, ranges from 80 to 20%. In turn, some medicines, e.g., carbamazepine or diclofenac, may have higher concentrations at the outlet from the sewage treatment plant than at the inlet.
What does it mean?
Medicines are metabolised in our body and the products that emerge can be transformed into native compounds during biological wastewater treatment. This means that at the inlet we are dealing with a mixture of the medicine and its metabolites, which are decomposed during wastewater treatment and the initial medicine is recreated. When examining only the native form of the medicine, we don’t see any metabolites at the inlet, but we do observe an increase in the concentration of the native form at the outlet. It should be added that even if the medicine is effectively removed during sewage treatment using a mechanical-biological method, it may accumulate to a significant extent in sediments. We treat sewage by means of the so-called activated sludge method, i.e., using microorganisms that live in a floc. The adsorption process may take place on this floc. Then, the sludge should be stabilised in such a way as to neutralise the medicines. This means that we are shifting the problem from water and sewage to stabilisation and utilisation of sludge.
We have a very similar problem with microplastics, of which we remove more than 90%. This means that we achieve a good result, but these substances are still present in the sediments in the unchanged form. As I mentioned earlier, we subject sediments to stabilisation processes. Some sewage treatment plants try to use stabilised sludge, e.g., for soil reclamation. This leads to the secondary introduction of microplastics into the environment. It’s worth noting that monitoring microplastics in water is incomparably easier from an analytical point of view than monitoring microplastics in sediments. We have some data on water, but when it comes to sediments, there is much less of it, but the data that we have clearly show that microplastics from sewage accumulate in sediments.
Is this a progressive process, or can we see some improvement now, both in the case of medicines and microplastics?
The consumption of medicines and plastics, especially disposable ones, is still high. However, it should be noted that we are at a stage of civilisation development where, thanks to medicine, we live longer. We are a society that uses over-the-counter drugs relatively willingly. This applies not only to Poles. Statistical data show that residents of many European countries consume significant amounts of medicines. Among many other reasons is the desire to live without pain or to feel young. Let’s also remember that the number of people in the world is increasing, so the global consumption of medicines will grow. I think that doctors play a very important role here, as they have a significant impact on what and in what quantities we consume. When it comes to monitoring, we can’t monitor all medicines, we must select those that will be indicators for us to objectively assess the situation. The next step should be the introduction of legal acts that will set the direction for assessing the effectiveness of micropollutants removal and their control. The micropollutants we are concerned about include not only medicines but also phthalates and bisphenol A. We know that some phthalates have a very negative impact on reproduction, so they should be monitored. We still have a long way to go, but we can see some progress, we are introducing monitoring of selected substances, we are looking for effective methods of removing micropollutants such as advanced oxidation, and we are testing pilot stations using ozonation and adsorption on carbon. Moreover, in the case of disposable items made of plastics, we have tried to replace them with other more environmentally friendly materials since 2021.
Thank you very much for such a comprehensive answer. What actions connected with the sustainable development goals should be taken at the University of Gdańsk?
The sustainable development goals are very broad, they concern both society, economic development, and the economy. I will refer to social issues. When I observe young people, it seems to me that many of them are eager to get involved in broadly understood planetary issues. I’m fascinated with the idea of sharing. I know that there are special refrigerators where you can share food if you buy or cook too much. Places where things made from waste are sold are also good, as they give them a second life. I think this is a space for our students’ creativity and ingenuity. It doesn’t have to be a shop as such, but a place where you can share different ideas and help repair broken things. You can also exchange or borrow various devices or things that you’ve bought or received and used several times. We often throw away such new items which are in good condition or keep them in the basement for many years. Such a place would allow others to use these unwanted items and at the same time reduce the amount of generated waste. Artistically gifted people could exhibit their works made of waste in such a place. This place would have an educational dimension and make people aware that the life of so many items we throw away can be extended. The place I am talking about would promote good waste management practices and teach economics. I know that our students are very creative. They are willing to engage in work that requires them to be creative. Then they are more motivated to work and can surprise us, teachers. I think they might like this idea. Moreover, as academic teachers, we should set a good example when it comes to pro-ecological behaviour. Just talking about it isn’t enough. We segregate waste on campus. In laboratories, we teach students how to deal with hazardous waste. I think it’s worth encouraging people to come by bike, to save electricity and water, that is, to make certain ecological behaviours fashionable and promote them. People are more willing to take on certain tasks if they are trendy. Then it’s easier to put effort into completing such a task. Above all, we should clearly show students through our behaviour that unecological attitudes are passé, and at the University of Gdańsk, we promote all ways of being that are consistent with the principles of sustainable development.
The next question concerns students and raising their awareness in attaining the sustainable development goals. You’ve talked about good practices. What else could be important?
I think we have a lot of activities, including lectures and seminars, that are related to sustainable development. I tell students about green technologies and what proper waste and sewage management looks like. However, I notice that students show little interest if ecology is only talked about. It’s important to engage students in activities in which they look for solutions. I was recently very pleased with a class in which students attempted to evaluate car journeys using petrol, gas, and electricity. We compared costs, time, and the possibility of refuelling during such a trip. The students were very well prepared. We discussed many economic and ecological issues regarding sustainable development. They came to certain conclusions themselves by looking at the numbers. The conclusion of our discussion was that an electric car is ecological, but only on the condition that in Poland greater emphasis is placed on energy from renewable sources. I think it’s worth taking an innovative approach to transferring knowledge. I see an opportunity here for student projects, discussions and exhibitions that would raise awareness of threats and challenges. We live in a beautiful place on the Baltic Sea coast, and our knowledge as a society about the quality of its waters and threats isn’t very extensive. At the Faculty of Chemistry where I work, we try to combine chemical knowledge of e.g., acid-base equilibria or colloidal solutions with ecological knowledge, so that our students can translate this basic knowledge into practice. Students need to realise that these aren’t just processes discussed during chemistry classes. Since chemical knowledge, we try to understand nature, how it works, and how it defends itself against the pollutants we introduce into it. Nature is a very complex system and interference in one of its elements results in a whole series of subsequent events. We see this at every step, as well as during every ecological disaster that affects us, e.g., the fish kills in the Odra River. I think that making the entire society aware of these relationships on various occasions, e.g., events organised for schools or residents of Gdańsk, is very important, and our students should also play the role of educators.
I must ask about our campus and nature. How do you see this issue, what should we do to make the campus more open and show that at the University of Gdańsk we want to achieve the sustainable development goals and work towards them? What could we do as a university, in your opinion?
We have a beautiful park, which is located between the Faculties of Biology, Chemistry, Mathematics and Computer Science, but there is no life in there. Of course, the pandemic significantly cooled down the life of the academic community, but it should now return to the faculties and the park. I think it’s a great place for student life and events related not only to the academic community. I’m pleased with all the events that we held last academic year. We can see a revival on campus, the organisation of picnics, which means we are slowly returning to normal functioning as a community. Such meetings are very important because they give us a sense of community.
Professor, what main barriers and challenges do you notice in connection with the implementation of the 2030 Agenda?
We often say that we want to act ecologically, but our habits don’t allow us to move from talking to action. We need to work on our mentality to go beyond declarations and follow the principles of sustainable development. I think that these habits are better ingrained in young people because they’ve heard about the threats and ways to reduce them since childhood. For many years, we have become accustomed to disposable items. We heard use it and throw it away, no one worried about the amount of waste generated this way. Currently, we are aware of how much plastic waste remains in the environment. We are looking for technologies for their disposal or management. However, it’s difficult for us to part with plastic water bottles or shopping bags. We have become accustomed to the convenience of plastic packaging. I hope that the current generations of children and young people will abandon these disastrous habits and based on knowledge and their own experiences, will conclude that consumption shouldn’t be excessive, but rather should be well-thought-out. Young people pay attention to what they buy. In many situations, students show that they are conscious consumers and know producers’ tricks, e.g., regarding the excessive size of a product packaging, to visually convince us that there is more of it in the package. Young people check the chemical composition of cosmetics, avoid products containing microplastics, check food additives and avoid products that contain too much of them or are known to be harmful. I hope that there will be more and more people who will support natural food and products that don’t negatively impact the environment at any stage of their life cycle.
This also shows how important interdisciplinary research is.
It can be said that interdisciplinarity is a feature of the modern way of doing science. Interdisciplinary research enables solving complex problems, such as those occurring in environmental protection, to understand them better. The research conducted by my group can be considered interdisciplinary. First, we design and synthesise new semiconductor materials. We assess their properties through a series of physicochemical tests. We use these materials to develop methods for removing medicines or producing alternative fuels, e.g., hydrogen. We analyse whether the method we’ve developed and the sewage or water it treats are safe for the environment. We compare the results of our experiments with theoretical calculations, which at certain stages of research allow us to make decisions in which direction we’ll go next. If the research results are promising, we can move on to research on a larger scale than in the laboratory. To carry out this planned scope of research, we use the help of physicists, biologists, and process engineers.
We have become accustomed to the convenience of plastic packaging. I hope that the current generations of children and young people will abandon these disastrous habits and based on knowledge and their own experiences, will conclude that consumption shouldn’t be excessive, but rather should be well-thought-out.
This is still research within the natural and exact sciences, and it would probably be good to combine it all with the social sciences and even the humanities, I think that it would also be good to move in this direction and implement this type of projects and, hopefully, that it will be possible at our university and we’ll work and network in this way and apply these solutions somewhere.
In my opinion, combining aspects of social sciences and humanities with exact science is extremely important. Indeed, previously we confined ourselves to our discipline when carrying out our activities. Nowadays, our reality is different, and many projects focus on combining different disciplines. Social sciences can be helpful in assessing the usefulness of our research or in finding areas in which the solutions we develop can be used. Thanks to them, we can also learn about social needs, which will indicate what problems we should address. Economics can help us in getting businesses interested in our research.
Discussions with economists, process engineers, the economic environment, or representatives of the humanities allow us to see the directions and possibilities of using our research in a broader sense. Interdisciplinarity is important because each of us has a different perspective on the same problem, and by working together we become more creative. You could say that we encourage each other to develop. I was lucky to cooperate with people from the Faculty of Social Sciences in the field of waste and energy management. I know that their approach to the topic is different, which makes us complement each other. Thanks to this, our power to act and present externally what we can do and what we can offer to the socio-economic environment is greater, and together our chances for success will increase.
Interview by dr Irena Chawrilska.