Behind the PhD degree: Olga Sójka

Technology is a direct tool to tackle some of our world’s problems, according to PhD candidate Olga Sójka. And wouldn’t it be nice if everyone had it nice – is her philosophy. So, she dedicated a part of her life to finding these solutions. Having finished her research on preventing bacterial growth in essential drinking water distribution systems, she is proud that she could make a difference and is still happy to do more.

The people behind the science, and the science behind the people

A productive way to make a change

With empathy as a core talent, Olga has always felt a need to make a difference for others. It was her drive to do a degree in Environmental Protection Engineering, covering a wide range of topics from water through soil to solid waste management. But it’s water that spoke to her most. ” The versatility of water technologies struck me, and I found that the Water Technology master at Wetsus was the perfect match,” the young researcher decided.

“It was a great experience, my first working in the international environment. Here in the Netherlands, you are much more focused on innovation as opposed to conservative practicality in Poland. At the Water Technology master, we had a chance to visit multiple facilities, which showed us that innovative technologies can provide solutions beyond wastewater treatment. We learnt that wastewater is not waste, but a source of valuable resources. At Wetsus, they see this and they focus on providing tools to make a change.”

After her graduation, she has worked as a water technologist first. But it wasn’t for her. Olga: “While working in the industry, I struggled with the profit-driven approach, which often rushed the delivery of solutions without a proper investigation. I was missing the depth which made me think of returning to research. ” Back to Wetsus, it was.

Nanogel coatings

The persistent researcher eventually found herself in the Biofilms theme. Her goal: to translate the biomedical experience in preventing biofilms to developing bacteria-repelling layers applicable in drinking water distribution systems. These coatings are now used in medical implants, for instance.

“Hydrogels are soft swelling materials that hold water. In theory, bacteria prefer to stick to hydrophobic – water-repelling – layers. Otherwise, they have to move water molecules on a surface aside, which costs a lot of energy,” Olga explains. The hydrogels retain a layer of water, fooling the bacteria.

“We started using the macroscopic hydrogel coatings but discovered they could only be applied to soft rubber surfaces. So, it could providea good strategy to target microbial attachment to rubber-based elements, likerubber-coated valves, but we wanted to look for a universal solution to prevent – or at least delay biofilm development. As an alternative, we selected nanogel-based coatings. Not only they offer all the advantages of hydrogels, but also their form of spherical nanosized particles makes them easily applicable as a coating.”

But of course, there are multiple challenges when translating the technology from one distinct field to another. Olga: “Drinking water bacteria are quite different from clinical strains. For instance, common organism used for testing the anti-adhesive coatings is a small round bacterium Staphylococcus aureus. To attach to the surface it depends on an uncoated site big enough to support its whole body. In drinking water, we have many more bacteria with a tail – a flagellum – that can attach to small imperfections in a coating as it is much thinner than a bacterium itself.”

Moreover, unlike in medical cases, these coating should withstand the critters  long term. “Drinking water pipes are installed for decades. Therefore, the coatings should remain stable and effective for extended periods of time. So, we performed a variety of tests lasting from 24 hours up to five weeks.”


And it worked. Depending on the bacteria tested, the nanogel layers repelled between 80 to 99% of the bugs. A unique feat with the mix of organisms never used for such test before. Olga: “It may take a long time before such coatings will be introduced to the drinking water sector, but we showed it that they are resilient against biofilms in representative circumstances. The goal of such application is to target water distribution sections that are the most prone to biofilm development – like in places of low flow or dead ends. And such coatings offer a great potential for small scale applications, such as drinking water end points like taps, hoses used in gardens or for cleaning industrial facilities, too. Nanogel coatings can ensure the safety of drinking water.”

The project is continued by another PhD candidate who focuses on long-term testing, and Olga now helps with its supervision as a part of her post-doc position. “At some point I had doubts if I will be able to finish this PhD, but I am proud I will. I hope to continue my work in a similar environment as here at Wetsus where industry meets research to respond to the increasing challenges we are and will be facing due to the climate change.”

Towards an economy of value preservation | By Niels Faber


The realisation of a circular economy has thus far unfolded under the assumption that it would fit within existing economic arrangements. In practice, we witness many circular initiatives struggling to give shape to their ambitions, let alone develop to maturity. These past months, various material recycling organisations terminated their activities, seeing virgin alternatives from other parts of the world flooding the market at prices against they cannot compete. If the transition towards a circular economy (i.e. an economy of value preservation) is to be taken seriously, a new perspective on value in our economic system seems unavoidable, as the rewriting of the rules of the economic game. At this moment, current perceptions of value stand in the way of this transition both at micro as well as macro levels. Several contours for a collective exploration of new directions of value and economic configuration that foster circular transition will be addressed.

Searching Innovation for the Common Good | By Cees Buisman


In his key note he will conclude after a life of innovations that it is impossible that humanity will stay within the save planetary boundaries with innovation only. We should be more critical about the behaviour of the rich population in the world and more critical about new innovations that prove to be dangerous, like the PFAS crisis shows at this moment. In his keynote he will investigate how to look at the world that can stay within the save planetary boundaries, how should we change ourselves? It is clear if we only talk about the words of science and systems we miss the essential words of how we should cooperate and change ourselves. And his search for coherent save innovations. Which innovations will be save and will lead to a fair and sustainable world? And will lead to a world we want to live in.

Future-fit economic models: What do they have in common – how can they join forces? | By Christian Felber


There is a growing number of new sustainable, inclusive, cohesive, participatory, just and humane economic models. A possible next step in the discourse about them is the comparative analysis in order to find out key commonalities, potential synergies, and “requirements” for a future-fit economic model. The author and initiator of the Economy for the Common Good provides an overview of these „new sustainable economic models“ and compares them according to underlying values, principles, and practical ways of implementation. The keynote addresses the cooperative spirit of the conference and prepares the ground for its public highlight on the eve of June 3rd, the round table with representatives of diverse future-fit economic models.

The era of postgrowth economics | By Matthias Olthaar


The scientific debate on whether economies should always continue to grow increasingly becomes a political and societal debate. On the one hand further growth for the most affluent countries seems neither possible nor valuable, but on the other hand there is still lack of understanding and knowledge what a non-growing economy should look like and could best be governed. In this lecture we discuss various policy measures that can be realistically implemented, take into account government finances and aim at a higher quality of life despite a non-growing economy.

Democratic principles for a sustainable economy | By Lisa Herzog


Democracy is under pressure, and less and less able to stir the economy into a sustainable direction. Therefore, to stabilize democracy and to make possible the socio-ecological transformation of the economy, democratic principles need to be implemented directly in the economy. This is not only a matter of morality, but also has practical advantages. Democratizing the economy can increase legitimacy and take advantage of the “knowledge of the many” to accelerate the transformation. Democratic practices, especially deliberation, allow bringing together different forms of knowledge, which is crucial for the local implementation of principles of social and ecological sustainability. This talk explores what this idea means in more concrete terms, from democratic participation in the workplace to the democratization of time.

Market, state, association, and well-being. An historical approach | By Bas van Bavel


Over the past decades, markets have conventionally been seen as the best instrument to stimulate economic growth and enhance prosperity and well-being. The automatic link between markets and economic growth is increasingly questioned, however, as well as the automatic link between economic growth and enhancement of well-being. This has led to attempts to capture well-being development more directly than through GDP per capita figures and has produced a more variegated picture of well-being growth. Also, this has led to a shift of focus to other coordination systems than the market, as primarily the state but increasingly also the association. Analyses of the historical record suggest that especially the latter could be a vital component in future well-being.