“There is something so refreshing about drinking water straight from the source”,
says Roman Klymenko when sharing his adventures of hiking in the mountains with breathtaking views and crystal-clear lakes. However, in many other places drinking water straight from the source is not a good idea. Many of our water bodies are of poor quality due to the presence of a large variety of pollutants, and that is exactly what Roman is studying here at Wetsus: treating contaminated wastewater.
Roman is a third-year PhD student here at Wetsus as part of the research theme Applied Water Physics. He is from Ukraine and did his studies in Kyiv, where he specialized in Plasma Technology and Electron Physics. For his PhD, he attempts to treat wastewater by combining plasma discharge with water vortex to degrade micropollutants.
But first of all, what is plasma? Plasma is a state of matter that can be reached when even more energy is put into the gas state. In this way, electrons are stripped from the gas molecules, resulting in an ionized gas: plasma. And how does Roman manage to apply it in water technology? With knowledge in fundamental plasma physics and experience in fixing antique furniture and electronics, he has built a setup consisting of a water vortex basin and a plasma generator. By concentrating electrical energy on the tips of the electrodes of the plasma generator, a high-voltage plasma discharge can be ignited between the electrodes and the water’s surface.
These discharges induce various processes that contribute to the water treatment qualities of the technology. Plasma discharges can easily destroy atomic bonds in compounds present at the surface of the wastewater. In this way, the micropollutants can be broken down. Besides, resulting UV radiation, shock waves, and the formation of radicals (reactive species) have an additional breakdown effect in the bulk of the wastewater. Roman’s focus started on breaking down pharmaceuticals, but he has currently shifted to PFAS. It turned out that the ‘forever chemical’ is not so everlasting when exposed to plasma discharge.
An important steppingstone in his career orientation was the moment towards the end of his bachelor’s when Roman realized he had a passion. When asked to elaborate on this, Roman shows a video on his phone with a lab setup containing a vacuum lamp. In this experiment, plasma discharges were used to fully achieve a vacuum in the lamp by removing any gas residue in the light bulb’s metal wiring. His phone lights up as the plasma discharges shoot through the lamp. His face lights up too, as he relives this moment where “the boy in him got to play in the lab” and found his true passion: plasma.
At his old university in Kyiv, with strict but interesting and well-qualified teachers from the former Soviet Union, who could even manage to “make science with a lot of equations interesting,” Roman was inspired to pursuit a career in research even further. After finishing his master’s, Roman wanted to find a PhD position. The location did not really matter, as long as it would focus on plasma. Then he found the perfect spot at Wetsus, and now he is about to go into the last year of his PhD journey. Currently, the aim of his research is to organize a pilot scale set-up of the plasma treatment technology to gradually move from the lab to real-life practice.
Regarding Roman’s plans for after his PhD chapter, he was a little reluctant to respond directly: “In Ukraine, we have this saying that by admitting your plans and dreams, you might spoil them in the future.” However, he did promise that his future path would definitely remain in research, and perhaps someday, Roman will contribute to the possibility of drinking water straight from the source anywhere, and not only in a serene spot in the mountains.
