The possibilities for reducing toxic air pollution have been investigated for many years under the leadership of Marina Kritševskaja, Senior Research Scientist at the Laboratory of Environmental Technology of the Department of Materials and Environmental Technology. An article titled "Gas-phase photocatalytic oxidation of refractory VOCs mixtures: Through the net of process limitations" will be published in the international scientific journal Catalysis Today, where Marina Kritševskaja with her colleagues from the Clausthal University of Technology in Germany and South China University of Technology will provide a mid-term review of the research.
People in developed countries spend over 90% of their lifetime indoors, which is why good air quality is very important. When buildings are constructed and furnished with modern synthetic materials, toxic compounds may spread in indoor air. The Laboratory of Environmental Technology investigates methods for decomposition of such air pollutants (including volatile organic compounds, hydrocarbons).
In industrial premises toxic volatile compounds are released into the air from the abovementioned construction and furnishing materials but also, for instance, from the chemicals used in the manufacture of plastic materials and in the wood industry (e.g. solvents in the composition of adhesives and resins). Outdoor air pollution is caused for example by exhaust gases from vehicles.
One of the modern methods for cleaning air from pollutants is decomposition of the pollutants by photocatalytic oxidation. This means that decomposition is carried out with highly active compounds, radicals, generated by light energy in presence of catalysts.
"Our research consists of two parts - first a catalyst needs to be synthesised for carrying out the treatment process and, secondly, the most optimal, the best conditions for carrying out the treatment process need to be determined," Kritševskaja explains. "In search for a catalyst we defined the certain direction to focus on in the development of catalytic material already in 2015, and now, in parallel to that,we are optimising the treatment process.“
Why is it important? The conditions of the treatment process shall be such that the catalyst would perform in a long term and decompose the pollutants as effectively as possible without forming any toxic intermediate by-products (an intermediate by-product may form in the course of chemical decomposition and it can be even more toxic than the parent compound).
Marina Kritševskaja believes that they will achieve the best result in photocatalytic air treatment in the next few years. Research is carried out in two lines - development of a powder catalyst in collaboration with colleagues from the Clausthal University of Technology and development of a thin-film catalyst in collaboration with the research group of the Lead Research Scientist Malle Krunks and Senior Research Scientist Ilona Oja Acik at the Department of Materials and Environmental Technology of Tallinn University of Technology.
Kersti Vähi, TTÜ Research Administration Office