Tallinn University of Technology

The solution created by the researchers of Tallinn University of Technology enables the removal of persistent pollutants from water and air much more efficiently than before, but the implementation of the new technology unfortunately depends on both funding and the interest of the state and the private sector.

Sergei Preis
Professor Sergei Preis

The new technology means combining pulsed corona discharge with catalytic/photocatalytic processes and maximising energy efficiency, which in the context of the current green transition can be viewed as a last resort that a world drowning in pollution should seize.

The head of the research group, Professor Sergei Preis of Tallinn University of Technology, admits that he considers the most important result of this research to be the fact that the new technology is as much as 2.5 to 3 times more energy efficient than the existing ones. And this applies to the treatment of any new water and air pollutants. ‘In the course of the research process, we also discovered factors that affect the process in a so-called unexpected way, but it is indeed this element of unexpectedness that makes the research interesting,’ says Preis.

How was the result reached?

The development of new efficient treatment technologies aimed to remove persistent micro-pollutants, carcinogenic nitroso compounds and volatile compounds from water, air and sludge. The research involved combinations of corona discharge with Fenton-type oxidation and gas-phase photocatalysis, analysing the efficiency of the process, the course of the reaction, and possible limitations. As a result, the most suitable process conditions were determined.

A prerequisite for the implementation of this technology and for ensuring better safety was the quantitative evaluation of the parameters of this highly efficient process for the decomposition of various pollutants.

This approach is a major breakthrough in the use of energy-efficient and human-friendly technologies in water treatment and environmental protection.

Truly creative work

Decomposition of pollutants with unprecedented or even incomparable energy efficiency has been achieved with the use of pulsed corona discharge (PCD) for persistent micropollutants, endocrine disruptors, medicinal products, pesticides, textile colourants, carcinogens and volatile compounds in water and air. Experimental studies of PCD, combined with external oxidants and gas-phase photocatalysis, allowed to optimise the process parametres for water and air pollutants, providing a basis for PCD applicability, scalability and safety.

Preis was pleased that the members of the research team came up with various new ideas and got constructive results, developing the technology in unexpected ways. ‘It was a truly creative process,’ says Professor Preis.

Will the result of the research be applied in real life?

The aim of the researchers is to characterise the process of purification of water, air and sludge with plasma and catalysis in such detail that the risks of scaling the technology can be mitigated to the maximum, but according to Sergei Preis it is no longer a task for the researchers alone, but a collaboration work with partners. According to Preis, in terms of the development of new technology, there is hope that the researchers of Tallinn University of Technology will also be able to contribute to its scaling. ‘We also hope that the Laboratory of Environmental Technology will continue to operate for more than one year, because being a 100% concern of the state or society, environmental technology will not find a private investor unless it is a producer of water or air treatment infrastructure,’ explains Preis. Unfortunately, there are no such investors here in Estonia or nearby.

The project ‘Innovative energy-efficient abatement of aqueous and airborne hazardous pollutants combining pulsed corona discharge plasma with catalysis/photocatalysis’ was funded by the Estonian Research Council.