Tallinn University of Technology

At the end of the last year, Irina Epold defended her doctoral thesis "Degradation of Pharmaceuticals by Advanced Oxidation Technologies in Aqueous Matrices" at the Department of Chemical Engineering.

The presence of pharmaceuticals in surface water, groundwater and wastewater has become a subject of worldwide environmental concern. The compounds originating mainly from industrial, agricultural, and domestic wastes represent one of the greatest challenges to environmental technology due to the intrinsic high toxicity, low biodegradability and resistance to conventional biological treatment methods. The application of advanced oxidation technologies (AOTs), particularly radical-based processes, seems to be the most viable solution to the problem of pharmaceuticals contamination. The doctoral thesis evaluated the potential of different advanced oxidation technologies in degradation of pharmaceuticals representing two important and most widespread groups of drugs in water. The drugs investigated were non-steroidal anti-inflammatory analgesics ibuprofen and diclofenac and antimicrobial drugs sulfamethoxazole and levofloxacin.

The supervisor of the doctoral thesis, Marina Trapido, Professor at the Department of Chemical Engineering, explains: "Today, there is a wide range of new chemicals: preservatives and colourants in foodstuffs, fabric dyes, all kinds of pesticides, home care products, etc. that are released into surface water, groundwater and wastewater. According to surveys, very often these do not decompose at all. Ten, sometimes even up to ninety per cent of such micropollutants, pass through water treatment plants and are released into nature, where they cause problems. Industrial waste water contains micropollutants in particularly large amounts and it would be reasonable to remove them."

One way of getting rid of hazardous micropollutants is for example to absorb them with activated carbon, but this method is relatively expensive. Another way is to degrade them. And this is where advanced oxidation processes could be applied to generate hydroxyl and other radicals, such as sulphate radicals, which are so powerful oxidants that they degrade almost all harmful organic substances found in water. This method has been studied for decades, but it has been taken into use in environmental protection only relatively recently.

Supervisors: Marina Trapido and Senior Research Scientist Niina Dulova (TUT).
Opponents: Professor Tatyana Poznyak (National Polytechnic Institute of Mexico) and Dr. Artur Jõgi (OÜ Liprafarm, Estonia).

The doctoral thesis has been published in the digital collection of the library at http://digi.lib.ttu.ee/i/?3698