On 29 April at 12:15 Kati Klein will defend her doctoral thesis “Studies and treatment of inhibitory and recalcitrant wastewater” in environmental technology.
Associate Professor Taavo Tenno, University of Tartu
Professor Anna Mikola, University of Aalto (Finland)
Municipal wastewater containing different pollutants is produced in our homes every day. It is subjected to wastewater treatment plant (WWTP), where microorganisms consume these pollutants. Industrial wastewater containing inhibitory substances is frequently subjected to municipal WWTP-s, which causes the inhibition of wastewater treatment processes. Consequently, wastewater treatment efficiency decreases and pollutants may be subjected to the water bodies. Different technologies are available for inhibition removal, but there were no applicable and reliable methods found for all main wastewater treatment processes. Additionally, industrial wastewater may contain biorefractory organic substances and thereby require application of advanced treatment methods, e.g. the Fenton process. The Fenton process is an advanced oxidation process which application is limited by high operational costs due to high chemical consumption and production of hazardous ferric waste sludge. Three significant problems of inhibitory and recalcitrant wastewater treatment were solved with this thesis. Firstly, optimal conditions for inhibition tests were found to estimate the impact of wastewater or inhibitory substance on wastewater treatment processes for which no reliable standard methods were found – activated sludge enhanced biological phosphorus removal and for the second step of nitrogen removal, denitrification. Inhibition tests are applied to estimate the feasibility of activated sludge processes to treat a certain wastewater and to identify the origin of wastewater causing wastewater treatment problems. Secondly, combined activated sludge and physical-chemical treatment of complex wastewater was tested considering results from preliminary inhibition and biodegradability studies, which increased the treatment efficiency and reduced cost of complex wastewater treatment. Thirdly, operation the Fenton process was modified to reduce the production of ferric waste sludge and consumption for chemicals.
Access to the defence: https://us02web.zoom.us/j/89627999036?pwd=QzUra3J5czcxRTVFQ09jQkR1WWM5Zz09#success.