Advanced oxidation processes (AOPs) have been studied and developed to suffice the effectiveremoval of refractory and toxic compounds in polluted water. The quality and cost of wastewatertreatment need improvements, and electric discharge technology has a potential to make asignificant difference compared to other established AOPs based on energy efficiency. Thegeneration of active oxidant species such as ozone and hydroxyl radicals by high voltage dischargeis a relatively new technology for water treatment. Gas-phase pulsed corona discharge (PCD),where a treated aqueous solution is dispersed between corona-producing electrodes free of thedielectric barriers, was developed as an alternative approach to the problem. The short livingradicals and ozone formed in the gas phase and at the gas-liquid interface react with dissolvedimpurities. PCD equipment has a relatively simple configuration, and with the reactor in anenclosed compartment, it is insensitive towards gas humidity and does not need the gas transport.In this thesis, PCD was used to study and evaluate the energy efficiency for degrading variousorganic compounds, as well as the chemistry of the oxidation products formed. The experimentsinvestigate the aqueous oxidation of phenol, humic substances, pharmaceutical compounds(paracetamol, ibuprofen, indomethacin, salicylic acids, -estradiol), as well as lignin degradationand transformation to aldehydes. The study aims to establish the influence of initial concentrationof the target pollutant, the pulsed discharge parameters, gas phase composition and the pH on theoxidation kinetics and the efficiency. Analytical methods to measure the concentrations of thetarget compounds and their by-products include HPLC, spectrophotometry, TOC and capillaryelectrophoresis.The results of the research included in this summary are presented in the attached publicationsand manuscripts accepted for publication. Pulsed corona discharge proved to be highly effective inoxidizing each of the target compounds, surpassing the closest competitor, conventional ozonation. The increase in oxidation efficiencies for some compounds in oxygen media and atlower pulse repetition frequencies shows a significant role of ozone. The role of the ·OH radicalswas established in the surface reactions. The main oxidation products, formation of nitrates, andthe lignin transformation were quantified.A compound specific approach is suggested for optimization of the PCD parameters that have themost significant impact on the oxidation energy efficiency because of the different characteristicsand responses of the target compound to the oxidants, as well as different admixtures that arepresent in the wastewater. Further studies in the method’s safety (nitration and nitrosation oforganic compounds, nitrite and nitrate formation enhancement) are needed for promoting themethod.
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