In this master thesis project, the removal of micro-pollutants (MPs) from water and wastewater were investigated by ozonation and the peroxone process O3/H2O2. Themain aim of the study was to compare the degradation efficiency of the two processes for a selection of organic biocides and active pharmaceutical ingredients (APIs) in wastewater and synthetic water. Synthetic water and wastewater effluent were spiked with fifteen compounds including twelve biocides and three APIs and samples were taken at different time points to determine degradation kinetics in treatment by the two processes, respectively. Most of the biocides tested in this study showed moderately reactivity, or were non-reactive, with O3 (e.g., Carbendazim, 1H-Benzotriazole, 1, 2-Benzisothiazol-3(2H)-one, 2, 4-Dinitrophenol, 4-nitrophenol) and some of the biocides and APIs were readily reactive with ozone (O3) and were removed from the water by direct O3 oxidationduring both processes. Trimethoprim was found to be an ozone reactive micropollutants and showed highest reactivity with O3. In the abatement mechanism, these micro-pollutants are removed based on the ozone-based processes and with hydroxyl radical •OH in peroxone process. Comparing the two processes, the peroxone process showed highest percentage removal of compounds (90-100%) within moderate time periods (30 s - 2 min) in synthetic water and (30 s to 10 min) in wastewater. The results revealed that the peroxone process showed highest removal efficiency and with higher reproducibility. Further, generally

Wastewaters from textile industry contain organic dyes, which cannot be easily treated by biological methods. Therefore, pretreatment by an advanced oxidation process (AOP) is needed in order to produce more readily biodegradable compounds and to remove color and chemical oxygen demand (COD) simultaneously. In this research, ozone (O3) is combined with hydrogen peroxide (H2O2) for the advanced oxidation of an azo dye solution, namely aqueous solution of Acid Red 151, which is called as &ldquo / Peroxone process&rdquo / . The aim of the study is to enhance the ozonation efficiency in treating the waste dye solution. The effects of pH, initial dye and initial ozone concentrations and the concentration ratio of initial H2O2 to initial O3 on color and COD removals were investigated. Also, the kinetics of O3-dye reaction in the presence of H2O2 was approximately determined. As a result of the experimental study, it was seen that an increase in the initial dye concentration at a constant pH and initial ozone concentration did not change the COD % removal significantly, from a statistical analysis of the data. The results obtained at pH values of 2.5 and 7 gave higher oxidation efficiencies in terms of color and COD removals compared to those at pH of 10. The best initial molar ratio of H2O2 to O3 was found to be 0.5, which yielded highest treatment efficiency for each pH value studied. The results of the excess dye experiments suggest that the ozonation of Acid Red 151 follows an average first order reaction with respect to ozone at pH=2.5 and pH=7 whereas it is around 0.56 at pH=10. By Initial Rate Method, the orders with respect to individual reactants of O3 and dye were determined as one, the total order of the reaction being two for all the studied pH. As a conclusion, a further study of the peroxone process at a pH of 10 can be recommended to determine the reaction kinetics and mechanism at this pH, where radicals play an important role.