| Abstract [eng] |
Micropollutants such as per- and polyfluoroalkyl substances (PFAS), pharmaceutical compounds, phthalates, and microplastics are being detected in the environment with increasing frequency. The growing occurrence of micropollutants in municipal wastewater poses significant risks to both the environment and human health. In response to these threats, the European Union adopted an updated Urban Wastewater Treatment Directive, requiring EU Member States to implement quaternary wastewater treatment technologies designed for the degradation and removal of micropollutants from wastewater. The aim of these measures is to reduce the release of hazardous substances into the environment, protect water resources, and ensure public health. This master’s thesis examines the applicability of advanced quaternary wastewater treatment technologies for micropollutant removal under real operating conditions. The aim of the study is to evaluate the efficiency of advanced quaternary wastewater treatment technologies and determine optimal process conditions, including ozone concentration, contact time in the ozonation column, and retention time in granular activated carbon filters. The main object of the research is the concentration of micropollutants in municipal wastewater and their removal efficiency using quaternary wastewater treatment technologies. The study focuses on pharmaceutical compounds, PFAS, and phthalates. The research object is the EMPEREST project pilot unit, integrating ozonation and granular activated carbon filtration processes, operated at the JSC “Kauno vandenys” wastewater treatment plant. During this study, the efficiency of the pilot quaternary wastewater treatment unit was evaluated under real wastewater treatment plant operating conditions by applying a combination of ozonation and activated carbon filtration. The main focus was placed on micropollutant removal efficiency, process optimization, and the assessment of the relationship between operational control indicators – the spectral absorption coefficient (SAC/UV254) and dissolved organic carbon (DOC). The research results demonstrated that the highest removal efficiency achieved for PFAS compounds was 84,23 %, for pharmaceutical compounds – 99,64 %, and for phthalates – 85,75 %. Based on the overall evaluation of all micropollutants, the most optimal results were identified in series 4 (average final weighted score – 0,82), applying an ozone dose of 8 gO₃/m³, an ozonation contact time of 20 minutes, and a granular activated carbon filter retention time of 15 minutes. The results of series 4 demonstrated the most favourable balance between micropollutant removal efficiency and process cost-effectiveness. These operating conditions represent the most stable solution for the Kaunas municipal wastewater treatment plant. |
