Evaluating the Fate of Emerging Contaminants in Wastewater Treatment Plants through Plant-Wide Mathematical Modelling

Wastewater treatment plants are one of the major routes transporting emerging contaminants (ECs) to the water environment. Mathematical modelling is an essential tool to assess the fate of ECs through wastewater treatment. In the context of this study, a plant-wide mathematical model was developed and calibrated. According to the results, the dominant removal mechanisms have been identified for each target compound, thus confirming previously published data on their physicochemical properties. Solids retention time is an important operating parameter which highly influences the removal rate of most biodegradable ECs, while the performance of primary sedimentation, with regard to solids removal, influences the fate of both soluble and particulate fraction of ECs. Furthermore, the increase of solids capture rate in sludge thickening and dewatering units is associated with a decrease in ECs removal rate and their content in biomass. The hourly fluctuations in the inflow loads of ECs result in a variation of effluent ECs concentration with the same periodicity but with a significantly lower range.