The fate and removal of micropollutants and antibiotic resistance in aerobic granular sludge systems

Emerging contaminants, including micropollutants (OMPs), antibiotic resistant bacteria (ARB), and their genes (ARGs), are frequently detected in municipal wastewater and are only partially removed by conventional activated sludge systems. Aerobic granular sludge (AGS) process offers a promising alternative, but its granule size distribution and batch-fed operation lead to different treatment dynamics. To date, the fate and removal of these contaminants in full-scale AGS systems, especially regarding granule size fractions and wet-weather impacts, remain poorly understood. This thesis investigates OMP removal via sorption and biotransformation, and ARB (Escherichia coli) elimination through protozoan predation or other mechanisms across six AGS size fractions. Larger granules enhanced OMP sorption and E. coli predation, while smaller fractions contributed more to OMP biotransformation and ARG dissemination. Full-scale monitoring showed reduced OMP and ARG removal during wet weather due to operational adjustments. Overall, this thesis assesses the potential of AGS process for controlling emerging contaminants and proposes strategies to enhance their removal by optimising granule size distribution and operational parameters.