Researcher Matías Rivadulla Cora focused his doctoral thesis on the development and evaluation of innovative systems to improve the removal of emerging contaminants from urban wastewater, specifically pharmaceutical compounds and antimicrobial resistance genes. The research addressed both centralised wastewater treatment systems and novel decentralised approaches aimed at enabling the safe reuse of water and reducing the environmental impact of these contaminants. The thesis was supervised by CRETUS researchers from the Department of Chemical Engineering, Professors Juan Manuel Garrido Fernández and Francisco Omil Prieto, and was carried out at the CRETUS Research Centre within the Environmental Biotechnology Group (BioGroup).
The growing presence of emerging contaminants in wastewater—including antibiotics, painkillers, hormones and antimicrobial resistance genes—has become one of the major environmental and public health challenges worldwide. Increased consumption of these compounds, together with the inability of conventional wastewater treatment systems to remove them completely, promotes their release into the environment and increases the risk of spreading antibiotic-resistant bacteria. Against this backdrop, the European Union has recently strengthened its requirements for urban wastewater treatment and the safe reuse of water, driving the development of new technologies capable of improving contaminant removal and minimising their environmental impact.
This was precisely the focus of the thesis: to evaluate and develop new treatment strategies capable of enhancing the removal of emerging contaminants from urban wastewater, while investigating their behaviour in both centralised treatment systems and decentralised configurations based on the separation of blackwater and greywater. To achieve this, the research combined studies in full-scale wastewater treatment plants across Galicia with pilot-scale experiments conducted at the Silvouta Wastewater Treatment Plant for centralised systems and at the Porto do Molle Business Centre (Nigrán) for the decentralised configuration. In addition, mechanistic laboratory studies were carried out using advanced membrane-based biological systems, anaerobic processes and intensification technologies such as activated carbon and microbial bioaugmentation to improve treated water quality without requiring major infrastructure investments. This approach made it possible to analyse the behaviour of pharmaceutical compounds, resistant bacteria and other contaminants under real operating conditions, while also assessing the potential of new treatment configurations designed to support the safe reuse of water.
The findings demonstrated that advanced biological systems can significantly improve the removal of emerging contaminants from urban wastewater. The thesis showed that certain innovative configurations were capable of removing more than 90% of some pharmaceutical compounds, including specific antibiotics, while also substantially reducing the presence of resistant bacteria and antimicrobial resistance genes. The research further confirmed the potential of decentralised systems based on blackwater and greywater separation to tailor treatment processes to the characteristics of each wastewater stream and facilitate safer water reuse. Likewise, intensification strategies such as activated carbon and specialised microbial communities proved effective in improving the performance of conventional treatment processes and reducing the environmental impact associated with the discharge of these contaminants into natural ecosystems. Importantly, these strategies were demonstrated under real operating conditions, bringing them a step closer to practical implementation and commercial deployment.
The research was conducted at CRETUS, a member of the CIGUS Network and co-funded by the European Union through the Galicia ERDF 2021–2027 programme. It was carried out within the framework of the PRESAGE project (ERA-NET AquaticPollutants) and the ANTARES project (Spanish State Research Agency), both focused on emerging contaminants and innovative strategies for protecting water resources. In addition, some of the decentralised systems evaluated in the thesis were developed in collaboration with FCC Aqualia, promoting knowledge transfer and supporting the practical application of the technologies under study.
The results of this research have led to several scientific publications in leading international journals in the fields of environmental engineering and water treatment, including Science of the Total Environment, Journal of Hazardous Materials and Journal of Environmental Management. The work also fostered collaborations with international research centres and organisations and contributed to the development and validation of technologies under real operating conditions, strengthening the link between scientific research and technology transfer within the water sector. The thesis was awarded the distinction of cum laude with honours.
