Challenges and technological approaches for tackling emerging microcontaminants in wastewater

Emerging microcontaminants (EMCs), such as microplastics (MPs), per- and poly-fluoroalkyl substances (PFAS), and organic ultraviolet filters (OUVAs), pose significant threats to aquatic ecosystems and human health due to their persistence, toxicity, and bioaccumulation potential. Conventional wastewater treatment plants (WWTPs) are often inadequate in tackling EMCs, necessitating innovative and cost-effective approaches for their detection and removal. This PhD research addresses these challenges by advancing sustainable wastewater treatment technologies and developing novel analytical methods for EMC monitoring. The first research objective focused on evaluating and optimizing nature-based solutions (NBSs), particularly constructed wetlands (CWs), for EMC mitigation. Full-scale studies of hybrid and multi-cell CW systems in Italy and the UK revealed key design parameters influencing the removal efficiency of MPs and PFAS, including substrate composition, hydraulic design, and influent type. Pilot-scale experiments demonstrated enhanced performance of microbial electrochemical technology (METland) systems using electroconductive media, achieving superior degradation and retention of MPs and PFAS compared to conventional gravel CW designs. These findings highlight the potential of CWs as sustainable, scalable solutions for EMC pollution control. The second objective of the present PhD thesis centered on overcoming the analytical challenges of chromatographic techniques by developing novel electrochemical molecularly imprinted polymer (MIP)-based sensors tailored for OUVA detection. The affinity sensors exhibited high specificity and sensitivity for detecting benzophenone-3 (BP-3) and octocrylene (OC) in complex wastewater matrices, offering a cost-effective and portable alternative to commonly employed analytical methods. The successful validation of these devices in the presence of potential interferents and wastewater samples underscores their applicability for real-time and large-scale environmental monitoring. This research provides a comprehensive framework for integrating NBSs and advanced sensing technologies into holistic wastewater management, bridging the gap between laboratory-scale studies and extensive applications.