ITA: Tecniche Avanzate di Quantificazione e Strategie Sostenibili di Risanamento per I'lnquinamento da Micro e Nanoplastiche: focus sul rilascio delle Fibre Tessili. EN: Advanced Quantification Techniques and Sustainable Remediation Strategies for Micro- and Nanoplastic Pollution: a focus on Textile Fiber release

This thesis investigates the occurrence, impacts, and mitigation of microplastics (MPs) pollution, with a particular focus on synthetic microfibers (MFs) originating largely from textile washing. MPs, defined as synthetic polymer particles measuring ≤ 5 mm, are pervasive in marine, freshwater, and subterranean habitats, and are recognized for their propensity to adsorb and transport harmful chemicals and pathogens. MFs, among the most abundant MP forms, pose additional concerns due to their potential to affect complex trophic networks and to move across ecological compartments. To address key knowledge gaps, the thesis integrates field monitoring, analytical innovations, and remediation research. First, extensive sampling in urban streams and freshwater fauna establishes the widespread distribution of MPs and MFs, identifying new ecological risks. Notably, the research documents substantial ingestion of MPs and textile cellulose fibers by meiofaunal communities and reports the first known instance of MP ingestion by a freshwater stingray. Second, the thesis presents new methods to enhance MP detection. A fluorescence-based protocol using Nile Red dye efficiently detects micro- and nanoplastics down to around 1 μm, while automated static particle analysis (ASPA) improves throughput and reduces operator bias, thus enabling more robust quantification. Finally, two cutting-edge mitigation strategies are advanced: magnetic micro/nanoparticles (MNPs) capable of removing over 80% of MFs under optimal conditions, and a novel bacterium with the potential to degrade low-density polyethylene (LDPE). These findings support integrative remediation solutions combining physical separation and biological degradation to lessen MP loads in wastewater before discharge. Overall, this work enriches the current understanding of the ecological reach of MPs and MFs, provides standardized tools for their detection and characterization, and proposes advanced, scalable remediation approaches. By linking fundamental research with applied solutions, the thesis informs policy, promotes methodological harmonization, and high lights viable pathways to reduce the environmental footprint of plastic pollution.