Caratterizzazione e monitoraggio di macro- e microplastiche in ambienti acquatici marini e fluviali

This PhD thesis addresses the global crisis of plastic pollution in aquatic environments, with the aim of developing and validating innovative, integrated, and accessible analytical methodologies for the monitoring and characterization of plastic materials. Starting from the critical framework of the pervasive accumulation of macro- and microplastics—exacerbated by the environmental persistence of polymers and by fragmented regulatory frameworks—the research focuses on overcoming some of the main methodological gaps currently recognized, namely the difficulty of obtaining truly representative quantification, the limited understanding of degradation processes under natural environmental conditions, and the lack of standardized protocols. The investigative approach is based on the integration of advanced spectroscopic techniques (HSI, FTIR, and portable NIR), chemical–environmental indicators (Carbonyl Index, HI), and isotopic markers (δ¹³C), supported by statistical models and Machine Learning approaches, demonstrating the effectiveness of a multi-parameter framework. The results validate the use of rapid, non-destructive tools for large-scale analyses and highlight the key role of specific indicators in tracing both the origin and degradation state of plastics, providing a level of information that goes well beyond simple concentration measurements. The conclusions emphasize the urgent need to harmonize analytical protocols at the international level and to systematically integrate the proposed methods into structured monitoring programs. Future perspectives point toward the refinement of degradation indices, the expansion of low-cost predictive models, the implementation of isotopic tracing as a forensic tool, and the development of methodologies targeting nanoplastics and plastic additives. Overall, this work provides a methodological contribution aimed at transforming plastic pollution monitoring from a purely descriptive practice into a robust scientific tool, capable of effectively informing policies for the prevention, mitigation, and remediation of this complex environmental challenge.