Shape analysis of microplastic fragments: A computed microtomography study

Microplastic (MP) pollution represents a critical environmental challenge, yet comprehensive characterization of MPs fragments remains an area lack of in-depth research. This study highlights the potential of X-ray microtomography (microCT) to enhance our understanding of microplastics characteristics. Five small plastic Polyethylene Terephthalate (PET) fragments, approximately 2.0 mm in diameter, which are secondary in origin and exhibit irregular shapes were analyzed. Through optimized scanning parameters, a voxel size of 6.0 μm were achieved and advanced image processing techniques to improve the visualization of these low-density materials were employed. Morphometric analysis was performed using three key parameters: elongation, flatness, and sphericity, enabling a nuanced classification of the fragments. There is a significant morphological diversity among the samples, emphasizing the necessity of a multi-parameter approach for effective classification. Additionally, microCT enabled the visualization of internal structures, such as cracks, which are indicative of degradation processes. This research underscores microCT's utility in elucidating the complex behavior and environmental impact of MP pollution, while highlighting the need for further studies to refine our classification methodologies and deepen our understanding of MP formation and degradation.