Department of Chemistry, University of Patras, Patras, Greece.
Laboratory of Marine Geology and Physical Oceanography, Department of Geology, University of Patras, Patras, Greece.
Mar Pollut Bull. 2021 Aug;169:112470. doi: 10.1016/j.marpolbul.2021.112470. Epub 2021 May 25.
Environmental pollution from plastic bags is a significant issue in the global environment. Plastic bags can be transferred by the wind and ocean currents everywhere in the three dimensions and be fragmented into small particles, termed film-shaped microplastics. The purpose of this study is to provide insights on the degradation of beached plastic bags. Monitoring and sampling were performed to determine plastic bag fragmentation and the possible mechanisms. On selected samples, various spectroscopic techniques and microscopy were used. Before the imposition of the "green" plastic bag fee in Greece, field monitoring suggested that the majority of the coastal plastic bags were fragmented whereas after the "green" fee, less fragmented bags were observed. Evidence of three degradation mechanisms were observed in this study. For oxodegradable plastic bags, degradation takes place for the starch additives and the polymer part stays in the environment as microplastic particles. For thin light density polyethylene plastic bags, mechanical fragmentation takes place in the environment creating microplastics before significant chemical alterations in functional groups were observed and once chemical alteration (oxidation) is observed, fragmentation (of HC or CC bonds) is also taking place. Thus, regulating thin plastic bags usage removes problems related to plastic bags but also to film-shaped microplastics.
塑料袋造成的环境污染是全球环境的一个重大问题。塑料袋可以通过风和洋流在三维空间中到处转移，并被分解成小颗粒，称为薄膜状微塑料。本研究的目的是提供有关海滩塑料袋降解的见解。进行了监测和采样，以确定塑料袋的碎片化和可能的机制。对选定的样本，使用了各种光谱技术和显微镜。在希腊实施“绿色”塑料袋收费之前，实地监测表明，大多数沿海塑料袋都已碎片化，而在实施“绿色”收费后，观察到的碎片化塑料袋较少。本研究观察到三种降解机制的证据。对于可氧化降解塑料袋，降解发生在淀粉添加剂上，聚合物部分作为微塑料颗粒留在环境中。对于薄型低密度聚乙烯塑料袋，在观察到功能团发生显著化学变化之前，在环境中发生机械碎片化，形成微塑料，一旦观察到化学变化（氧化），也会发生碎片化（HC 或 CC 键）。因此，规范薄型塑料袋的使用不仅可以解决塑料袋问题，还可以解决薄膜状微塑料问题。
