This study simulates a major environmental scenario involving “organic fertilizer source” plastics, by exploring the key factors influencing the changes in plastic-films during anaerobic digestion (AD), as well as the responses of the anaerobically digested plastics to ultraviolet (UV) radiation exposure. The results demonstrate that the degradation effect of AD on plastics is reflected by their yellowish and ruptured appearance, slightly worn surfaces, hardening and opacity, and fragmentation. AD significantly increases the content of oxygen-containing functional groups and the degree of unsaturation in plastic films, with thermophilic temperature processes proving more effective than those conducted at mesophilic temperatures. Exposure to UV light has been found to amplify the degradative effects, suggesting the potential cumulative impact of AD and UV. Both AD and UV irradiation reduced the hydrophilicity of plastics. In particular, the hydrophobicity of polylactic acid films was completely disrupted under overlay-exposure. Furthermore, microbial populations on plastic surfaces were mainly bacterial. These bacterial populations were primarily influenced by temperature, and moderately by the plastic types. In contrast, archaea were predominantly affected by both temperature and digested substrate. This study offers a theoretical foundation for strategies aimed at preventing and controlling plastic pollution derived from organic fertilizers.

中文翻译：

---

厌氧消化源头的塑料薄膜：表面降解、生物膜和紫外线响应特性


本研究通过探索厌氧消化 （AD） 过程中影响塑料薄膜变化的关键因素，以及厌氧消化塑料对紫外线 （UV） 辐射暴露的反应，模拟了涉及“有机肥料来源”塑料的主要环境情景。结果表明，AD 对塑料的降解作用反映在塑料的淡黄色和破裂外观、轻微磨损的表面、硬化和不透明以及碎裂。AD 显着增加了塑料薄膜中含氧官能团的含量和不饱和度，事实证明，嗜热温度过程比在嗜温温度下进行的过程更有效。已发现暴露于紫外线会放大降解效应，表明 AD 和 UV 的潜在累积影响。AD 和 UV 照射都降低了塑料的亲水性。特别是，聚乳酸薄膜的疏水性在叠加曝光下完全被破坏。此外，塑料表面的微生物种群主要是细菌。这些细菌种群主要受温度影响，适度受塑料类型的影响。相比之下，古细菌主要受温度和消化底物的影响。本研究为旨在预防和控制有机肥料产生的塑料污染的策略提供了理论基础。