Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China.
Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China.
Environ Pollut. 2021 Jan 15;269:115905. doi: 10.1016/j.envpol.2020.115905. Epub 2020 Oct 20.
Intentional or incidental thermal changes inevitably occur during the lifecycle of plastics. High temperatures accelerate the aging of plastics and promote their fragmentation to microplastics (MPs). However, there is little information available on the release of MPs after fires. In this study, an atomic force microscope combined with nanoscale infrared analysis was used to demonstrate the physicochemical properties of polypropylene (PP) plastics under simulated fire scenarios. Results showed that the chemical composition and relative stiffness of heat-treated plastic surfaces changed, significantly enhancing the generation of MPs under external forces; over (2.1 ± 0.2) × 10 items/kg abundance of MPs released from PP which were burned at 250 °C in air and trampled by a person. The leaching of antimony (Sb) from MPs in different solutions first increased and then decreased with increasing temperature, reaching a maximum at 250 °C. Higher concentrations of humic acid (10 vs 1 mg/L) caused a greater release of Sb. Furthermore, the tap water leachates of PP burned at 250 °C had the greatest effect on the growth and photosynthetic activity of Microcystis aeruginosa. Our results suggest fires as a potential source of MPs and calls for increased focus on burning plastics in future research.
在塑料的生命周期中，不可避免地会发生有意或无意的热变化。高温会加速塑料老化，并促使其碎裂成微塑料（MPs）。然而，关于火灾后 MPs 的释放情况，相关信息却很少。在这项研究中，我们使用原子力显微镜结合纳米级红外分析，展示了模拟火灾场景下聚丙烯（PP）塑料的理化性质。结果表明，受热处理塑料表面的化学成分和相对硬度发生了变化，显著增强了在外力作用下 MPs 的生成；在空气中 250°C 燃烧并被人踩踏后，从 PP 中释放出的 MPs 数量超过（2.1±0.2）×10 项/kg。不同溶液中 MPs 中锑（Sb）的浸出量随温度的升高先增加后减少，在 250°C 时达到最大值。较高浓度的腐殖酸（10 与 1mg/L）会导致 Sb 的释放量更大。此外，在 250°C 燃烧的 PP 的自来水浸出物对铜绿微囊藻的生长和光合作用活性影响最大。我们的研究结果表明火灾是 MPs 的潜在来源之一，并呼吁在未来的研究中更多地关注燃烧塑料的问题。
