Plastic litter fate and contaminant transport within the urban environment, photodegradation, fragmentation, and heavy metal uptake from storm runoff
Plastic litter fate and contaminant transport within the urban environment, photodegradation, fragmentation, and heavy metal uptake from storm runoff
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城市环境中的塑料垃圾归宿和污染物迁移、光降解、破碎以及风暴径流中的重金属吸收
DOI：
10.1016/j.envres.2022.113183
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发表时间：
2022
影响因子：
8.3
通讯作者：
Fujiwara, Tomoko
中科院分区：
文献类型：
--
作者：
Hadiuzzaman, Md;Salehi, Maryam;Fujiwara, Tomoko
城市垃圾中很大一部分是塑料，污染环境，威胁生态安全。塑料垃圾转化为称为微塑料（MP）的小碎片，通过促进其运输和改变其物理化学特征来加剧其关键风险。本研究以低密度聚乙烯（LDPE）和聚对苯二甲酸乙二醇酯（PET）为主要成分的城市垃圾为研究对象。通过表面化学和形貌分析研究了LDPE和PET MP在加速老化实验中的光降解。通过创新的加速机械风化实验，模拟MPs与道路沉积物的磨损，MPs的光降解对其破碎行为的影响进行了评估。此外，作为车辆的MPs运输的重金属从城市环境中的水资源的作用进行了评估，通过研究铅（Pb）的吸收动力学的新的和风化的MPs在合成雨水。表面形貌的调查显示，银纹的形成和裂纹网络上的MPs由于风化实验。表面化学分析揭示了几个氧化的碳表面官能团的光降解的MP和它们的增加的易感性，由于与道路沉积物的磨损碎片的产生。光降解使LDPE和PET MP上的Pb累积量从467 μg/m2和21 μg/m2增加到2290 μg/m2和725 μg/m2。在这项研究中开发的基础知识提供了一个更好的概念性的了解机制控制MP持久性和污染物在城市环境中的传输，这是至关重要的，以估计其对生态系统的负面影响。
A significant portion of urban litter is plastic which contaminates the environment and threatens ecological safety. The conversion of plastic litter into small fragments called microplastics (MPs) intensifies their critical risks by facilitating their transport and altering their physicochemical features. This study focuses on low density polyethylene (LDPE) and polyethylene terephthalate (PET) as the main components of urban litter. The photodegradation of LDPE and PET MPs due to the accelerated weathering experiments is investigated through surface chemistry and morphology analysis. The influence of MPs’ photodegradation on their fragmentation behavior is evaluated through the innovative accelerated mechanical weathering experiments that simulated the abrasion of MPs with the road deposits. Furthermore, the role of MPs as the vehicles to transport the heavy metals from the urban environment to the water resources is evaluated by studying the kinetics of lead (Pb) uptake by new and weathered MPs in synthetic stormwater. The surface morphology investigation revealed the formation of crazes and the crack networks onto the MPs due to the weathering experiments. The surface chemistry analysis revealed the generation of several oxidized carbon surface functional groups onto the photodegraded MPs and their increased susceptibility to fragmentation due to the abrasion with the road deposits. The photodegradation increased the Pb accumulation onto the LDPE and PET MPs from 467 μg/m2and 21 μg/m2to 2290 μg/m2and 725 μg/m2, after five days of metal exposure. The fundamental knowledge developed in this research provides a better conceptual understanding of the mechanisms controlling MPs persistence and contaminant transport within the urban environment, which is crucial to estimate their negative impacts on the ecosystem.