Eawag - Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600, Dübendorf, Switzerland.
EMPA - Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland.
Water Res. 2019 May 15;155:423-430. doi: 10.1016/j.watres.2019.02.044. Epub 2019 Feb 26.
The increased use of synthetic textiles in the last decades, coupled with recent emphasis on the accumulation of (micro)plastic across multiple environmental compartments, has garnered interest into how microplastic fibers are released into the environment. In particular, polyester textiles washed in the home have shown to release microplastic fibers but challenges with microplastic fiber analysis, including time and difficulty of sample preparation and measurement, has limited mechanistic studies on fiber fate and transport studies. In this study, we provide a method to synthesize fibers with an embedded inorganic (In) fingerprint which can be used as a tracer for ease of analysis and show the utility of this approach to assess the affinity for heteroaggregation between microplastic fibers and other particles in a heterogeneous suspension, as well as approximate the fate of microplastic fibers in batch studies using activated sludge from a municipal wastewater treatment plant (WWTP). Total In content in the fibers was measured to be 0.2 % by weight, which was low enough to not change fiber dynamics for fate and transport studies (e.g. density, etc.) but provided sensitive detection limits by ICP-MS. Fiber length was 510 μm ± 410 μm and 30 μm in diameter. The incorporated metal remained stable inside the polymer when suspended in water and in activated sludge, with < 0.1 % In leaching over two months. In batch experiments, the majority of fibers were associated with the sludge ( > 99.9 %), with a mass balance of > 95 % recovery achieved on average across batches. Fiber removal linearly increased with contact times of up to 10 min, suggesting interactions between plastics and organic matter is a metric that should be considered closely in this and other environmental contexts for fate and transport.
在过去几十年中，合成纺织品的使用增加，加上最近强调（微）塑料在多个环境隔室中的积累，人们对微塑料纤维如何释放到环境中产生了兴趣。特别是，在家中洗涤的聚酯纺织品已显示出释放微塑料纤维的能力，但微塑料纤维分析存在挑战，包括样品制备和测量的时间和难度，限制了对纤维命运和传输研究的机制研究。在这项研究中，我们提供了一种合成纤维的方法，纤维中嵌入了无机（In）标记物，可以作为分析的示踪剂，并且展示了这种方法的实用性，用于评估微塑料纤维与异质悬浮液中其他颗粒之间的异质聚集亲和力，以及使用来自城市污水处理厂（WWTP）的活性污泥在批量研究中近似微塑料纤维的命运。纤维中的总 In 含量通过重量计为 0.2%，这足以不改变纤维的命运和传输研究的动力学（例如密度等），但通过 ICP-MS 提供了灵敏的检测限。纤维长度为 510μm±410μm，直径为 30μm。当悬浮在水中和活性污泥中时，金属仍稳定地存在于聚合物中，在两个月内，In 的浸出率小于 0.1%。在批量实验中，大多数纤维与污泥有关（>99.9%），平均每个批次的回收率都超过 95%。纤维去除率与接触时间呈线性增加，最高可达 10 分钟，这表明塑料和有机物之间的相互作用是在这种和其他环境情况下应密切考虑的命运和传输的一个指标。
