论文标题
在连续级联碎片的影响下建模海洋塑料的大小分布
Modelling size distributions of marine plastics under the influence of continuous cascading fragmentation
论文作者
论文摘要
现场研究表明，就丰度而言，塑料碎片构成了海洋中的大多数塑性污染。但是，环境塑料碎片的速度尚未得到充分理解。在这里，我们通过考虑一个模型来研究这种碎片化过程，该模型以级联的方式捕获了颗粒的连续碎片。使用这种级联碎片模型，我们模拟粒度分布（PSD），指定不同尺寸类别的粒子的丰度或质量。碎裂模型与环境盒模型耦合，模拟了海洋，沿海水域和海滩上塑料颗粒的分布。我们将建模的PSD与可用的观测值进行了比较，并使用结果来说明尺寸选择过程的效果，例如水柱中的垂直混合以及从海滩重悬于沿海水域的颗粒。该模型量化了碎片在海洋塑料质量预算中的作用：虽然碎片是（次级）塑料颗粒的主要来源，但它似乎对大于0.1 mm的颗粒的总质量有很小的影响。与观察到的PSD数据的未来比较使我们能够了解环境中的尺寸选择性塑料运输，并有可能告知我们塑料寿命。
Field studies have shown that plastic fragments make up the majority of plastic pollution in the oceans in terms of abundance. How quickly environmental plastics fragment is not well understood, however. Here, we study this fragmentation process by considering a model which captures continuous fragmentation of particles over time in a cascading fashion. With this cascading fragmentation model we simulate particle size distributions (PSDs), specifying the abundance or mass of particles for different size classes. The fragmentation model is coupled to an environmental box model, simulating the distributions of plastic particles in the ocean, coastal waters, and on the beach. We compare the modelled PSDs to available observations, and use the results to illustrate the effect of size-selective processes such as vertical mixing in the water column and resuspension of particles from the beach into coastal waters. The model quantifies the role of fragmentation on the marine plastic mass budget: while fragmentation is a major source of (secondary) plastic particles in terms of abundance, it seems to have a minor effect on the total mass of particles larger than 0.1 mm. Future comparison to observed PSD data allow us to understand size-selective plastic transport in the environment, and potentially inform us on plastic longevity.
