A simple stochastic numerical model is applied to obtain the distribution of the terminal settling/rising velocity of a set of MPs particles whose size, shape, and density have their distributions in accordance with field observations and production trends. Results of the direct Monte Carlo simulation are shown to reproduce well the data of laboratory experiments. Distributions of MPs by size and density appear to be more valuable for the final terminal velocity distribution compared to the influence of the distribution by shape. The most “real” of the simulated distributions of the terminal velocity of MPs particles in the ocean has a multimodal shape, slightly different for fresh and saline waters. Multimodality arises from the fact that the terminal velocity depends on several physical parameters simultaneously and thus should be an expected feature of MPs terminal velocity distribution.

应用简单的随机数值模型来获得一组MPs粒子的最终沉降/上升速度的分布，这些MPs粒子的大小，形状和密度根据现场观察和生产趋势而具有其分布。直接蒙特卡罗模拟的结果显示可以很好地复制实验室实验的数据。相较于形状分布，MP的尺寸和密度分布对于最终的最终速度分布似乎更有价值。海洋中MPs颗粒终末速度的最“真实”模拟分布具有多峰形，对于淡水和咸水略有不同。