From the viewpoint of improving the visibility of water in small lakes and ponds, in a previous study, we treated turbidity-causing (TC) particles and adsorption agents. Brownian dynamics simulations were conducted for particles with a spherical shape in order to elucidate the adsorption performance of the agents in the gravitational field. The technique for the adsorption is based on the use of the translational Brownian motion of the adsorption particles. If non-spherical particles are used as adsorption agents, then rotational Brownian motion is also expected to make a significant contribution to the adsorption performance. In the present study, we have employed the modeling of large spherocylinder adsorption particles and small spherical TC particles with sub-micron size, in order to perform Brownian dynamics simulations in regard to adsorption and sedimentation in the gravitational field. For the case of adsorption particles with a low aspect ratio, the adsorption rate is not significantly different to the spherical particle case, with an improvement of only a few percent. This implies that the rotational Brownian motion hardly contributes to the adsorption performance. In contrast, for the case of a rod-like particle with a high aspect ratio, the adsorption rate is much better than that for the spherical particles, with an improvement of around 75%, and therefore it is seen that the effect of the rotational Brownian motion gives rise to a much more significant adsorption performance. This is mainly because with an increasing aspect ratio the opportunity for the agent particles to contact with the TC particles increases more significantly due to the effect of the rotational Brownian motion. From these results, we understand that rod-like particles with a high aspect ratio employed as adsorption agents are able to adsorb TC substances much more efficiently in comparison to spherical particles.

中文翻译：

---

布朗动力学模拟中球形和棒状颗粒在重力场中的沉积特征：用于改善小湖泊和池塘的能见度

从提高小湖泊和池塘中水的能见度的角度出发，在先前的研究中，我们处理了导致浑浊的颗粒（TC）和吸附剂。对球形颗粒进行了布朗动力学模拟，以阐明试剂在重力场中的吸附性能。吸附技术基于吸附颗粒的平移布朗运动的使用。如果将非球形颗粒用作吸附剂，则还期望旋转布朗运动对吸附性能做出重大贡献。在本研究中，我们采用了大球形圆柱体吸附颗粒和亚微米尺寸的小球形TC颗粒的模型，为了对重力场中的吸附和沉降进行布朗动力学模拟。对于长径比低的吸附颗粒，其吸附速率与球形颗粒的吸附速率没有显着差异，仅提高了百分之几。这意味着旋转布朗运动几乎不影响吸附性能。相反，对于长径比高的棒状颗粒，其吸附速率比球形颗粒的吸附速率好得多，提高了约75％，因此可以看出旋转效应布朗运动引起显着得多的吸附性能。这主要是因为随着纵横比的增加，由于旋转布朗运动的作用，试剂颗粒与TC颗粒接触的机会大大增加。根据这些结果，可以理解，与球形颗粒相比，具有高纵横比的棒状颗粒用作吸附剂能够更有效地吸附TC物质。