Deep-sea sediment disturbance may occur when collecting polymetallic nodules, resulting in the creation of plumes that could have a negative impact on the ecological environment. This study aims to investigate the potential solution of using polyaluminum chloride (PAC) in the water jet. The effects of PAC are examined through a self-designed simulation system for deep-sea polymetallic nodule collection and sediment samples from a potential deep-sea mining area. The experimental results showed that the optimal PAC dose was found to be 0.75 g/L. Compared with the test conditions without the addition of PAC, the presence of PAC leads to a reduction in volume, lower characteristic turbidity, smaller diffusion velocity, and shorter settling time of the plume. This indicates that PAC inhibits the entire development process of the plume. The addition of PAC leads to the flocculation of mm-sized particles, resulting in the formation of cm-sized flocs. The flocculation of particles decreases the rate of erosion on the seabed by around 30%. This reduction in erosion helps to decrease the formation of plumes. Additionally, when the size of suspended particles increases, it reduces the scale at which they diffuse. Furthermore, the settling velocity of flocs (around 10⁻² m/s) is much higher that of compared to sediment particles (around 10⁻⁵ m/s), which effectively reduces the amount of time the plume remains in suspension.

收集多金属结核时可能会发生深海沉积物扰动，从而产生羽流，对生态环境产生负面影响。本研究旨在探讨在水射流中使用聚合氯化铝（PAC）的潜在解决方案。通过自行设计的模拟系统对深海多金属结核采集和潜在深海矿区沉积物样品进行了检验，以检验 PAC 的效果。实验结果表明，最佳PAC投加量为0.75 g/L。与不添加PAC的测试条件相比，PAC的存在导致羽流体积减小、特征浊度降低、扩散速度更小、沉降时间更短。这表明PAC抑制了羽流的整个发育过程。 PAC的添加导致毫米尺寸的颗粒絮凝，从而形成厘米尺寸的絮凝物。颗粒的絮凝使海底侵蚀率降低了约 30%。侵蚀的减少有助于减少羽流的形成。此外，当悬浮颗粒的尺寸增加时，它们扩散的规模就会减小。此外，絮体的沉降速度（约10 ^-2 m/s）远高于沉积物颗粒（约10 ^-5 m/s），这有效地减少了羽流保持悬浮的时间。