Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education/Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266100, PR China.
Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education/Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266100, PR China.
Chemosphere. 2021 Oct;281:130744. doi: 10.1016/j.chemosphere.2021.130744. Epub 2021 May 12.
The employment of dispersant was an effective method to treat marine oil spill pollution. However, conventional dispersants only showed a single oil dispersion. Here, by modifying TiO nanoparticles with biosurfactant-Rhamnolipids (Rha), a highly efficient particulate dispersant with photocatalytic activity was developed. Rha-TiO showed both excellent oil spill dispersion and facilitated photodegradation for oil simultaneously. The oil droplets dispersed by Rha-TiO in seawater exhibited long time stability, which indicated the synergistic emulsification interactions between TiO and Rha in artificial sea water (ASW). The dispersion mechanism of Rha-TiO was analyzed, we found the TiO nanoparticles alone weren't effectively emulsified oil in high salinity ASW, but the addition of a small amount of Rha could modify the surface wettability of TiO nanoparticles to form the stable emulsion. In addition, the addition of a small amount of Rha could reduce the surface tension of the oil-water interface, which contribute to increasing the content of TiO nanoparticles at the oil-water interface, form a steric rigid layer around the oil droplets to prevent droplet coalescence and facilitate the further photocatalytic degradation of oil. In short, the Rha-TiO nanoparticles could effective disperse oil in ASW, meanwhile the TiO also played the role of photocatalytic degradation of oil pollution. Hence, this study developed a novel photocatalytic particulate dispersant to remediate marine oil spill and delivered a new feasible solution for practical oil spill treatment in the future.
使用分散剂是处理海洋溢油污染的一种有效方法。然而，传统的分散剂仅表现出单一的油分散作用。在这里，通过用生物表面活性剂鼠李糖脂（Rha）修饰 TiO 纳米粒子，开发了一种具有光催化活性的高效颗粒分散剂。Rha-TiO 同时表现出优异的溢油分散性和促进油的光降解作用。在海水中分散的 Rha-TiO 油滴表现出长时间的稳定性，这表明 TiO 和 Rha 之间在人工海水中（ASW）具有协同乳化相互作用。分析了 Rha-TiO 的分散机制，我们发现 TiO 纳米粒子本身在高盐度 ASW 中不能有效地乳化油，但少量 Rha 的添加可以改变 TiO 纳米粒子的表面润湿性，形成稳定的乳液。此外，少量 Rha 的添加可以降低油水界面的表面张力，从而有助于增加油水界面处 TiO 纳米粒子的含量，在油滴周围形成刚性的空间位阻层，防止液滴聚并，并促进油的进一步光催化降解。总之，Rha-TiO 纳米粒子可以有效地在 ASW 中分散油，同时 TiO 也起到了光催化降解油污染的作用。因此，本研究开发了一种新型的光催化颗粒分散剂来修复海洋溢油，并为未来实际溢油处理提供了一种新的可行方案。
