Song Xing, Jing Liang, Chen Bing, Zhu Zhiwen, Cai Qinhong, Ye Xudong, Zheng Xiao, Hill Stephen J, Zhang Baiyu
Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, NL A1B 3X5, Canada.
Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada.
Heliyon. 2021 Mar 11;7(3):e06291. doi: 10.1016/j.heliyon.2021.e06291. eCollection 2021 Mar.
Droplet size distribution of dispersed oil in deep-water is critical to the transport and biodegradation of spilled oil in deep-sea. Few studies have focused on the effects of pressure on chemically dispersed oil through experiments. This study thus simulated how the crude oil homogenously pre-dispersed by Corexit 9500A using baffled flasks would behave after being exposed to deep-water conditions. Key factors included dispersant-to-oil ratio (DOR), mixing energy (energy dissipation rate and Kolmogorov microscale), and pressure (up to 150 bar). The variations of pressure were demonstrated to have insignificant effects on the size distribution of pre-dispersed oil. Both the average and medium droplet sizes were correlated negatively with DOR and mixing energy in an established model with a p-value ≤ 0.0011. The log-normal and log-logistic distributions provided a reasonable fit to simulate the droplet size distribution. The two parameters of log-logistic distribution were dependent on DOR and mixing energy with a p-value < 0.005. The results would be valuable to advance the understanding of the behaviours and trajectories of chemically dispersed oil under deep-water conditions. The research helped provide more scientific evidence to improve the understanding of dispersed oil behaviours under high pressure and support deep-sea oil spill research and potential extension of the existing results from shallow water to deep water conditions.
深水环境中分散油滴的粒径分布对于深海溢油的输运和生物降解至关重要。很少有研究通过实验关注压力对化学分散油的影响。因此，本研究模拟了使用折流板烧瓶用Corexit 9500A均匀预分散的原油在暴露于深水条件后的行为。关键因素包括分散剂与油的比例（DOR）、混合能量（能量耗散率和科尔莫戈罗夫微尺度）以及压力（高达150巴）。结果表明，压力变化对预分散油的粒径分布影响不显著。在一个p值≤0.0011的既定模型中，平均液滴尺寸和中值液滴尺寸均与DOR和混合能量呈负相关。对数正态分布和对数逻辑分布能够合理地拟合模拟液滴粒径分布。对数逻辑分布的两个参数取决于DOR和混合能量，p值<0.005。这些结果对于增进对深水条件下化学分散油的行为和轨迹的理解具有重要价值。该研究有助于提供更多科学证据，以加深对高压下分散油行为的理解，并支持深海溢油研究以及将现有浅水结果潜在扩展到深水条件。
