滨海环境石油-悬浮颗粒物凝聚及其清除溢油机制研究

With the increasing demands of the crude oil and products and the marine transportation, oil spill accidents frequently occur. When oil spill occurs in the coastal environment, the spilled oil may interact with the suspended particulate matter (SPM) in the water column to form oil-SPM aggregates (OSAs). This process has been recognized to enhance the natural cleansing of oiled shorelines. In this study, batch scale experiments are designed and conducted to understand the dispersion characteristics of the spilled oil and the following formation and characteristics of OSAs under different mixing conditions. On the basis of the batch scale experiments, large wave tank experiments are then designed and conducted to investigate the remediation rate and transfer routes of the spilled oil when OSAs form in the water column under the influence of different environmental factors with the existence of high efficient oil degradation microorganism and chemical dispersant. This study is designed based on the formation and remediation theory of the water pollution and theory of the environmental forensics. The experiments are conducted using different suspended particulate matter samples and seawater sample collected from the large scale off-shore oil and natural gas field located in Laizhou Bay and areas of Jiaozhou Bay where oil spills frequently occur. Most frequently spilled oil products，suspended particulate matter with different components in those areas are selected for the indoor simulation experiments. The influence of physiochemical properties of oil (density, viscosity, interfacial tension, and polar components), SPM (hydrophilicity, mineral components, microorganism and plankton components), and seawater (salinity, temperature and mixing energy) on the remediation rates of spilled oil are studied. The mathematical expression between the properties of the oil-solid-water system and the oil remediation rate is developed. Gas Chromatograph equipped with flame ionization detector, the environmental scanning electron microscope and the image digital processing software based on Matlab are used as the main analysis methods. Mechanisms of oil-suspended particulate matter aggregation and the spilled oil removal are then determined based on the fitting analysis to the large number of data sets. The results may provide scientific basis and technology guidance to the development of a more efficient, environmental friendly and reasonable oil spill remediation strategy.

随着全球对石油产品需求和石油海洋运输的增加，海洋溢油事故频繁发生。一旦发生溢油事故需要及时有效地清除溢油。在悬浮物含量较高的近海区域由于溢油和悬浮颗粒凝聚会增大溢油的扩散和降解，从而有利于溢油的自然清除。本课题针对莱州湾海上油气田以及胶州湾溢油易发区的水文地质条件，采集代表性的近海悬浮颗粒物、易泄漏油品和海水样品，在系统测定各试验样品组成和物理化学性质的基础上，采用室内批量试验研究悬浮颗粒物-油-水复杂体系中油-水界面特征及其与石油-悬浮颗粒物凝聚的内在关系，研究近岸水化学及水动力作用条件下悬浮颗粒物对溢油的分散特征和微生物降解规律的影响，并通过室内波浪槽模拟试验及大量数值拟合探索近岸复杂水化学及水动力条件下，不同悬浮颗粒物及其与高效石油降解微生物菌剂或溢油分散剂共存条件下石油-悬浮颗粒物凝聚体的形成规律和溢油迁移路径，为添加颗粒物作为一种高效、环境友好型溢油修复新技术提供科学依据。

随着全球对石油产品需求和石油海洋运输的增加，海洋溢油事故频繁发生。一旦发生溢油事故需要及时有效地清除溢油。在悬浮物含量较高的近海区域由于溢油和悬浮颗粒凝聚会增大溢油的扩散和降解，从而有利于溢油的自然清除。本课题针对莱州湾以及胶州湾溢油易发区的水文地质条件，采集代表性的近海悬浮颗粒物、易泄漏油品和海水样品，在系统测定各试验样品组成和物理化学性质的基础上，采用室内批量试验研究悬浮颗粒物-油-水复杂体系中油-水界面特征及其与石油-悬浮颗粒物凝聚的内在关系，以及不同悬浮颗粒物及其与高效石油降解微生物菌剂或溢油分散剂共存条件下石油-悬浮颗粒物凝聚体的形成规律和溢油迁移路径。研究筛选出高效清除海洋溢油的微生物菌剂，可通过产表面活性剂和石油降解双重作用清除溢油。将筛选出的天然颗粒物进行有机改性和插层，考察天然及改性颗粒物对于油水界面性质和降解特征的影响。改性颗粒物条件下油水界面张力和Zeta电位绝对值均小于天然颗粒物条件，凝聚体形成效率高于天然颗粒物条件。加入天然土、皂土和高岭土，可使溢油的微生物降解率分别提高6%，9%和12%。改性颗粒物由于亲油性增强，对于烷烃重质组分和芳香烃组分的结合明显升高。随着颗粒物浓度增加和颗粒物粒径的减小，油水界面张力和Zeta电位的绝对值均减小，凝聚体形成率增加，溢油微生物降解率增加。加入微生物颗粒，对于油水界面张力和Zeta电位具有相似的影响。盐度在0~5‰之间时，基本没有凝聚体的形成，溢油的微生物清除效率过低；随着风化的进行凝聚体形成率逐渐降低，颗粒物对溢油降解率的影响降低，凝聚体和油滴粒径最大分别可达41和25 µm；消油剂可使分散油滴粒径变小，凝聚体和油滴粒径最小分别可达14和2 µm，适量消油剂会促进溢油的微生物降解率，但是当剂油比超过0.2时溢油生物降解率降低。