Application of in situ dialysis cultures in studies of phytotoxicity of north sea crude oils

The three marine planktonic diatoms Skeletonema costatum (clone Skel-5), Thalassiosira pseudonana (clone 3H) and Phaeodactylum tricornutum (clone Pheo) were grown in dialysis cultures in outdoor tanks exposed to seawater extracts of Ekofisk and Statfjord crude oils and to sea water collected below an artificial oil spill with Statfjord crude oil at Haltenbanken.The effects on growth rate and photosynthetic capacity were similar to those observed in laboratory batch cultures, and so was the difference in sensitivity among the algae, with Skeletonema being the most sensitive species.The in situ dialysis culture technique served well as a link between the laboratory and the field situations, and may be used as a monitor of phytotoxic effects in an oil spill situation.     

Assessing the effects of the Prestige oil spill on the European shag (Phalacrocorax aristotelis): trace elements and stable isotopes

The Prestige oil spill resulted in the mortality of several seabird species on the Atlantic NW coast of Spain. Shag casualties were particularly relevant, since populations are resident in the area the whole year round and because of several features which make them highly vulnerable to environmental hazards. Ecological catastrophes give us the opportunity of collecting samples which, otherwise, would be difficult to obtain. We examine the potential of shag corpses as bioindicators of inorganic pollution and the possible factors of variability, such as biological traits (sex, age) or nutrition status. We determined trace elements (Hg, Se, Cr, Pb, Zn and Cu) and isotopic signatures (¹⁵N, ¹³C) in soft tissues (muscle, liver) and in primary feathers formed at different times (before and after the Prestige) in individuals of known sex and age, collected at the time of the Prestige disaster. These were compared with data from another group of shags trapped accidentally in fishing gear in 2005.Our results did not seem to be affected by sex or age on any of the analysed variables. The higher nitrogen isotopic signatures in the soft tissues of the Prestige shags may be related to the nutrition stress caused by a poorer body condition, which is also reflected in increasing levels of some metals in the liver. This isotopic enrichment was also observed in newly forming feathers when compared to the old ones. On the other hand, the lower δ¹⁵N and Hg values in shag feathers from 2005 point to a shift in feeding resources to prey of lower trophic levels. We found that feather features (being an inert tissue and having a conservative composition), if combined with careful dating and chemical analysis, offer a very useful tool to evaluate temporal and spatial changes in seabird ecology in relation to pollution events.     

Investigation on mechanical exhaust of cabin fire in large-space building

A calculation model for mechanical exhaust rate in large-space building in the case of cabin fire is proposed through theoretical analysis. Full-scale hot smoke tests are then performed to study the cabin fire spreading to large-space building at different air change rates (ACH). The result indicates that under the standard prescribed ACH, the effective air heights in the large spaces are respectively 6, 4 and 2 m in the case of cabin fires of 0.34, 0.67 and 1 MW. Numerical experiment has been conducted using self-developing two-zone model. The smoke control efficiency is compared by varying the large space’s air change rate in the case of cabin fires ranging from 0.25 to 4 MW. The calculation results show that the air change rates are respectively 3, 6, 10 and 10 ACH when the smoke layer is kept above 5 m, indicating that the centralized exhaust rates far exceed the standard prescribed value. To address this problem, a set of subsidiary distributed mechanical exhaust installing in the cabin with high fire loads is proposed. The simulation shows that both from the safety and economy point of view, the adoption of subsidiary distributed cabin exhaust design may effectively reduce the demand of designed air change rate for large-space building. Supported partially by the National Natural Science Foundation of China (Grant Nos. 50674079 and 50579100)     

Limitations of the Swedish network coordination of oil spill preparedness

The management of extreme crisis situations in Sweden has shown delays in decisive actions at higher levels during emergencies, such as oil spills. This has been blamed on unclear responsibilities that undermine the decision‐making process. Confusing, conflicting, or delayed orders impede response effectiveness. This article uses network analysis and survey responses to examine the Swedish oil spill crisis management network and show the Swedish Coast Guard, Swedish Agency for Marine and Water Management, Swedish Civil Contingencies Agency and Oil Spill Advisory Service as central organizations. However, the roles of these organizations need to be clarified and communicated better to other organizations. In order to improve coordination of Swedish oil spill preparedness, it is suggested to formalize and strengthen the roles of these central organizations. Weak connections between municipalities in different counties were also observed. This weakness could be overcome by more frequent exercises across counties to improve familiarity.     

闽江航道建设对下游敏感目标溢油风险预测

溢油事故是不可逆的环境污染事故,会破坏水体水质,危害生态系统,因而溢油事故的危害不容小觑。闽江下游有多个取水口及湿地保护区,闽江航道施工期及运营期均有溢油事故发生的风险,可能会对环境敏感目标造成影响。根据工程区域情况以及工程建设要求,以二维非稳态模型为平台,建立闽江下游水动力模型,基于实测资料进行模型可靠性分析。在准确的水动力模型基础上,以"油粒子"跟踪技术为指导,建立闽江航道溢油风险预测模型,对闽江下游航道建设施工期及运营期最不利条件下的溢油事故风险进行预测研究,可为闽江应急事故处置、溢油损害评价及取水口的安全管理提供支持和帮助。所提出的溢油事故风险预测方法及思路,能够对溢油事故的积极预防提供一定的参考依据。     

基于卫星遥感图像的变化检测算法

在石油勘探、开发炼制及运储过程中,由于意外事故或操作失误,造成原油或油品从作业现场储器里外泄,溢流向地面、水面、海滩或海面,同时由于油质的不同,形成薄厚等一片膜这现象称为溢油.大范围的海上溢油往往会对数个国家的生态、社会以及经济带来严重影响.本文基于卫星遥感数据,将变化检测引入海上溢油的问题中,研究实现对比了多个变化检测算法,最终实现了一个变化检测的溢油检测系统.实验表明,变化检测能有效地减少因地理位置、光照条件因素的影响,泛化能力显著地强于单幅图的分类方法,文章提供的系统能有效地将油区与水面、轻油区域与重油区域分割.     

基于LIF海面溢油平坦厚油膜区域边缘厚度评估方法研究

油膜厚度是对海面溢油污染定量分析的一个重要指标。结合海面溢油平坦和非平坦两种厚油膜区域的形态特点,依据激光诱导荧光(LIF)技术探测不同厚度油膜的信号特征给出判定,提出平坦厚油膜区域边缘厚度评估方法,根据油膜区域边缘厚度的不同,采用荧光强度估算油膜厚度。实验观察平坦厚油膜边缘的厚度变化,利用LIF实验系统对平坦厚油膜的边缘厚度进行评估,结果表明,该方法对于厚度大于20μm的油膜厚度评估,相对偏差在±10%左右。     

中海油惠州炼化二期项目事故状态下事故水环境污染及海上溢油风险应对措施综述

中海惠州炼化二期项目是国内最大的炼化一体化项目之一,在生产过程中实现环境友好,保证环境不受污染,不仅是企业的经济责任还足企业应尽的社会责任。文章重点论述了在事故应急状态下,惠州炼化二期项目在陆域采取的“置级防控措施”,码头采取的应急关断措施,海上溢油采取的“三级布控措施”,有效控制事故状态下事故水的流向,避免事故水外溢．污染环境：针对海上溢油的突发事件,通过三级布控,有效的资源配置,及时控制溢油所造成的海上污染。通过本文的论述,不但对即将建设的中海惠州炼化二期项目的建设有积极作用,对其他濒海的石化企业避免事故水环境污染及海上溢油应急处理也有指导意义。