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1.
The spatiotemporal distributions of dissolved and/or dispersed oil in seawater and pore water were monitored on site by fluorometric detection method after the Hebei Spirit oil spill. The oil concentrations in intertidal seawater, 15 days after the spill, were as high as 16,600 μg/L and appeared to decrease below the Korean marine water quality standard of 10 μg/L at most sites 10 months after the spill. Fluorometric detection of oil in pore water was introduced to eliminate the effects of grain size for the quantification of oil in sediments and to better explain spatial and temporal distribution of oil pollution at sandy beaches. The fluorescence detection method was compared with the conventional laboratory technique of total petroleum hydrocarbon analysis using gas chromatography. The method of fluorescence detection of oil was capable of generating results much faster and more cost-effectively than the traditional GC technique. 相似文献
2.
Sediment toxicity in silty marine harbor sediments is frequently dominated by ammonia or sulfide, leaving the adverse effects of persistent toxic substances unnoticed. To investigate the latter, we subjected interstitial water from three contaminated silty sediments to toxicity identification evaluation (TIE) phase I manipulations and tested for toxicity with four bioassays: the amphipod Corophium volutator (survival as an endpoint), the sea urchin Psammechinus miliaris (fertilization, embryo development) and the bacterium Vibrio fischeri (bioluminescence inhibition).The graduated pH manipulations identified the prominent toxicity of ammonia in the amphipod and sea urchin embryo tests, and also sulfide toxicity in the bacterium test. In two of the three samples tested with the amphipods, sea urchin embryos and bacteria, a small but significant reduction in interstitial water toxicity was achieved by removing persistent compounds through C(18) solid phase extraction. EDTA chelation resulted in a slight detoxification of the interstitial water for the amphipods and sea urchin embryos, but this was not related to any measured trace metals. Despite the presence of toxic levels of ammonia and sulfide in the harbor sediments, we established the adverse biological effects of persistent constituents by means of the TIE manipulations and in vivo interstitial water bioassays. 相似文献
3.
本文基于Biot动力固结理论和弹性动力学理论,考虑海床（土壤）的两相性、黏弹性人工边界及流（水）-固耦合作用,建立了隧道-土-流体相互作用的力学模型,讨论了P波作用下有无水的情况以及水深、水域隧道埋深、海床土性质和地震波入射角等因素对隧道及其周围海床应力的影响。结果表明:隧道周围海床土的孔隙水压力和隧道内应力随着水深的增加而增加;地震波特性和海床土特性对隧道的内应力和海床土的孔隙水压力均有较大的影响;海床土的渗透性和隧道埋深对隧道的内应力影响较小,而对隧道周围海床土的孔隙水压力影响较大;地震动的入射角对隧道的内应力和隧道附近土层的孔隙水压力均有较大影响。 相似文献
4.
Studies have been made of the effects of exposure to various forms of crude oil on the righting behaviour of Paracentrotus lividus and its reactions towards the presence of oil. Prolongation of the righting response was recorded in animals exposed to contact with surface or sunken fresh crude oil or to their water soluble fractions. No such effect was recorded on exposure to weathered oils and results indicate that the more volatile components of crude oil were responsible for this effect. Paracentrotus showed no avoidance reaction to the presence of sunken oil in its vicinity. The likely ecological significance of these results is discussed. 相似文献
5.
In the water flooding of mixed-wet porous media, oil may drain down to relatively low residual oil saturations (Sor). Various studies have indicated that such low saturations can only be reached when oil layers in pore corners are included in the pore-scale modelling. These processes within a macroscopic porous medium can be modelled at the pore-scale by incorporating the fundamental physics of capillary dominated displacement within idealised pore network models. Recently, the authors have developed thermodynamic criteria for oil layer existence in pores with non-uniform wettability which takes as input geometrically and topologically representative networks, to calculate realistic Sor values for mixed-wet and oil-wet sandstones [16, 21]. This previous work is developed in this paper to include (i) the visualisation of the 3D structure of this residual oil, and (ii) a statistical analysis of this “residual/remaining” oil. Both the visualisation and the statistical analysis are done under a wide range of wettability conditions, which is reported for the first time in this paper.The structure of residual oil for strongly water wet systems is well known (where residual = remaining oil) and our model agrees with this but this structure changes radically for mixed wet systems (where residual ≠ remaining) and this has not yet been visualised experimentally. We find that for more water-wet systems high final residual oil saturations are reached at relatively small amounts of water injected and this oil is present in the pores as bulk oil. On the other hand, for more oil-wet systems we find a slow decrease of the amount of remaining oil with increasing amounts of injected water. During the process, the remaining connectivity of the oil phase is increasingly provided by oil layers only, hence the slow drainage. The final residual oil saturation, only reached in the theoretical limit of an infinite amount of injected water, is almost entirely contained in large number of (relatively low volume) oil layers, which are present in pores of most radius sizes. 相似文献
6.
A.L. Bridi Th.H. Wanders W. Zegveld H.B. van der Heijde 《Marine pollution bulletin》1980,11(12):343-348
During the combatting of oil spills, the handling of the stable sea water in crude oil emulsions called ‘chocolate mousses’, either at sea or on the beach, is often a major problem.
A recent laboratory study of the formation and properties of such emulsions revealed the key roles played by asphaltenes and crystallized wax in their stability.
Viscosity measurements showed that mousses with 70% vol. sea water are thixotropic and may solidify after having been pumped into the hold of a salvage vessel or into a storage tank. During a search for novel chemicals for combatting oil spills we found a type of chemical additive that is effective in preventing the formation of mousses, in greatly improving the pumpability of mousses once formed and in decreasing their water content after recovery or during storage. The additive, designated LA 1834, has been tested successfully in the laboratory, on a semi-technical scale in cooperation with the Netherlands State Waterways Board and in the large-scale clean-up operation after a recent oil spill in Greece. The compound keeps oil from dispersing vertically into the water column, when applied to spilled oil or mousse on a sea water surface and holds promise of environmental acceptability. 相似文献
7.
Gerard P. Canevari 《Marine pollution bulletin》1982,13(2):49-54
The formation of stable sea water-in-crude oil emulsions after an oil spill was first reported after the Torrey Canyon wreck in 1967. The problem of handling this stable water (65%)-in-oil (35%) emulsion rather than oil is evidenced in the additional expensive on-site storage requirement as well as the handling difficulty with the viscous semi-solid emulsion. This paper details the results of an R&D program that has established the mechanism for the formation of this emulsion. This insight enabled a specific effective chemical demulsifier to be formulated. A treatment technique was devised that entails injecting the demulsifier into the oil spill emulsion as it is skimmed from the water surface. The emulsion is then rapidly separated into water-free oil and a clean-water phase that can be decanted back into the sea. Full-scale tests were successfully conducted by JBF Scientific Corp. using two types of commercial JBF DIP skimmers in a small concrete lined pond. 相似文献
8.
Salsvatn,a lake with old sea water 总被引：1，自引：0，他引：1
Dr. Anders Bøyum 《Aquatic Sciences - Research Across Boundaries》1973,35(2):262-277
Salsvatn is a 464 m deep lake laying 16 m above sea level in North Trøndelag, Norway. The lake was isolated from the sea some 3,000 years ago. It is assumed that salt-water in the deepest 50 m of the lake is the remain of sea water being trapped in the lake at this time. The concentration of cloride in the salt-water layer corresponds to a salinity of 29‰ in ordinary sea water. Hydrography of the lake and changes in some components of the salt water compared with ordinary sea water are discussed. Comparison is made with changes in the stagnant layers of the Black Sea and Lake Rørholtjorden. The latest is another lake with old sea-water at its bottom. Surface sediment samples have been collected from the freshwater and salt-water layers in Lake Rørholtfjorden and from the salt-water layer of Lake Salsvatn. Some chemical components of the sediments and interstitial water have been analysed and discussed. 相似文献
9.
中国西部某盆地致密油储层孔隙结构差,而核磁共振测井T2谱宽,其复杂的核磁测井响应认识不清,且响应机理也不明确.本文基于致密油储层的特性,通过对三组岩样不同系列的实验测量,包括核磁共振、毛管压力曲线、X衍射矿物分析和润湿性实验,主要研究了碳酸盐岩矿物含量对T2谱的影响和由润湿性引起的T2弛豫机制.根据实验结果分析和讨论,明确了致密油岩石核磁共振响应的影响因素及孔隙流体的弛豫机制.综合分析认为,所述的核磁测井响应特征是由两方面因素综合作用的结果,一是水的T2信号主要取决于表面弛豫,低表面弛豫率的碳酸盐岩矿物导致水的T2信号的长弛豫分量增多;二是由于岩石亲油孔隙表面的存在且其弛豫率低于亲水孔隙表面的弛豫率,使得油的T2信号由表面弛豫和体弛豫贡献. 相似文献
10.
Mary K. Wicksten 《Marine pollution bulletin》1984,15(1):28-33
Sea anemones (Anthopleura elegantissima) can withstand submersion in Bunker C fuel oil for up to 1 h without visible adverse effects. The wet, mucus-covered tissues of the sea anemones may repel oil. During recovery, the sea anemones expand the column, evert the tentacles and reattach. A dahlia anemone (Tealia lofotensis) withstood immersion in oil for 15 min. The ability to withstand immersion in oil may confer an ecological advantage to sea anemones in contaminated areas. 相似文献
11.
12.
The effects of oil pollution on the sea anemone Actinia equina were investigated. Chronic pollution with 2.5 ml.l?1 crude oil resulted, for about seven weeks, in ejection of increased numbers of the young which are normally brooded within the gastric cavity. Subsequently the numbers of surviving young being produced fell to zero, and the ovaries were found to be regressed and lacking ova. The anemones were also more frequently observed with tentacles expanded and mouth open, but the response to food offered to the tentacles was slow or absent. In separate tests it was found that crude oil presented on filter paper to the anemones could act as a feeding inducer, but that it interfered with or diluted the action of natural feeding inducers present in fish muscle extract. These effects are comparable with those which oil pollution has been found by other workers to have upon other anthozoans—the corals. 相似文献
13.
Pore water testing and analysis: the good,the bad,and the ugly 总被引：8，自引：0，他引：8
The increasingly common practice of collecting and assessing sediment pore water as a primary measure of sediment quality is reviewed. Good features of this practice include: pore water is a key exposure route for some organisms associated with sediments; pore water testing eliminates particle size effects; pore water analyses and tests can provide useful information regarding contamination and pollution. Bad features include: pore water is not the only exposure route; pore water tests lack chemical or biological realism: their "sensitivity" relative to other tests may be meaningless due to manipulation and laboratory artifacts; many sediment and surface dwelling organisms are not directly influenced by pore water. Bad features can become ugly if: other exposure pathways are not considered (for toxicity or bioaccumulation); manipulation techniques are not appropriate; pore water tests are inappropriately linked to population-level effects. Pore water testing and analyses can be effective tools provided their limitations are well understood by researchers and managers. 相似文献
14.
利用特征函数展开方法，给出了基于扩散效应的核磁共振Bloch控制方程的弛豫模式解表达式, 在此基础上分别给出了水饱和与油水双相饱和孔隙模型的核磁共振特性模拟结果. 结果表明，孔隙流体的核磁弛豫与孔隙大小、孔隙表面弛豫率、孔隙流体的扩散能力以及含油饱和度等有密切的关系. 对于水饱和孔隙，弛豫时间主要由孔隙大小控制. 当孔隙较大时，即使均匀大小孔隙，孔隙流体的弛豫也会表现为多指数弛豫. 而且最小模式弛豫时间与孔隙大小为非线性关系. 对于油水双相饱和孔隙，在孔隙较小时，含油饱和度对弛豫的影响主要表现在弛豫时间随含油饱和度的增加而线性减小；但在孔隙较大时，含油饱和度的增加对弛豫影响表现在两个方面，其一，孔隙水弛豫由多个弛豫模式控制逐渐转变为由最小弛豫模式控制；其二，孔隙水弛豫时间与含油饱和度表现为非线性关系. 对由实际岩芯抽象出的孔隙模型，采用本文获得的理论公式，在油水双相饱和时进行了正反演模拟. 计算结果与已有的实验结果较为一致. 相似文献
15.
The fate and effects of the spill of Eleni V heavy fuel oil in May 1978 have been followed at two sites; one a heavily-polluted area subject to mechanical clean-up and one an undisturbed site where oil remains. At the first site the mechanized clean-up, and re-sorting of beach material by winter storms, has left the area visually clean of oil. However, near-shore and interstitial waters still contain high concentrations of Eleni V hydrocarbons 12 months after the spill. At the undisturbed site there has been very little change in the appearance and chemical composition of the oil during this period. 相似文献
16.
Mark A. Ricca A. Keith Miles James L. Bodkin Kimberly A. Trust 《Marine pollution bulletin》2010,60(6):861-872
Exposure to contaminants other than petroleum hydrocarbons could confound interpretation of Exxon Valdez oil spill effects on biota at Prince William Sound, Alaska. Hence, we investigated polychlorinated biphenyls (PCBs) in blood of sea otters and harlequin ducks sampled during 1998. PCB concentrations characterized by lower chlorinated congeners were highest in sea otters from the unoiled area, whereas concentrations were similar among harlequin ducks from the oiled and unoiled area. Blood enzymes often elevated by xenobiotics were not related to PCB concentrations in sea otters. Only sea otters from the unoiled area had estimated risk from PCBs, and PCB composition or concentrations did not correspond to reported lower measures of population performance in sea otters or harlequin ducks from the oiled area. PCBs probably did not influence limited sea otter or harlequin duck recovery in the oiled area a decade after the spill. 相似文献
17.
We present a semi-analytical, combinatorial approach to compute three-phase capillary entry pressures for gas invasion into pore throats with constant cross-sections of arbitrary shapes that are occupied by oil and/or water. For a specific set of three-phase capillary pressures, geometrically allowed gas/oil, oil/water and gas/water arc menisci are determined by moving two circles in opposite directions along the pore/solid boundary for each fluid pair such that the contact angle is defined at the front circular arcs. Intersections of the two circles determine the geometrically allowed arc menisci for each fluid pair. The resulting interfaces are combined systematically to allow for all geometrically possible three-phase configuration changes. The three-phase extension of the Mayer and Stowe – Princen method is adopted to calculate capillary entry pressures for all determined configuration candidates, from which the most favorable gas invasion configuration is determined. The model is validated by comparing computed three-phase capillary entry pressures and corresponding fluid configurations with analytical solutions in idealized triangular star-shaped pores. It is demonstrated that the model accounts for all scenarios that have been analyzed previously in these shapes. Finally, three-phase capillary entry pressures and associated fluid configurations are computed in throat cross-sections extracted from segmented SEM images of Bentheim sandstone. The computed gas/oil capillary entry pressures account for the expected dependence of oil/water capillary pressure in spreading and non-spreading fluid systems at the considered wetting conditions. Because these geometries are irregular and include constrictions, we introduce three-phase displacements that have not been identified previously in pore-network models that are based on idealized pore shapes. However, in the limited number of pore geometries considered in this work, we find that the favorable displacements are not generically different from those already encountered in network models previously, except that the size and shape of oil layers that are surrounded by gas and water are described more realistically. The significance of the results for describing oil connectivity in porous media accurately can only be evaluated by including throats with more complex cross-sections in three-phase pore-network models. 相似文献
18.
WU HeYong LIANG XiaoDong XIANG CaiFu & WANG YueWen Daqing Oil Field Exploration Development Research Institute Daqing China Institute of Geology Geophysics Chinese Academy of Sciences Beijing China Basin & Reservoir Research Center of China University of Petroleum Beijing China 《中国科学D辑(英文版)》2007,50(5):702-709
The relation between oil and water in reservoirs with low and ultra-low permeability is very complicated. Gravitational separation of oil and water is not obvious. Normal reservoirs are located in depression and structural high spot, oil and water transitions are located in their middle. Stagnation is the key fact of oil-forming reservoir in the axis of a syncline based on the research of oil, gas and water migration manner, dynamics and non-Darcy flow in the Songliao basin. In low and ultra-low permeable reservoir, gas and water migrate easily through pore throats because their molecules are generally smaller than the pore throats; but the minimum diameter of oil droplets is larger than pore throats and they must be deformed to go through. Thus, gas and water migrate in advance of oil, and oil droplets remain behind. Pressure differential and the buoyancy force in a syncline reservoir are a main fluid driving force; and capillary force is the main resistance to flow. When the dynamics force is less than resistance, oil is immobile. When the buoyancy force is less than the capillary force, a gravitational separation of oil and water does not occur. The reservoir in the mature source rock of a syncline area with the low and ul- tra-low permeability belongs to an unconventional petroleum reservoir. 相似文献
19.
A biological oil adsorption filter 总被引：4，自引：0，他引：4
Pasila A 《Marine pollution bulletin》2004,49(11-12):1006-1012
A new oil adsorption method called adsorption filtration (AF) has been developed. It is a technology where by oil residues can be cleaned from water by running it through a simple filter made from freeze treated, dried, milled and then fragmented plant material. By choosing suitable plants and fragmentation sizes it is possible to produce filters, which pass water but adsorb oil. The aim of this study was to investigate the possibilities of manufacturing oil adsorbing filter materials from reed canary grass (Phalaris arundinacea), flax (Linum usitatissimum L.) or hemp fibre (Cannabis sativa L.). The oil (80 ml) was mixed with de-ionised water (200 ml) and this mixture was filtered through 10 or 20 g adsorption filters. Fine spring harvested hemp fibre (diameter less than 1 mm) and reed canary grass fragments adsorb 2-4 g of oil per gram of adsorption material compared to 1-3 g of water. Adsorption filtration is thus a novel way of gathering spilled oil in shallow coastal waters before the oil reaches the shore. 相似文献
20.
A novel semi-analytical model for computation of capillary entry pressures and associated fluid configurations in arbitrary, potentially non-convex, 2D pore space geometries at uniform wettability is developed. The model computes all possible centre positions of circular arcs, and physically sound criteria are implemented to determine the set of these arcs that correspond to geometrically allowed interfaces. Interfaces and pore boundary segments are connected to form closed boundaries of identified geometrical regions. These regions are classified as either oil regions, located in the wider parts of the pore space, or as water regions located in pore space constrictions. All possible region combinations are identified and evaluated for each radius value in an iterative procedure to determine the favourable entry radius and corresponding configuration based on minimisation of free energy. The model has been validated by comparison with known analytical solutions in idealised pore geometries. In cases where different analytical solutions are geometrically possible, the model generates several oil and water regions, and the valid solution is determined by the region combination that corresponds to the most favourable entry pressure, consistent with the analytical solution. Entry pressure radii and configurations are computed in strongly non-convex pore spaces extracted from an image of Bentheimer sandstone, which demonstrates that the model captures successfully well-known characteristics of capillary behaviour at different wetting conditions. The computations also demonstrate the importance of selecting the fluid configuration of minimum change in free energy. In some cases, a merged region formed by a combination of oil and water regions corresponds to the favourable entry configuration of oil, whereas in other cases, an individual oil region may correspond to the favourable oil entry configuration. It is also demonstrated that oil entry configurations may constitute merged regions for weakly water-wet conditions and individual oil regions for strongly water-wet conditions in the same pore space. The computations show that the ratio of pore area to perimeter multiplied by the cosine of the contact angle under-predicts the entry pressure radii in Bentheimer sandstone pore spaces. An alternative formula is proposed for prediction of entry radii for nonzero contact angles based on the entry radii obtained for zero contact angles. 相似文献