Modeling the fate and transport of Al-Ahmadi oil spill

Over the period January-May 1991 Iraqi forces, occupying the state of Kuwait, caused a massive amount of oil to be released in the waters of the Arabian Gulf. The volume of oil released may have been as large as 6 × 10⁶ bbls. Most of the oil was released at or near Mina Al-Ahmadi in southern Kuwait. Two mathematical models, GULFSLIK II and OILPOL, were used to simulate the fate and transport of oil spilled at Al-Ahmadi. The oil spill trajectory model GULFSLIK II was used in an operational real time mode to predict the surface trajectory of oil spills at various locations. The real time trajectory analysis was used to support tactical spill response. Short term precictions were made using 7-d wind forecasts. Long term predictions were made using monthly wind averages. Comparisons between predicted trajectories and actual sightings show that GULFSLIK II is reasonably accurate. The oil spill fate and transport model, OILPOL, was applied to compute surface and subsurface distribution of oil, and analyze the fate of the spilled oil. An oil spill size of 4 × 10⁶ bbls was assumed. OILPOLL results were used to support damage assessment studies and environmental impact statements. The distribution of oil on the surface and subsurface layers were obtained daily for a period of 80 d. Oil concentration at strategic locations in the Gulf were also computed. Surface oil distribution as predicted by OILPOL was compared with sighting data. The results show excellent agreement.     

Numerical simulation of the movement of the 1991 oil spills in the Arabian Gulf

The output from the modified version of a hydrodynamical numerical model developped earlier by El-Sabh and Murty (1988) has been used to hindcast the movement and dispersion of oil slicks in the Arabian Gulf during part of the period of January to March 1991. While other studies on numerical simulations of this event pertain mainly to the Al-Ahmadi spill, the present study simultaneously examines the movement of oil from not only this source but also from Mina Al-bakr and clearly delineates the impact of oil from each of these sources. The numerical model is used for computing the currents due to tides, winds and bathymetric influences. This model has only one open boundary at the strait of Hormuz where the incoming tide is prescribed. The model time step is 100 seconds, sufficient to resolve the hydrodynamical effects. However, the slick movement simulations are carried out with current fields determined at hourly intervals. The surface wind field has been computed from synoptic weather charts using the geostropic relationship, supplemented by some climatological data. The oil slick is advected by the net current as obtained above and the lateral spreading of the oil is simulated through a random walk process with an appropriate eddy diffusion coefficient. The influence of the magnitude of the eddy diffusion coefficient on the spread of the oil is examined in detail. Refloatation of beached oil parcels is also considered in the model simulations. The model simulations are compared with slick location as obtained from remotely sensed observations. The importance of real-time winds in spill movement prediction is demonstrated through a comparison with model simulations obtained with monthly mean climatological winds.     

Levels and Distribution of Petroleum Hydrocarbons in the Coastal Waters and Sediments of the United Arab Emirates in the Arabian Gulf and the Gulf of Oman

The levels and distributions of petroleum hydrocarbons incoastal waters and sediments of the United Arab Emirates (U. A. E.) along theArabian Gulf and the Gulf of Oman were investigated. Oil concentrations in the waters ofthe U. A. E. were below the 15 μg L^-1 and ranged from 1.6 to 13 μg L^-1.Petroleum hydrocarbons showed different pattern of distribution in the Arabian Gulf and the Gulf of Oman withmore or less similar values. Horizontal distribution of petroleum hydrocarbons atthe Arabian Gulf showed significant differences between most sites. At the Gulf ofOman, similar oil concentrations were measured at different sites. Meanwhile,vertical distributions of petroleum hydrocarbons indicated higher concentrations atsurface layers of the Arabian Gulf compared to bottom layers. Whereas, more or less similarconcentrations were measured at the Gulf of Oman. The concentration of petroleum hydrocarbons in marinesediments varied from 2.5 to 8.2 μg g^-1 (dry sediment weight), with higher concentrations at theArabian Gulf compared to the Gulf of Oman. The pattern of distribution for petroleumhydrocarbons in marine sediments resembled to some extent the distribution of organiccarbon in marine sediments. The study revealed that the concentrations ofpetroleum hydrocarbons in waters and sediments of the investigated area are not highcompared to other areas of the world.     

Man-made litter on the shores of the United Arab Emirates on the Arabian Gulf and the Gulf of Oman

Frequency of occurrence, composition, and distribution of litter accumulating on western and eastern beaches of the Arabian Gulf and the Gulf of Oman, UAE, were investigated. In this study 27000 m² of UAE beaches were examined and 22771 items noted. An estimated 13.5×10⁶ man-made items are stranded along 800 km of Arabian Gulf and Gulf of Oman shorelines. Plastic fragments constituted 27.1% of the total items encountered. A strong correlation was found between plastic fragments and plastic bottles. Fishing floats and nettings represented 16.9% of the total items examined. A highly significant correlation (r=0.89) existed between the number of polystyrene blocks used as fishing floats and ropes, and nettings washed ashore. The west coast on the Arabian Gulf exhibited a much higher level of pollution by man-made debris than the east coast on the Gulf of Oman. Potential sources are pointed out and comparisons with other regions of the world are discussed.     

Modeling Water Quality Impacts of Petroleum Contaminated Soils in a Reservoir Catchment

Soil contamination due to spills or leaks of crude oils andrefined hydrocarbons is a common problem. Estimation of spillvolume is a crucial issue in order to determine the expectedcontaminating life span of contaminated soils. The directprocedure to determine the amount of hydrocarbon in soil is to measure the concentration of total petroleum hydrocarbon (TPH) in soil samples. The primary objective of this study was toassess the potential effects of oil contaminated soils on thewater quality of Devegecidi dam reservoir. For this purpose,limited spill data available were evaluated and soil samplingstudies were conducted in the Beykan oil field to analyze forTPH on oil contaminated soils. Available spill and measured soilTPH data were used in a subsequent modeling study to assess thereservoir water quality impacts due to dissolved mass leachingfrom hydrocarbon contaminated soils. Evaluation of availablespill data between 1989 and 1995 revealed that a total of 252recorded spills resulted in a net spill of 395 tons. The majortypes of oil spills were identified as well heads (WH), returnlines/flow lines (RL/FL), and power oil lines (POL). A total of211 soil samples was collected at selected well heads andanalyzed for TPH in the laboratory. TPH results revealed aconcentration range between 600 and 115 500 mg kg^-1 with a meanconcentration of 20 300 mg kg^-1. Modeling studies focused onbehavior assessment and involved two major components. The firstcomponent is a soil-leaching submodel for estimating theleachate concentration and contaminant mass leaching out of thecontaminated soil body. The second component is a reservoirwater quality submodel assuming complete-mix conditions forestimating the changes of hydrocarbon concentration in thereservoir water as a function of time. These two components arecoupled via a mass inflow term present in the reservoir waterquality model, accounting for contaminant mass loadingcontributed by the leaching of contaminated soil. Simulation runs performed under conservative conditions assuming an annualaverage oil spill volume of 95 tons and the minimum reservoirvolume of 7.3 × 10⁶ m³ revealed that there isno imminent threat to reservoir water quality from the dissolved phase contaminants soils. Limited amount of availablemeasurements of TPH concentrations in soil samples and benzeneconcentrations in reservoir water samples supported model results.     

Adsorption Kinetics and Capacity of Fatty Acid-Modified Banana Trunk Fibers for Oil in Water

Oil spill leaves detrimental effects to environment, living organisms, and economy. As such, it is of considerable interest to find an effective, simple, and inexpensive method to treat this calamity. This work reports the use of banana trunk fibers (BTF) modified with oleic acid, stearic acid, castor oil, and palm oil for oil spill recovery. The maximum sorption capacity, effect of oil to water ratio, effect of light oil fractions, and effect of dissolved organic compounds in weathered oil-contaminated seawater were studied. It is found that BTF treated with oleic acid exhibited the best sorption capacity for engine oil, dissolved organic compounds in weathered oil, and light oil fractions. The equilibrium process was described well by the Freundlich isotherm model, and the kinetic studies show good correlation coefficients for a pseudo-second-order kinetic model.     

Residues of organochlorine pesticides in fish from the Arabian Gulf

High-resolution electron capture gas chromatography was used to determine residue levels of organochlorine pesticides in 13 commercially important fish species collected from the NW Arabian Gulf. While most of the residues were below the detection limit of 1 μg kg^?1 wet weight, relatively low concentrations of ΣDDT, endrin and dieldrin were detected in the edbile tissue of these fishes. The ΣDDT residue levels ranged from 2 to l 1μg kg^?1 wet weight, endrin ranged from none detected (nd) to 45 μg kg^?1 and dieldrin from nd to 5 μg kg^?1. A definite correlation was established between total organochlorine pesticide residues and lipid content (r = 0.6) for the NW Arabian Gulf fishes. Comparison with fish from Hor-al-Hammar Lake (an area that used to be sprayed with pesticides) has shown that the latter contained significantly higher residue levels. The ΣDDT residue levels ranged from 5 to 45 μg kg^?1 wet weight, endrin from 3 to 83 μg kg^?1 and dieldrin from nd to 4 μg kg^?1 Based upon the observation that the original DDT (p, p′-DDT) was identified in the NW Arabian Gulf fishes, it has been concluded that there was a recent input of DDT to this region. Since DDT application has been banned in Iraq, consequently it was assumed that DDT must originate from a more remote source.     

Responses of Selected U.S. Gulf Coast Marsh Macrophyte Species to Oiling and Commercial Cleaners

A shoreline cleaner was tested to determine its effectiveness in removing different types of oil from selected US Gulf coastal marsh macrophytes. Bulltongue (Sagittaria lancifolia L.), three cornered grass (Scirpus olneyi E. & G.) and broadleaf cattail (Typha latifolia L.) were subjected to oil application and cleaning in a greenhouse and the subsequent effects on plant functions were evaluated during the period immediately after treatment initiation. Plant stomatal functioning, photosynthesis, respiration, regeneration, growth and biomass were monitored. Two types of oil, South Louisiana Crude (SLC) or Arabian Medium Crude (AMC) were used. The treatments included: control (no oil or cleaner), cleaner only (COREXIT 9580 only, no oil), oiled with SLC or AMC only (no cleaner), and oiled using SLC or AMC and cleaned with COREXIT 9580 after two days. The existing leaves on the macrophytes at the time of treatment application directly subjected to oiling (but not cleaned) did not recover from the effects of oiling in all of the study species. However, leaves under oil+cleaner treatments or leaves developed during the post-oiling period (new leaves) showed a different pattern of response. For instance, in bulltongue plants, new leaves had stomatal conductances at or close to the values recorded for control plants. However, new leaves and leaves subjected to oil+cleaner treatment in cattail and three-cornered plants, had stomatal conductances significantly lower than their respective control plants. However, photosynthetic and respiration data indicated no overall significant differences within each species across treatments. Thus, the physiological functions of the study species had apparently recovered from the initial adverse effects of oiling within the experimental period. Based on photosynthetic and respiration data, the study species sensitivity ranking is similar. Furthermore, there were no significant differences in physiological responses of the study species to oil types. In addition, above-ground biomass was not affected significantly by the treatments in bulltongue or cattail but was reduced significantly in three-corner plants. Based on the overall physiological and biomass data, bulltongue was the least sensitive of the three species to SLC and AMC oil types than the other species while cattail appeared to be the most sensitive. Any beneficial effects of the cleaner may be more pronounced in plant species highly sensitive to specific oil types than the species studied.     

H2O2/NaOH改性玉米秸秆制备石油吸附剂的实验研究

本文采用H2O2/NaOH对玉米秸秆（RCS）进行改性来制备可吸附石油的生物质吸附剂（HNCS）。通过模拟实验,比较了不同改性时间的HNCS吸油量,发现改性14h的吸油量最大,达14.08g·g-1,而改性前RCS仅为4.33g·g-1,改性使得吸油量提高了325%,且吸油速率更快。通过扫描电子显微镜（SEM）、比表面积/孔隙度分析仪和傅里叶红外光谱仪（FT-IR）,对改性前后样品结构进行表征,同时采用洗涤剂法和硫酸法对纤维素、半纤维素、木质素含量进行测定,结果发现：改性后的HNCS表面更加粗糙,且出现大量的吸附孔隙,比表面积为7.14m·2g-1,表面亲水性官能团减少,纤维素含量增加而木质素含量减少。这说明吸油量和吸油速率受到吸附剂表面官能团、比表面积和孔隙/间隙的影响。     

流场分析与智能建模在机油泵CAD中的联合应用

针对发动机机油泵新产品设计过程中性能预测难和试验成本高的问题,提出一种将流场数值模拟和神经网络智能建模预测技术联合应用于机油泵产品设计过程的新方法。结合机油泵初始设计结构尺寸,建立其内部流场的CFD（computathonal fluid dynamics）仿真模型;通过流场数值模拟分析,获取一定量的机油泵转速、供油压力、供油温度和供油流量数据;构建描述机油泵供油特性的BP神经网络模型,利用流场数值模拟结果数据作为样本训练该网络模型;最后利用训练好的BP神经网络智能模型对各种工况下机油泵的供油特性进行预测分析。实例验证结果表明,采用文中方法取得很好的仿真分析效果,可以用于在设计阶段对发动机机油泵产品的结构进行优化并调控产品的工作特性。     

Determination of geographical origin of olive oils using 13C nuclear magnetic resonance spectroscopy. I - Classification of olive oils of the Puglia region with denomination of protected origin

13C nuclear magnetic resonance spectroscopy was used to classify olive oils from the three production areas of the Puglia region labeled with the "denomination of protected origin" (DPO) Terra di Bari, Colline di Brindisi, and Dauno. High resolution (13)C spectra of 173 olive oil samples were measured, and the intensity data of triacylglycerol resonances were processed by using linear discriminant analysis, which was carried out stepwise for variable selection. The olive oil samples from the DPOs Colline di Brindisi and Terra di Bari were 90% correctly classified, whereas only 74% of "Dauno" DPO oils were classified in the true group. The performance of the discriminant model was verified by applying the cross-validation procedure based on the "leave one out" formalism. The discriminant model was evaluated against a blind test set of olive oils from the three DPO areas. All the oils used for the purpose were correctly assigned to their respective groups, with the exception of the Dauno oil samples based on the Coratina cv. They were misclassified as Terra di Bari oils because of a common monovarietal composition.     

Emission of Pesticides into the Air

During and after the application of a pesticide in agriculture, a substantial fraction of the dosage may enter the atmosphere and be transported over varying distances downwind of the target. The rate and extent of the emission during application, predominantly as spray particle drift, depends primarily on the application method (equipment and technique), the formulation and environmental conditions, whereas the emission after application depends primarily on the properties of the pesticide, soils, crops and environmental conditions. The fraction of the dosage that misses the target area may be high in some cases and more experimental data on this loss term are needed for various application types and weather conditions. Such data are necessary to test spray drift models, and for further model development and verification as well. Following application, the emission of soil fumigants and soil incorporated pesticides into the air can be measured and computed with reasonable accuracy, but further model development is needed to improve the reliability of the model predictions. For soil surface applied pesticides reliable measurement methods are available, but there is not yet a reliable model. Further model development is required which must be verified by field experiments. Few data are available on pesticide volatilization from plants and more field experiments are also needed to study the fate processes on the plants. Once this information is available, a model needs to be developed to predict the volatilization of pesticides from plants, which, again, should be verified with field measurements. For regional emission estimates, a link between data on the temporal and spatial pesticide use and a geographical information system for crops and soils with their characteristics is needed.

     

Changes in the morphological properties of rzhavozems under the influence of oil contamination

The work considers the morphological structure of sandy loam gleyic rzhavozems in the background area and at the site of an oil spill on a field in the northeastern part of Sakhalin Island. Correlations between the total content of oil hydrocarbons (OHCs) in the horizon AY and its color parameters measured using the Munsell, RGB, and Lab systems are revealed. Linear regression equations are presented. Signs of technogenic impact in the top horizons of the rzhavozems at various levels of oil contamination are presented.     

Information needs and priorities for assessing the sensitivity of marine birds to oil spills

Our experience in developing models to predict the potential impacts of oil spills on colonially breeding marine birds has revealed some major gaps in the information available on these systems. We consider the availability of data for a variety of parameters of seabird biology that are required in modelling efforts, and assign provisional priorities to our information needs. In order to develop means of predicting the impacts of oil spills on seabirds, we suggest that colony- or site-specific information on the timing of reproduction and colony occupancy, chick growth rates and body weights, several metabolic parameters, flight speed, and food load size is of relatively low overall priority. Intermediate priority is assigned to the collection of specific data on the dynamics of oil spills, the age and breeding structure of the populations, reproductive success, foraging activity budgets and flight paths, flight costs, and the response of growing chicks to food deprivation. We suggest that studies of seabird biology should give highest priority to obtaining information on population sizes, the probability of adult death upon encountering a spill, age-specific fecundity and survivorship, the time required in foraging trips, the lag time in the response of birds to an oil spill, foraging rate as a function of resource density, and changes in the availability of resources to the birds as a consequence of oil spills.     

Evidence for the recovery of the waters off the east coast of Nova Scotia from the effects of a major oil spill

The background levels of residual oils in the Western North Atlantic off the east coast of Nova Scotia decreased from approximately 6 to about 2 μgl^?1 during May 1970 to January 1971 following a major spill of Bunker C fuel oil from the tanker ARROW which was wrecked in Chedabucto Bay, Nova Scotia on February 4, 1970.     

Transformation of soil and plant cover contaminated with oil and salt water in the middle Ob’ river basin

Changes in the soil and plant cover caused by contamination with oil and salt water in the middle Ob’ river region were estimated using geoinformatic and geostatistic approaches. The largest technogenically salinized areas include oligotrophic peat soils due to the extensive spill of highly saline waters on the flat bog surface and eutrophic soils located in lower topographic positions. The natural self-purification of salinized mineral forest soils proceeds within 1–2 years after the spill. The dominant species of secondary plant communities were detected. Correlations were revealed between the residual oil and chloride contents and the total projective plant cover.     

Evaluation of Heavy Metal Pollution in the Arabian Gulf Using the Clam Meretrix meretrix Linnaeus, 1758

The present study is an attempt to assess the heavy metal contamination in the marine environment of the Arabian Gulf of Saudi Arabia. The concentrations of heavy metals in water and the soft tissues of the bivalve species Meretrix meretrix Linnaeus, 1758, from different stations along the Arabian Gulf coastline, were determined during the summer season of 2008. Bioaccumulation of some heavy metals (Cd, Pb, Cu, and Zn) in fresh parts of the clam (M. meretrix) was measured by an atomic absorption spectrophotometer. The average concentrations of heavy metals in the clam tissues were 0.224?C0.908, 0.294?C2.496, 3.528?C8.196, and 12.864?C24.56 mg/kg wet weight for Cd, Pb, Cu, and Zn, respectively. In water, the mean concentration values of these metals were arranged in the following descending order: Pb > Cu > Zn > Cd. The heavy metal concentrations in tissues of M. meretrix were within the acceptable standards set by the US Environmental Protection Agency, the Commission Européenne, and the Food and Drug Administration of the USA. From the human public health point of view, these results seem to show no possibility of acute toxicities of Cd, Cu, Pb, and Zn if the edible clam is consumed. It is recommended that relevant authorities should carry out a continual assessment on the levels of these pollutants in the studied area.     

Toxicity of seawater and sand affected by the Prestige fuel-oil spill using bivalve and sea urchin embryogenesis bioassays

An evaluation of the toxicity of seawater and sand sampled from an area of the Galician coast (NW Iberian Peninsula), highly impacted by the Prestige fuel-oil spill, was attempted by using marine invertebrate embryogenesis bioassays with bivalves and sea urchins. Water samples were frozen and toxicity testing was delayed until the reproductive season of the sea urchins. Sand samples were elutriated and tested within 13 d from sampling, using bivalves from commercial stocks. Sand elutriates were non toxic for embryos despite visual presence of small tar balls. In contrast, seawater from the most impacted site was highly toxic during the first days after the spill, with complete inhibition of embryogenesis even after 4-fold dilution. In a lower degree toxicity persisted for two months in light-exposed coastal water. These findings stress the impact to water column organisms of the less conspicuous and frequently overlooked water-accommodated fraction, rather than the more visible oil slick.     

DBCP residue studies in soil and well water from two south carolina peach orchards

Soil samples collected from a peach orchard near a well containing 1 pg kg^?1 1,2-dibromo-3chloropropane (DBCP) (contaminated) and from a peach orchard with a well containing 0.1 pg kg^?1 DBCP (uncontaminated) contained less than 0.1 gg kg^?1 and 0.5 μg kg^?1 DBCP residue, respectively. Soil profiles did not explain the presence of DBCP in the contaminated well. However, a possible spill of DBCP approximately 30 m from the contaminated well may have contaminated the well water. Soil samples taken at the site of the possible spill contained high concentrations of DBCP in the upper meter and at 6.1 m where the water table was encountered. The data indicate that the water contamination resulted from this spill of DBCP and not from normal agricultural use.     

Long-term survival of de-oiled Cape gannets Morus capensis after the Castillo de Bellver oil spill of 1983

After oil spills, oiled wildlife are regularly cleaned at considerable cost. Yet the conservation value of this intervention has been questioned, mostly because cleaned animals appear to have poor post-release survival. However, reliable long-term data are needed to judge the success of such programs. We used 16 ring recoveries to estimate survival of 932 Cape gannets (Morus capensis) that were oiled, cleaned and released in 1983. For the period 1989-2006, we further compared survival of 162 surviving cleaned gannets to that of 10,558 non-oiled gannets using capture-recapture data. We used modern statistical tools that account for recapture probabilities, recovery rates, transience, and temporary absence from the breeding colonies. Mean annual survival rates of de-oiled gannets ranged from 0.84 (se = 0.05) to 0.88 (se = 0.02), depending on analysis and colony. Between 1989 and 2006, rehabilitated gannets survived slightly less well than unoiled birds, but the difference was similar to the difference in survival between the two colonies where the birds were studied. Our results show subtle long-term effects of oiling and subsequent treatment. However, they also show that cleaned gannets can survive at almost the same rate as unoiled birds, at least if they survived the initial years after release. Rehabilitation of these birds may thus be a valuable conservation intervention for this localised species where a single spill can threaten a large proportion of the world population.