A tracer study in an Alaskan gravel beach and its implications on the persistence of the Exxon Valdez oil   总被引：2，自引：0，他引：2  

Li H  Boufadel MC 《Marine pollution bulletin》2011,62(6):1261-1269

Despite great efforts including bioremediation, the 1989 Exxon Valdez oil spills persist in many gravel beaches in Prince William Sound, Alaska, USA. To explore this mystery, a lithium tracer study was conducted along two transects on one of these beaches. The tracer injections and transports were successfully simulated using the 2-dimensional numerical model MARUN. The tracer stayed much longer in the oil-persisting, right transect (facing landwand) than in the clean, left transect. If the tracer is approximately regarded as oils, oils in the upper layer would have more opportunities to enter the lower layer in the right transect than in the left one. This may qualitatively explain the oil persistence within the right transect. When the tracer is regarded as nutrients, the long stay of nutrients within the right transect implies that the oil persistence along the right transect was not due to the lack of nutrients during the bioremediation.  相似文献   

Polycyclic aromatic hydrocarbons (PAHs) in a large South American industrial coastal area (Santos Estuary, Southeastern Brazil): sources and depositional history     

Martins CC  Bícego MC  Mahiques MM  Figueira RC  Tessler MG  Montone RC 《Marine pollution bulletin》2011,63(5-12):452-458

Located in southeastern Brazil, the Santos Estuary has the most important industrial and urban population area of South America. Since the 1950's, increased urbanization and industrialization near the estuary margins has caused the degradation of mangroves and has increased the discharge of sewage and industrial effluents. The main objectives of this work were to determine the concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) in sediment cores in order to investigate the input of these substances in the last 50 years. The PAHs analyses indicated multiple sources of these compounds (oil and pyrolitic origin), basically anthropogenic contributions from biomass, coal and fossil fuels combustion. The distribution of PAHs in the cores was associated with the formation and development of Cubat?o industrial complex and the Santos harbour, waste disposal, world oil crisis and the pollution control program, which results in the decrease of organic pollutants input in this area.  相似文献   

Quantifying bank storage of variably saturated aquifers   总被引：1，自引：0，他引：1  

Li H  Boufadel MC  Weaver JW 《Ground water》2008,46(6):841-850

Numerical simulations were conducted to quantify bank storage in a variably saturated, homogenous, and anisotropic aquifer abutting a stream during rising stream stage. Seepage faces and bank slopes ranging from 1/3 to 100/3 were simulated. The initial conditions were assumed steady-state flow with water draining toward the stream. Then, the stream level rose at a constant rate to the specified elevation of the water table given by the landward boundary condition and stayed there until the system reached a new steady state. This represents a highly simplified version of a real world hydrograph. For the specific examples considered, the following conclusions can be made. The volume of surface water entering the bank increased with the rate of stream level rise, became negligible when the rate of rise was slow, and approached a positive constant when the rate was large. Also, the volume decreased with the dimensionless parameter M (the product of the anisotropy ratio and the square of the domain's aspect ratio). When M was large (>10), bank storage was small because most pore space was initially saturated with ground water due to the presence of a significant seepage face. When M was small, the seepage face became insignificant and capillarity began to play a role. The weaker the capillary effect, the easier for surface water to enter the bank. The effect of the capillary forces on the volume of surface water entering the bank was significant and could not be neglected.  相似文献   

Assessment of chemical dispersant effectiveness in a wave tank under regular non-breaking and breaking wave conditions     

Li Z  Lee K  King T  Boufadel MC  Venosa AD 《Marine pollution bulletin》2008,56(5):903-912

Current chemical dispersant effectiveness tests for product selection are commonly performed with bench-scale testing apparatus. However, for the assessment of oil dispersant effectiveness under real sea state conditions, test protocols are required to have hydrodynamic conditions closer to the natural environment, including transport and dilution effects. To achieve this goal, Fisheries and Oceans Canada and the US Environmental Protection Agency (EPA) designed and constructed a wave tank system to study chemical dispersant effectiveness under controlled mixing energy conditions (regular non-breaking, spilling breaking, and plunging breaking waves). Quantification of oil dispersant effectiveness was based on observed changes in dispersed oil concentrations and oil-droplet size distribution. The study results quantitatively demonstrated that total dispersed oil concentration and breakup kinetics of oil droplets in the water column were strongly dependent on the presence of chemical dispersants and the influence of breaking waves. These data on the effectiveness of dispersants as a function of sea state will have significant implications in the drafting of future operational guidelines for dispersant use at sea.  相似文献   

Spatial distribution of sedimentary linear alkylbenzenes and faecal steroids of Santos Bay and adjoining continental shelf, SW Atlantic, Brazil: origin and fate of sewage contamination in the shallow coastal environment   总被引：1，自引：0，他引：1  

Martins CC  Ferreira JA  Taniguchi S  Mahiques MM  Bícego MC  Montone RC 《Marine pollution bulletin》2008,56(7):1359-1363

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新疆昆仑山地区某大型水利枢纽工程场地地震危险性概率分析     

彭亮  吴彬  沈军  唐丽华  陈建波 《内陆地震》2008,22(3):234-242

利用地震危险性概率分析方法对大（Ⅰ）型一等工程－某大型水利枢纽工程所在的场址进行地震危险性分析;该拟建工程场址所在的西昆仑地震带是新疆境内地震活动强度最高、频度最大的地震带,拟建工程坝高库大,为了进行准确的地震危险性分析研究。本研究根据区域地震活动性及地震构造研究成果,确定了地震活动性参数,按照构造类比、历史地震重演原则划分了潜在震源区;在分析了区域地震活动环境和地震构造等因素后,综合评价其对场地地震危险性的影响;根据确定的地震动衰减关系及地震带、潜在震源区的地震活动性参数,应用概率方法计算得出了场地不同概率水平的水平向基岩峰值加速度。其结果做为适合该水库的工程场地地震危险性分析结论,用于指导工程选址、设计、抗震设防。  相似文献   

信阳上天梯膨润土矿工艺矿物学特征研究   总被引：11，自引：0，他引：11  

黄彦林  李英堂  吴彬 《岩石矿物学杂志》2000,19(1):88-96

为了使信阳上天梯膨润土矿得到高效合理的开发应用,从应用性基础研究出发,首先开展了上天膨润土矿工艺矿物学特征研究。分析了矿石的矿物组成、结构构造及理化工艺性能,研究了蒙脱石的成分组成、晶体化学特点、层间电荷及其对开发应用的影响。在此基础上,对该矿石进行了高纯钠基膨润土的制备、柱撑蒙脱石试验和高效活性白土的制取。  相似文献   

Au—As—Sb矿化剪切带中成矿流体—岩石相互作用与物质迁移...     

Boir.  MC 吴彬 《华东地质学院学报》1990,13(3):16-20

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用激光等离子体发射光谱分析单个流体包裹体中的单原子离子     

Boir.  MC 刘晓东 《地质地球化学》1993,(2):56-61

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巴西东北部巴伊亚州法曾达——巴西莱亚金矿剪切带中金淀积的构造及岩 …     

Rein.  MC 钱壮志 《国外地质与勘测》1992,(3):9-14

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