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341.
Since its conception, “oil sands” has been the name of a pro-development narrative seeking to convince skeptics that bitumen saturating the sandstone of Alberta’s Athabasca region ought to be extracted and chemically altered into Synthetic Crude Oil (SCO). Over the decades, the nature of skepticism has changed, and thus oil sands (along with its meanings and claims) has been continually reproduced so as to placate new criticisms. This paper offers a discursive genealogy of the oil sands narrative, demonstrating how it has been transformed from what was throughout the twentieth century a materially situated “narrative of promise” aiming to prove that SCO production was physically possible and that it could be commercially profitable, into what by 2015 was at its core a largely reactive “rhetoric of sustainability” aiming to convince a new class of critics that, contrary to their claims, SCO was in fact being produced in an environmentally responsible manner.  相似文献   
342.
Solvent extraction for heavy crude oil removal from contaminated soils   总被引:1,自引:0,他引:1  
Li X  Du Y  Wu G  Li Z  Li H  Sui H 《Chemosphere》2012,88(2):245-249
A new strategy of heavy crude oil removal from contaminated soils was studied. The hexane-acetone solvent mixture was used to investigate the ability of solvent extraction technique for cleaning up soils under various extraction conditions. The mixtures of hexane and acetone (25 vol%) were demonstrated to be the most effective in removing petroleum hydrocarbons from contaminated soils and approx 90% of saturates, naphthene aromatics, polar aromatics, and 60% of nC7-asphaltenes were removed. Kinetic experiments demonstrated that the equilibrium was reached in 5 min and the majority of the oil pollutants were removed within 0.5 min. The effect of the ratio between solvent and soil on the extraction efficiency was also studied and results showed that the efficiency would increase following the higher solvent soil ratio. Then the multistage continuous extraction was considered to enhance the removal efficiency of oil pollutants. Three stages crosscurrent and countercurrent solvent extraction with the solvent soil ratio 6:1 removed 97% oil contaminants from soil. Clearly the results showed that the mixed-solvent of hexane and acetone (25 vol%) with character of low-toxic, acceptable cost and high efficiency was promising in solvent extraction to remove heavy oil fractions as well as petroleum hydrocarbons from contaminated soils.  相似文献   
343.
● Organic solvent extracted fewer Cd/Pb in rapeseed oil than physical pressing. Brassica rapa transferred fewer Cd and Pb from seed to oil than Brassica napus . ● Carcinogenic risk mainly from Cd and worth more concern than noncarcinogenic risk. ● Organic solvent specially SLB pose less heath risk for oil than physical pressing. ● Rapeseed oil posed higher carcinogenic risk for rural residents than urban. Substitute planting with rapeseed offers promise for safely using large areas of Cd/Pb-contaminated farmland. Cd/Pb distributions during rapeseed oil production were investigated and health risks posed by the oil were assessed. Tests were performed using three cultivars (Brassica rapa SYH and ZS100 and Brassica napus QY-1) and four oil extraction techniques (mechanical and low-temperature pressing and n-hexane and subcritical low-temperature butane extraction). The amounts of Cd and Pb in oil were 0.73%–8.44% and 3.14%–11.76%, respectively, of the amounts in rapeseed and were strongly affected by the cultivar and oil extraction technique. The heavy metal (HM) concentrations were lower in solvent-extracted oil (particularly subcritical low-temperature butane extracted oil, in which HMs were not detected) than mechanically pressed oil. The Cd and Pb transfer indices were lower (meaning larger proportions of HMs were retained by the rapeseed meal) for B. rapa than B. napus. This was attributed to a high HM binding protein content of B. rapa seed. Health risks to humans were assessed using a probabilistic risk assessment model. The carcinogenic risk was mainly (97.1%–99.9%) caused by Cd and poses more concern than non-carcinogenic risk. Stronger health risks are posed by mechanically pressed than solvent-extracted oil, and higher carcinogenic risks are posed to people living in rural areas than urban areas. Substitute planting with B. rapa and extracting oil with organic solvent (preferably subcritical low-temperature butane) are optimal for safely utilizing Cd/Pb-contaminated soil. Attention should be paid to the health risks posed by Cd in oil to rural populations.  相似文献   
344.
The wet landscape approach to oil sands tailings reclamation in the Athabasca Oil Sands region involves creating wetlands from fluid tailings in mined-out pits. We measured time to metamorphosis, thyroid hormone status, and detoxification enzyme (EROD) induction in Wood frog (Lithobates sylvaticus) tadpoles raised on reclaimed oil sands wetlands of different ages [young (≤7 yr) vs. old (>7 yr)] and compared data with tadpoles raised on reference (control) wetlands. Metamorphosis was delayed or never occurred in tadpoles raised in young tailings; those exposed to older tailings developed similarly to those in reference wetlands. Thyroid hormone disruption likely played an important role in the metamorphosis delay as the T3:T4 ratio was lowest in tadpoles raised in young, tailings-affected wetlands. Our findings suggest tailings wetlands become less toxic with age, and that these amphibians will be able to complete their life cycle in tailing wetlands that have sufficiently detoxified with age.  相似文献   
345.
We measured heavy metal concentrations in yellow-legged gulls (n = 196) and European shags (n = 189) in order to assess the temporal pattern of contaminant exposure following the Prestige oil spill in November 2002. We analysed Pb, Cu, Zn, Cr, Ni and V levels in chick feathers sampled at four colonies during seven post-spill years (2003-2009), and compared results with pre-spill levels obtained from feathers of juvenile shag corpses (grown in spring/summer 2002). Following the Prestige wreck, Cu (4.3-10 μg g−1) and Pb concentrations (1.0-1.4 μg g−1) were, respectively, between two and five times higher than pre-spill levels (1.5-3.6 and 0.1-0.4 μg g−1), but returned to previous background concentrations after three years. Our study highlights the suitability of chick feathers of seabirds for assessing the impact of oil spills on heavy metal contamination, and provides the best evidence to date on the persistence of oil pollution after the Prestige incident.  相似文献   
346.
In its role as a competitive producer of phosphate and potash Jordan has not suffered noticeably from the Resource Curse over the past 50 years. However, the effects on its economy because of its geographical proximity to major oil-producing states have been both positive and negative. It is arguable that an oil resource curse has applied to Jordan.  相似文献   
347.
In this study, cobalt supported oil palm shell activated carbon (Co/OPS-AC) and ZSM-5 zeolite (Co/ZSM-5) catalysts have been prepared for dry reforming of methane. Cobalt ratios of 6.0 and 14.0 wt% were deposited via wet impregnation method to the OPS-AC and ZSM-5 catalysts. The catalysts were characterized by XRD, N2 adsorption--desorption isotherms, BET surface area, SEM, FESEM-EDX, TPR-H2, and TPD-NH3. The dry reforming of methane was performed using a micro reactor system under the condition of 10,000 ml/h.g-cat, 3 atm, CH4/CO2 ratio of 1.2:1.0 and temperature range from 923 K to 1023 K. The gaseous products were analyzed by gas chromatography (GC) with thermal conductivity detector (TCD) and further quantified to determine the conversions of CH4 and CO2, and the yields of CO and H2. Experimental results revealed both catalysts exhibited lower conversions of CO2 and CH4 with the increase in temperature from 923 K to 1023 K. The reduced conversions may be due to the formation of carboneous substance on the catalyst known as coking. Comparatively, Co/OPS-AC gave higher conversions of CO2 and CH4 as well as higher yields of H2 and CO as it has a higher surface area than Co/ZSM-5 which subsequently rendered higher activity for the reforming of methane. With the increasing cobalt loadings and reaction temperature, OPS-AC(14) catalyst exhibited improved activity and H2/CO ratio. Based on these results, cobalt supported OPS activated carbon catalyst was suggested to be more effective for CO2 and CH4 conversions.  相似文献   
348.
新型油水分离器在油田污水处理中的应用实验   总被引:4,自引:0,他引:4  
叙述了一种新型油水分离器--奥地利费雷公司的波纹板式重力加速聚集型油水分离器的工作原理,及其在国内几个油田的中试试验情况,试验结果表明,该油水分离器处理效果相当明显,除油率平均达94.59%,具有相当的经济、社会和环境效益。  相似文献   
349.
含油污水中胶质和沥青质含量的紫外测定方法   总被引:1,自引:0,他引:1  
探讨用紫外分光光度计快速测定经Al2O3吸附色谱柱分离后的含油污水中胶质?沥青质含量的方法,并且用国内外分析原油及渣油时所通用的四组分分析方法做对比实验,二者相对误差一般小于±5%?实验表明不同油田含油污水中胶质?沥青质含量不同,在污水处理剂的研制及筛选中,应考虑油的组成的影响   相似文献   
350.
492Q发动机分层进气燃烧净化节油系统的研究,是为了使国产492Q发动机的油耗水平下降,同时也降低其排放对大气的污染。为此,采用稀薄燃烧原理,使发动机在空燃比(AF)为18左右也可正常燃烧,达到降低油耗,同时也减少了CH、CO、NO_x的排放。   相似文献   
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