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841.
Subsoil TPH and other petroleum fractions-contamination levels in an oil storage and distribution station in north-central Mexico 总被引:1,自引:0,他引:1
Many oil industry related sites have become contaminated due to the activities characteristic of this industry, such as oil exploration and production, refining, and petro-chemistry. In Mexico, reported hydrocarbon spills for the year 2000 amounted to 185 203, equivalent to 6252 tons (PEMEX, 2000). The first step for the remediation of these polluted sites is to assess the size and intensity of the oil contamination affecting the subsoil and groundwater, followed by a health risk assessment to establish clean up levels. The aim of this work was to characterize the soil and water in a north-central Mexico Oil Storage and Distribution Station (ODSS), in terms of TPHs, gasoline and diesel fractions, BTEX, PAHs, MTBE, and some metals. Besides, measurements of the explosivity index along the ODSS were made and we describe and discuss the risk health assessment analysis performed at the ODSS, as well as the recommendations arising from it. Considering soils with TPH concentrations higher than 2000 mg kg−1, the contaminated areas corresponding to the railway zone is about 12 776.5 m2, to the south of the storage tanks is about 6558 m2, and to the south of the filling tanks is about 783 m2. Total area to be treated is about 20 107 m2 (volume of 20 107 m3), considering 1 m depth. 相似文献
842.
土地利用类型的分维值和稳定性指数空间变异分析 总被引:13,自引:0,他引:13
土地利用类型是一种在自然和人类活动双重作用下的产物,具有不规则、相对不稳定性和复杂性特征,可以利用分形方法进行探讨;分形理论在土地结构研究中的应用涉及土地利用类型分数维的计算、土地利用结构分形研究方法、土地利用结构及其动态变化的分形描述、区域景观结构的分形模型等方面;但土地利用类型的分形机制的空间差异研究少见报道。综合考虑广东省的自然地理环境和社会经济发展状况,文章选择韶关、潮州、汕头、广州作为不同类型区域的代表,基于分形理论计算了耕地、园地、林地、草地、居民点及工矿用地、道路用地、水体和未利用土地8种地类分维值(D)和稳定性指数(Si)以及平均分维值和稳定性指数,从影响土地利用结构的地貌和人文因素两个方面出发,对比和分析了地域之间的D值、Si值的关系,并从中得到了D值和Si值的变化规律。结果表明:(1)复杂的地貌类型是影响土地利用类型D值和Si值的最主要因素;(2)社会经济发展水平一定程度上影响土地利用类型的分维值和稳定性指数;(3)区域土地利用类型的平均分维值、稳定性指数的大小是土地利用结构的综合反映。 相似文献
843.
The response of infaunal macrobenthic communities beneath salmonid seacages to solid organic wastes (food pellets and fish excreta) was tested by means of the ABC-method (abundance, biomass comparison method: Warwick 1986) on samples collected from the SAFCOL seafarm at Badger Cove, southeast Tasmania, from February to July 1988. The intermittent nature of the addition of organic waste allowed us to monitor decline and recovery of the macrofauna, i.e., harvesting of a cage permitted a period of recovery whilst restocking precipitated a decline. The ABC-method proved to be a sensitive indicator of community health. Under a normal feeding regime the macrofaunal community structure indicated a moderately disturbed condition. Only 7 wk after the cage was harvested, species richness had increased markedly and the community adopted an undisturbed condition. Further improvement was apparent 14 wk post-harvest. Similarly, a decline to a moderately disturbed condition was apparent 7 wk after restocking and species richness had declined. No such changes occurred under a cage which contained fish continuously over the same period. 相似文献
844.
水环境中痕量重金属生物活性形态的分析 总被引:6,自引:0,他引:6
水环境中痕量重金属的生物活性形态,包括生物可吸收态和生物毒性形态,这种形态的分析是重金属形态分析研究的一个重要发展方向。对于水环境中重金属对生物的毒害现状评价、潜在危害预测以及水环境容量的确定、排放标准和污染治理方案的制定,具有重要意义。本文总结了各种物理化学法重金属形态分析的结果与生物测试重金属形态测定结果之间的相关性,进而探讨了应用物理化学方法进行金属生物活性形态分析的可行性和特点。 相似文献
845.
846.
IntroductionTheprintinganddyeingindustryhasahighpotentialenvironmentalimpact,principallyduetothereleaseoflargevolumesofwastewaterthatcontainhighorganicchargeandstrongcoloration .Therearemanyprocessestotreatwastewaterfromprintinganddyeingindustry ,butth… 相似文献
847.
城市生活垃圾场垂直防渗技术应用与认识 总被引:2,自引:0,他引:2
为防止生活垃圾场渗滤液扩散 ,造成二次污染 ,本文着重论述了采用帷幕注浆进行垂直防渗的可行性 ,并结合工程实践 ,对生活垃圾场场址选择、帷幕注浆材料使用以及防渗工程布置作了分析和探讨。 相似文献
848.
荧光光谱法鉴别海面溢油源的研究进展 总被引:6,自引:0,他引:6
本文以大量的研究成果介绍了荧光光谱技术在鉴别海面溢油源中的应用和进展。根据普通荧光光谱、同步扫描光谱、可变角同步扫描光谱和总荧光光谱等不同荧光光谱信息特等,论述了荧光光谱的三维特性及维特性及其在溢油鉴别中的应用。同时,结合低温荧光法、磷光光谱法、导数荧光光谱法等辅助方法和技术,介绍了国内外荧光光谱法鉴别海面溢油的新进展和新成果。 相似文献
849.
废塑料的回收利用及降解塑料的生产现状 总被引:5,自引:0,他引:5
介绍了废塑料的再生利用,热分解回收低分子化合物和焚烧回收热能的技术,并对国内降解塑料的生产现状进行了评述。 相似文献
850.
Blood flow across the atrioventricular valves and outflow tracts was measured in 55 normal fetuses and 32 fetuses with haemoglobin (Hb) Bart's disease between 18 and 26 weeks of gestation. The mean velocities remained unchanged in both normal and affected fetuses over the gestations studied. The volume flow across both atrioventricular valves and outflow tracts increased as the gestation advanced in both normal and affected fetuses, but was significantly higher in affected than in normal fetuses. The same magnitude of increased flow was found in both hydropic and non-hydropic fetuses with Hb Bart's disease. These findings suggest that fetuses with severe and long-standing anaemia have a remarkable cardiac compensatory mechanism for the maintenance of tissue oxygenation. In response to anaemia and circulatory loading, the cardiac chambers and outflow tracts enlarge proportionately up to twice the normal values. Because of this response and the operation of the Frank-Starling mechanism, the heart is able to maintain a normal mean velocity of propulsion and the net output is increased to two to three times that in normal fetuses. Hydropic changes in these anaemic fetuses appear unrelated to cardiac failure as cardiac failure is not observed at the time that hydropic changes develop. 相似文献