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221.
渤海大气气溶胶元素组成及物源分析 总被引:11,自引:0,他引:11
利用电感耦合等离子体-光发射光谱法(ICP-OES)分析了2000年夏季渤海大气气溶胶样品,给出了渤海气溶胶污染物浓度分布特点,结合气象资料和富集因子进行了元素物源分析.分析结果表明,辽东湾的污染程度高于其他海区,气溶胶中含量最高的元素是Zn(1638ng/m3),含量最低的是V(2ng/m3).渤海气溶胶中Pb、Zn、Cu和Ni等具有较高的富集因子.辽东湾Pb的富集因子达4000以上,Zn的富集因子普遍大于其他海区.Pb、Mn、Cu、V等含量的相对大小与同期北京的分析结果一致.综合分析表明,渤海大气严重受到陆地人为排放污染物的影响. 相似文献
222.
Donatella Desideri Maria Assunta Meli Francesco Nonnis Marzano Carla Roselli Corrado Testa Cesare Triulzi Marina Vaghi 《Chemistry and Ecology》1996,12(4):259-264
Sediment samples of different strata (0-3 and 12-15 cm) were collected between 1990 and 1992 during seasonal cruises in the Northern Adriatic Sea. A complete mapping of the Sr-90, Cs-137, Pu-238 and Pu-239(240) concentrations was obtained for samples covering a wide area, stretching from the Gulf of Trieste towards the Ancona shoreline. Sr-90 concentrations varied between 1.5 and 6.5 Bq kg-1 dw, Cs-137 was in the range 0.9-38.9 Bq kg-1 dw, Pu-239(240) in the range 0.08-1.5 Bq kg-1 dw and Pu-238 around 0.03 Bq kg-1 dw. Special reference was also put on the comparison between the off-shore environment and data obtained from samples collected inside the Po river delta. in spite of the major accumulation of Cs-137 inside the estuarine environment, higher concentrations of strontium and plutonium isotopes were detected in the offshore environment. 相似文献
223.
As part of a joint USA/USSR Environmental Agreement to determine the distribution and concentration of Chernobyl radioactivity in the northwest Black Sea area, the sediment from eight stations was collected and analyzed to assess the ability of this material to adsorb radiocaesium. Batch tests were conducted in which Cs-137 tracer was added to mixtures of sediment and bottom water, with contact solutions ranging from 85 Bq ml-1 to 1,760 Bq ml-1. This work was done in an argon atmosphere at 9.5°C, which is the average temperature of the sediment. Isotherms were linear for all cores and distribution ratios (RD) calculated from the slopes of the isotherms ranged from 660 to 1,660 ml g-1. These isotherms fit a simplified Freundlich isotherm. Correlations of RD to a number of sediment parameters describing texture and mineralogy were determined. A close relationship was observed between RD for caesium and the percentage of illite contained in the samples. 相似文献
224.
The threat of man-induced global change on the nations of the South Asian seas region varies from place to place because of
differences in exposure to monsoons and stoms, differences in local tectonics and subsidence, and variations in air and sea
climates. Because several nations are involved, some having subsistence budgets, and given the cost of deriving independently
a comprehensive response to global change, the similarities and differences between national settings must be identified soon.
These comparisons will form the basis for local response strategies: the similarities provide a basis for responses similar
to that of other nations and the differences provide for local adaptation. That climate change on the South Asian coastal
region will have an impact is certain: its economics, environment, and coastal land uses are dominated to a certain extent
by this marine influence. The extent of these impacts, however, is uncertain. Accompanying global change will be changes in
sea level, differences in storm climate, and altered precipitation patterns; science cannot define today what pattern these
changes will take. Because global change is inevitable—although its magnitude, timing, and geographic distribution are unknown—the
South Asian seas region should begin the appropriate research and planning studies to set forth a reasoned response to global
change, for implementation when scientific evidence for global change is more quantitative. 相似文献
225.
R. W. P. M. Laane J. Van Der Meer A. De Vries A. Van Der Giessen 《Environmental management》1990,14(2):221-227
During the winter period an inverse linear relation is found between the concentration of dissolved nutrients (phosphorus
and nitrogen) and salinity in the Dutch coastal zone. This indicates a conservative behavior of these compounds from the river,
through the estuary to the sea. During summer this relation is much more scattered because of biological processes. The physical
and statistical properties of the relationship between salinity and the concentration of dissolved inorganic phosphorus and
nitrogen are used to calculate when, where, and how many samples have to be taken in order to monitor a reduction of a compound
accurately. It appeared that at any given salinity in the estuary and in the sea, the winter period is the most suitable season
to detect a reduction of a given dissolved compound. The higher the salinity in the estuary, the more samples are required
to prove the reduction significantly. A reduction of only 10% cannot even be demonstrated by field measurements during summer
at salinities above 25. It is concluded that one cruise from the river to the sea, covering the salinities from 0 to 35 during
the winter period, aimed at establishing the relationship between the concentration and salinity by taking samples at a salinity
interval of for instance 1%, is sufficient to monitor a wide-ranging reduction of 10%–50% in both the fresh water and marine
water. This program must be combined with a sampling at a salinity of 0, directed to determine the riverine temporal variability. 相似文献
226.
During oil and gas production, water is often extracted from geological formations along with the hydrocarbons. These "produced
waters" have been discharged to Nueces Bay since the turn of the century. These effluents were found to be highly toxic, and
sediments in the vicinity of the discharges were also toxic. We developed a map of wells and produced-water discharge sites
in the vicinity of Nueces Bay and identified numerous unplugged wells suitable for conversion to produced water disposal wells.
An economic analysis of conversion to subterranean injection of produced water indicates that most of the wells currently
in production could pay out the cost of conversion to injection in one to three years. The use of one injection well for two
or more water-producing wells could yield greater savings. Wells that could not support the cost of injection are small producers,
and their loss would not constitute a major loss of jobs or dollars to the area. This study could serve as a useful model
for evaluating the economic feasibility of conversion to injection in other areas of Texas and Louisiana. 相似文献
227.
本文对渤海滨州沿岸各入海河口进行了现状污染指标的主组元分析,获得表征各河口的主要污染指标,进而说明各河口污染类型。结果表明,潮河等四河口基本属有机污染型。 相似文献
228.
N. G. O. Boroffka H. Obernhänsli G. A. Achatov N. V. Aladin K. M. Baipakov A. Erzhanova A. HöRnig S. Krivonogov D. A. Lobas T. V. Savel’eva B. Wünnemann 《Mitigation and Adaptation Strategies for Global Change》2005,10(1):71-85
The shore of Lake Aral in Kazakhstan is a perfect area for studying the human adaptation strategy to past climate changes. New archaeological material, gathered along the northern shores during the expedition of the INTAS project CLIMAN, is briefly presented. Changes in settlement activity during the Atlantic and Subboreal are related to lake level changes of the Aral Sea. A previ-ously proposed lake level maximum needs to be revised. In particular the lake level stand at 72/73 m, with an assumed age of 5000 BP is definitely refused. Based on the presented data the maximum lake level most probably never reached beyond 57/58 mean average sea level (masl). Furthermore the regression during the 15th–16th centuries has been underestimated. It may have been lower than the present day level. Thus the present desiccation of the Aral Sea is historically not unique, as a similar regression, probably induced by man as well, has occurred at least once during history. A readjustment of the water level is, therefore, possible at any time. 相似文献
229.
230.
北疆250年地表水资源变化特征及未来趋势预测 总被引:7,自引:0,他引:7
本文从北疆年轮场重建了北疆250年的地表水资源,探讨气候-地表水资源-年轮之间的关系,分析地表水资源的长期变化特征,预测其变化趋势,为北疆地表水资源的研究与利用提供了新的参考依据。 相似文献