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51.
ABSTRACT: Aquatic communities in the Boise River were examined from October 1987 to March 1988 to determine whether they were adversely affected by trace elements in effluents from two Boise wastewater treatment facilities. Trace-element concentrations in the Boise River were less than or near analytical-detection levels and were less than chronic toxicity criteria when detectable. Insect communities colonizing artificial substrates upstream and downstream from the wastewater treatment facilities were strongly associated, and coefficients of community loss indicated that effluents had benign enriching effects. The distributions of trace-element-intolerant mayflies indicated that trace-element concentrations in effluents did not adversely affect intolerant organisms in the Boise River. Condition factor of whitefish was significantly increased downstream from the Lander Street wastewater treatment facility and was significantly decreased downstream from the West Boise wastewater treatment facility.  相似文献   
52.
Bivalves are often used as sentinel organisms in monitoring programmes for trace organic contaminants. the animal's physiological state may be important in interpreting trends in contaminant body burden. Simultaneous evaluation of physiological state and organic contaminant concentration in bivalves typically involves removal of a lipid-rich cross-section of the body mass for histopathological and/or gonadal analysis.

In this study, the bias introduced by this technique in the final trace organic concentrations, e.g. of polynuclear aromatic hydrocarbons, chlorinated pesticides and polychlorinated biphenyls, are evaluated on five different size groups of oysters. As a test case, we evaluated the use of this method in the NOAA's Status & Trends Mussel Watch (NS&T) Programme. the average biases introduced by this technique in the final trace organic concentrations in Gulf of Mexico oysters have been increasing since 1986 as a consequence of a continuous decrease in the size of the individuals sampled.  相似文献   
53.
在降雨条件下,利用自动采样器对广西碧水岩地下河出口进行高频采样,分析了碧水岩地下河出口水体中Cu、Pb、Zn、Cd等微量金属元素的水化学动态变化特征,探讨了地下河水中微量金属来源及其对降雨的响应机制.结果表明,地下河水化学组分表现出了较明显的规律,其中主要元素Ca~(2+)、Mg~(2+)、HCO-3等在降雨过程中稀释作用明显,而Al、Mn、TFe、Cu、Pb、Zn、Cd等金属元素对降雨响应敏感,其质量浓度在降雨过程中有所升高,相应质量浓度曲线均表现出多峰值特点,且在最大降雨发生后第9 h达到最大峰值.推断水岩作用、河底沉积物再释放和水土流失是导致河水金属元素浓度增高的原因,金属元素不同来源及地下河双入口的结构特征是形成金属元素质量浓度曲线多峰值的原因,其中水岩作用引起的水化学变化较河底沉积物再释放和水土流失更敏感,而后者是导致河水重金属元素增加的主要原因.监测期间,溶质在地下河中的平均迁移速度约为0.47 km·h~(-1),污染物运移速度较快,因此,通过对岩溶地下河水化学动态的监测,掌握微量金属组分来源及迁移特性,对于地下河水环境污染治理具有重要意义.  相似文献   
54.
洋河流域不同土地利用类型土壤硒(Se)分布及影响因素   总被引:12,自引:1,他引:11  
基于洋河流域土地利用方式、海拔高度、土壤、植被类型等采集流域上下游171个代表性表层土壤(0~10 cm),系统地分析了土壤总硒(Se)含量、分布及影响因素.结果表明,洋河流域土壤总Se含量(以干重(dw)计,下同)在0.02~3.24mg·kg-1之间,几何平均值为0.30 mg·kg-1,高于北京平原(0.20 mg·kg-1)、河北平原(0.19 mg·kg-1)和全国平均值(0.29mg·kg-1).洋河流域少Se(0.13~0.18 mg·kg-1)土壤主要分布在怀安县、宣化县以及怀来县,多数地区土壤处于足Se水平(0.18~0.45 mg·kg-1),除此之外,在万全县、兴和县、天镇县及阳高县分布有富Se(0.45~2.0 mg·kg-1)土壤.不同土地利用类型中Se含量有所差异,Se平均含量由高到低分别为:林地城镇工矿用地草地农业用地,其中农业用地平均含量为0.28 mg·kg-1.成土母质、土壤类型对洋河流域Se含量影响较小.黏粒含量与洋河流域表层土壤中Se相关性最好.Se含量随海拔增高显著增加,随p H增加显著减小.TOC、Fe和Al含量也是影响土壤Se含量的重要因素.  相似文献   
55.
Dissolved ions and suspended participates from twelve water samples from Sohag (different localities) and Aswan (behind and below the High Dam) areas were collected along the River Nile, upper Egypt, which is at present affected seriously by pressure of population, intense industrial and agricultural activities, and atmospheric fallout. Eighteen trace and nine major ions in solution and fourteen metals in suspension were analyzed to establish whether elements are of anthropogenic or natural origin. Results of this study show that the Nile water was contaminated with high concentrations of dissolved lead, and with copper, nickel and mercury to a lesser extent, suggesting that these contaminants are generated from anthropogenic activities. the other dissolved ions in the Nile are of natural origin because their metal concentrations fall within the range of the normal background and average world dissolved values for inland waters. Results show that the usual constituents of suspended particulates in the Nile seem to be some metals (Cu and Zn) adsorbed on iron and manganese oxide/hydroxide. the results also reveal that most trace and major metal particulates increase from south to north due to activities associated with the dense population living along the Nile banks. No significant differences were observed between the chemical composition of trace and major elements taken on the east and west river Nile banks.  相似文献   
56.
The dominant use of coal in power sectors has been associated with adverse environmental impacts. Ambient air monitoring for the two size fractions of particulate matter, respirable suspended particulate matter (RSPM) and non-respirable suspended particulate matter (NRSPM) in the downwind and upwind directions of a large coal-fired power station in central India, was carried out. Collected samples of ambient particulate matter were analysed atomic absorption spectrophotometrically for 15 elements. Spatial variability in elemental composition of RSPM and NRSPM and the degree of enrichment of these toxic metals in RSPM were investigated. A significant spatial variability for the elements in RSPM and NRSPM and higher degrees of enrichment of the elements were observed.  相似文献   
57.
Leaves of the oak, Quercus cerris, and thalli of the epiphytic lichen, Parmelia caperata, from the Travale-Radicondoli geothermal area (central Italy) were analyzed for their trace elements (As, B, Cd, Cu, Fe, Hg, Mn, Pb, Zn). the results showed that concentrations of arsenic and boron in leaf and lichen samples were higher than in remote areas. the mean concentrations of many trace elements were higher in lichens than in oak leaves, suggesting that these organisms can be used in similar biomonitoring studies. the levels of boron and manganese were higher in tree leaves, so that for these two elements, the higher plant foliage could constitute a better biomonitor than lichens. the correlations found between the concentrations of cadmium and manganese in leaves and lichens suggests foliar leaching and washing of the elements down the tree trunk, where lichens may intercept them.  相似文献   
58.
The National Oceanic and Atmospheric Administration's (NOAA) National Status and Trends (NS&T) Programme has analyzed samples of surface sediment collected at almost 300 coastal and estuarine sites throughout the United States since 1984. the overall distributions for concentrations of each element are approximately lognormal allowing a definition of geometric means and of “high” concentrations as those exceeding the mean plus one standard deviation of the lognormal distribution. Those mean and “high” concentrations should be useful for comparing the NS&T data set and with other reports on sediment contamination. A world-wide data set, constructed from data in the literature, was summarized in an identical manner. It was found, after excluding locally extreme values, that the NS&T and world-wide data sets yielded very similar mean and “high” concentrations for Cu, Ni, Pb and Zn. Chromium was the sole element showing higher summary statistics in the NS&T data set, a result attributed to NS&T sampling in areas of naturally (not contaminated) elevated Cr content. It remains undetermined, however, why the world-wide data set, even with exclusion of “hot spots”, yielded higher means and “highs” for Cd, Hg, As, and Ag.  相似文献   
59.
论述了土介质炸点痕迹特征参量及其控制影响因素,通过对国内外现有研究成果的再分析和有效利用,得到爆源特征与炸点痕迹特征参量之间的关系。在此基础上,建立利用土介质上的炸点痕迹反演爆源特征的方法,并实现编程计算。通过实例分析说明了该方法的可行性。  相似文献   
60.
微量元素的相关比值在许多领域都有不同的作用,随着研究工作的日益精细,数据越来越多,使得不少学者要把大量时间花在数据的整理和计算上,既不利于准确的统计,又浪费了时间.在探讨、实现了地壳中微量元素的相关比值的VB程序,使得在运用这些比值时方便、准确、省时,为研究工作减少许多不必要的麻烦.  相似文献   
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