首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 46 毫秒
1.
The results of bioassay and physicochemical analysis of bottom sediments from large water bodies in Northwestern Russia are presented. The water bodies under consideration include Lake Onega, Vygozerskoe Reservoir, and freshwater part of the Neva Estuary (the Eastern Gulf of Finland), which are locally subject to eutrophication and toxic pollution. The potential toxicity of bottom sediments, evaluated by the survival rate of two crustacean species (Gmelinoides fasciatus and Ceriodaphnia affinis) in 7-day tests, varied from high to low values, characterizing 5 quality classes: high, good, moderate, poor, and heavy, with appropriate degrees of toxic pollution from no to very high pollution. Bad zones were identified in the Kondopoga and Petrozavodsk bays of Onega Lake, the northern and southern parts of the Vygozerskoe Reservoir, and the southern part of the Neva Bay near the dam. Bottom sediments were found to have high quality in the open central areas of Lake Onega and the Vygozerskoe Reservoir and in the western part of Neva Estuary.  相似文献   

2.
Water Resources - The issues of formation and assessment of diffuse pollution of water objects in the zones near large mining and chemical industrial complexes are discussed. The study object is...  相似文献   

3.
The results of long-term seasonal oceanographic observations conducted by YugNIRO from 1955 to 1991 in standard cross-sections on the northwestern shelf of the Black Sea and data obtained by monitoring oil and chemical pollution of the marine environment from 1987 to 1993 in the area of gas deposit development are systematized and statistically treated. The oceanographic conditions of pollution field formation in this region are studied. The dynamics and distribution of total concentrations of oil products and microelements (Hg, Cu, Pb, Cd, and Cr) in water and bottom sediments are examined in the areas in Karkinitskii Bay where permanent offshore platforms are operated. The obtained results are compared with data on the background environmental pollution of the Black Sea and World Ocean. A hypothesis is offered to elucidate the possible causes and mechanisms through which offshore gas production affects the hydrochemical conditions on the shelf. The monitoring data are said to be a necessary information basis for the prediction of pollution dynamics in Karkinitskii Bay with the use of a box-type hydroecological model of petroleum hydrocarbon biotransformations in water, and approaches for the use of these data for this purpose are outlined.  相似文献   

4.
Sevastopol Bay is used as an example for the development of criteria for rating anthropogenic impact by elimination fluxes from the water area of post-Chernobyl (90Sr, 137Cs, 239,240Pu) and natural (210Pо) radionuclides, as well as mercury and organochlorine compounds. The differentiation of the bay water area into zones with different biogeochemical conditions and the balance approach to interpreting field observation data were used to assess the conditioning capacity of Sevastopol Bay ecosystem for conservative radioactive and chemical substances by elimination fluxes of pollutants into aqueous depot, which is the open part of the Black Sea and into the geological depot, i.e., its bottom sediment stratum.  相似文献   

5.
The situation in the Kondopozhskaya Bay of Onega Lake, polluted by wastewater of a pulp-and-paper mill is considered. The dynamics of wastewater input over 80 years is analyzed; the rate of such input varied widely in this period because of changes in cellulose production processes. A close correlation was found to exist between the characteristics of the state of aquatic organism communities and the environmental physicochemical characteristics. The pollution indices of water mass and the bed are evaluated, including biological and physicochemical data. Those indices can be used to identify polluted zones of water and bottom sediments in Onega Lake subject to the discharge of wastewaters from pulp-and-paper mill.  相似文献   

6.
庞琰瑾  袁增伟 《湖泊科学》2021,33(2):439-448
如何精细量化降雨径流污染负荷是流域尺度实现面源精准治污全过程控制的重要前提.本研究以水污染较为严重的望虞河西岸综合示范区为例,通过开展不同土地利用类型的降雨观测实验,修正SCS-CN模型中的初损率,并基于土地利用类型遥感解译和降雨径流污染物浓度测定,精细刻画降雨径流中总磷(TP)、总氮(TN)、氨氮(NH3-N)、化学...  相似文献   

7.
Variations in the key indices of the chemical composition of surface waters are studied in a region where these waters are polluted by mining plant wastes. The forms of metals migration and their distribution in the bottom deposits of watercourses are examined. The possible steps for reducing the pollution of water in a watercourse are discussed.  相似文献   

8.
Data on the microelement composition of bottom sediment and water samples from Lake Dautkul for recent years are presented. Concentrations of more than 30 chemical elements are determined using instrumental neutron-activation analysis. This allowed the authors to reveal the regularities in the distribution and accumulation of chemical elements in water and bottom sediments. It is shown that bottom sediments exhibit a cumulative effect and prolonged activity, which adversely affect the aquatic medium and can serve an indicator of anthropogenic impact on the area under consideration.  相似文献   

9.
Strzeszynskie Lake was formerly a slightly eutrophic (meso-eutrophic) water body. The aim of the current research was to define variables on both spatial and seasonal internal phosphorus loading from bottom sediments at five stations located in zones varying in depth, oxygenation, macrophyte presence, and uses of the neighboring catchment area. Ex situ experiments done with the use of intact bottom sediment cores have shown that the highest phosphorus release occurred in the deepest part of the lake and reached 3.6?mg?P/m2d under anoxic conditions during summer thermal stratification. In turn, the internal loading from littoral sediments, which were well aerated all year round, was clearly lower. Furthermore, phosphorus accumulation in the bottom sediment was observed to reach a maximum of 1.45?mg?P/m2 d in autumn. A comparison of the internal loading intensity in lake zones with different land uses of the neighboring catchment area has shown slightly higher values at stations adjacent to the forest catchment area than those used for recreation. Changes in the land use of the catchment area of Strzeszynskie Lake, especially the increase in impermeable surfaces, have led to an increased inflow of external loads after heavy rains, resulting in deterioration in water quality and a delayed increase in internal loading.  相似文献   

10.
A detention-time model of water quality buffer zones is used to evaluate the nonpoint source pollution control effectiveness of riparian forests in a two-county area of the lower Tar River basin, North Carolina. Soil map units, which represent specific combinations of soil, topography, and vegetation characteristics, are compared in terms of their relative ability to filter nitrate in agricultural runoff. All typical riparian forests provide significant water quality protection, but there is a wide variation in buffer effectiveness. This suggests a need for flexibility in determining buffer widths. A range of 15–80 m is appropriate for the soil-landform-vegetation complexes found in riparian zones within the study area. Buffer widths of 60 m — and often much less — are generally adequate on the soils likely to be used for agricultural production.  相似文献   

11.
The results of studying physicochemical properties of bottom sediments in the Kuibyshev Reservoir are given. The evaluated characteristics include their porosity, specific surface area and density, and chemical state characteristics (pH, oil products, organic matter, phenols, and the mobile and total forms of heavy metals). Technogenic geochemical anomalies of bottom sediments are evaluated. The obtained results characterize the environmental state of bottom sediments in the study area.  相似文献   

12.
The distribution of oil hydrocarbons in bottom sediments of Onega Lake was examined. Their qualitative and quantitative composition was examined by methods of IR-spectroscopy and chromatography-mass spectrometry. The background concentrations of oil hydrocarbons in bottom sediments are evaluated and the polluted area is determined. The major regularities in oil hydrocarbon transformations under natural conditions and anthropogenic impact are identified. The quantitative development of the bacterial groups that take part in the transformation of complex organic substances and oil product derivatives in the case of emergency pollution of Petrozavodsk Bay water area by oil products is demonstrated.  相似文献   

13.
To identify the groundwater flow system in the North China Plain, the chemical and stable isotopes of the groundwater and surface water were analysed along the Chaobai River and Yongding River basin. According to the field survey, the study area in the North China Plain was classified hydrogeologically into three parts: mountain, piedmont alluvial fan and lowland areas. The change of electrical conductance and pH values coincided with groundwater flow from mountain to lowland areas. The following groundwater types are recognized: Ca? HCO3 and Ca? Mg? HCO3 in mountain areas, Ca? Mg? HCO3 and Na? K? HCO3 in piedmont alluvial fan areas, and HCO3? Na in lowland areas. The stable isotope distribution of groundwater in the study area also has a good corresponding relation with other chemical characteristics. Stable isotope signatures reveal a major recharge from precipitation and surface water in the mountain areas. Chemical and stable isotope analysis data suggest that mountain and piedmont alluvial fan areas were the major recharge zones and the lowland areas belong to the main discharge zone. Precipitation and surface water were the major sources for groundwater in the North China Plain. Stable isotopic enrichment of groundwater near the dam area in front of the piedmont alluvial fan areas shows that the dam water infiltrated to the ground after evaporation. As a result, from the stable isotope analysis, isotope value of groundwater tends to deplete from sea level (horizontal ground surface) to both top of the mountain and the bottom of the lowland areas in symmetrically. This suggests that groundwater in the study area is controlled by the altitude effect. Shallow groundwater in the study area belongs to the local flow system and deep groundwater part of the regional flow system. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

14.
The results of studies aimed to assess the information significance of the coefficients of bottom accumulation of hydrophobic organic substances and heavy metals as indicators of pollution of freshwater bodies are presented. It is shown that the same value of the coefficient of bottom accumulation may correspond to different situations in water bodies. Methods for the interpretation of data on the state of water bodies based on the coefficient of bottom accumulation and its components are proposed to reliably determine the level and character of pollution. Chronic pollution of a number of freshwater bodies of the Russian Federation is assessed by data on the accumulation of pesticides, oil products, polycyclic aromatic hydrocarbons, and heavy metals in bottom deposits.  相似文献   

15.
In this paper, we analyze two short cores collected in the Tinto estuary (SW Spain), and describe the palaeoenvironmental evolution of this area during the last two millennia, along with the influence of historical mining activities and recent industrial pollution on sediments and microfauna (foraminifera and ostracoda). Although there were no significant changes in the distribution of microorganisms, a first pollution period (0-150 AD) was recorded in high sediment pollution by Cu in the shallow palaeochannels of the middle estuary. During this period and the following 1700 years, tolerant pioneer species of both foraminifera and ostracoda were found predominantly in the inner, protected areas of the estuary, while the bottom sediments were subjected to high hydrodynamic gradients, and consequently showed lower density and diversity of organisms. In the last 150 years, acid mine drainage processes, introduction of a new mining period, and the polluted inputs derived from two industrial processes resulted in increased heavy metal contamination of the bottom sediments, and corresponding extirpation of ostracodes and restriction of foraminifers to the inner zones of the estuary.  相似文献   

16.
The results of studying the concentrations and component composition of hydrocarbons and associated oxidized hydrophobic compounds in water bodies with different degrees of oil product pollution are given. It is shown that the role of biogenic hydrocarbons in the assessment of oil pollution of freshwater bodies, especially those having high biological productivity, can be quite significant. Such assessment requires the examination of their genesis by using the proposed gas-chromatographic and luminescent criteria. The most informative object for observations in the identification of oil and biogenic hydrocarbons for the assessment of chronic oil pollution of freshwater bodies is bottom sediment.  相似文献   

17.
定量解析污染源对水质影响的贡献是水环境精细化管理的重要基础。目前多通过水质和土地利用类型的关系以解析水体污染源的研究,忽略了空间尺度的差异性,引发景观配置不合理的后果。为此,本研究依据考虑空间尺度效应的污染源解析方法,基于异龙湖流域3条主要入湖河流的入湖口监测断面对雨季和旱季的水质数据进行研究。同时利用绝对主成分—多元线性回归模型(APCS-MLR)和bioenv分析揭示河道不同尺度缓冲区的土地利用变化对水质的影响并解析河流主要污染源。研究结果表明:(1)异龙湖主要入湖河流水质表现出季节性差异,旱季期间3条主要入湖河流的浊度、化学需氧量(CODCr)、氨氮(NH3-N)、总磷(TP)和总氮(TN)浓度平均值相比于雨季减幅分别为39.53%、39.93%、94.48%、38.29%和1.72%。其中,入湖河流水体中的TN在旱季和雨季的超标率分别为58%和74%,成为首要污染物;(2)在旱季,20 m缓冲区尺度内河流水质受耕地和裸地占比影响较大,随着空间尺度的扩大,至50～300 m缓冲区尺度时建设用地、林地及水体占比对水质的影响增加;在雨季,C...  相似文献   

18.
The role of bioassay in the pollution control system for water bodies is considered. Studies of the mechanisms of toxic impact of various chemical compounds on aquatic organisms were used to develop a bioindication method to give an integral estimate of water toxicity and determine some classes of chemical pollutants. The results of application of such methods to assessing water quality in Lake Ladoga are given.  相似文献   

19.
Biogeochemical Indicators of Aquatic Ecosystem Pollution by Heavy Metals   总被引：1，自引：0，他引：1  
Leonova  G. A. 《Water Resources》2004,31(2):195-202
The present-day environmental state of some artificial (Irkutsk, Bratsk, and Novosibirsk reservoirs) and natural (lakes in Altai Territory and Yamal-Nenets Autonomous Okrug and the Tom River) water bodies in Western and Eastern Siberia was evaluated using biogeochemical indicators. The biogeochemical approach is presented as the best for establishing zones of risk and environmental disaster, since biogeochemical cycles play important role in aquatic ecosystems and unite all their blocks as a result of biogenic migration of chemical elements. Aquatic ecosystems transformed under anthropogenic impact are recognized and local sources of water pollution are identified.  相似文献   

20.
Lake Umbozero (the second largest in the area and the deepest in Murmansk province) was studied with the aim to establish the biogeochemical features of the distribution of chalcophile elements (Hg, Cd, Pb, As) in water, bottom sediments, and whitefish organs and tissues. Lake Umbozero is subject to the effect of emissions and effluents of mining-and-metallurgical plants in Murmansk province, as well as airborne anthropogenic pollution of global character. Surface and near-bed peaks were recorded in the distribution of Pb and Cd in water mass. Those peaks can be due to phytoplankton development in surface layers and the precipitation of dead organisms and mechanical suspension into bed layers. The mean Pb and Cd concentrations in Umbozero water mass exceed the mean for lake water in taiga zone. Water body pollution manifests itself in an increase in concentrations of elements, such as heavy metals, in the surface layers of bottom sediments. The largest contamination factors were recorded for Cd and Pb. Lake pollution by highly toxic chalcophile elements also caused their accumulation in whitefish organs and tissues: the biological accumulation coefficient is >1 for Cd in kidneys (5.8) and for Hg in kidneys, liver, and muscles (3.6, 3.3, and 2.2, respectively).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号