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1.
Concentrations of trace elements and heavy metals (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, Se, Sr, V and Zn) in the Danjiangkou Reservoir, the water source area of the Middle Route of China’s interbasin South to North Water Transfer Project, were analyzed using an Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) and compared with the national and international standards for drinking water. The results indicated that concentrations of As, Pb, Sb and Se in the Reservoir exceeded the standards and they would pose health risk for residents in the region and the water receiving areas of the interbasin water transfer project. Spatial and temporal variability of the trace elements and heavy metals in the Reservoir implies their mixed sources of natural processing and anthropogenic activities in the upper drainage of the Reservoir. The research results would help develop water resource management and conservation strategy for the interbasin water transfer project.  相似文献   

2.
《Applied Geochemistry》2005,20(10):1848-1856
Geochemical data on dissolved major, minor and trace constituents in groundwater samples from Xi-Sha coral islands (Paratas Islands) reveal the main processes responsible for their geochemical evolution. Multivariate statistical analysis indicates four sources of solutes: (1) seawater intrusion due to limited groundwater recharge; (2) leaching of heavy metals from imported granite soil; (3) leaching of toxic elements such as As due to guano-soil erosion and historical phosphatic guano mining; and (4) local and regional contamination characterized by high loadings of Cu, Ag and Hg. Although process 1 dominates the geochemical characteristics of the groundwater, process 4 indicates the significant role of anthropogenic impact by local (e.g., Cu) and regional (e.g., Hg) sources. Such contamination in groundwater will potentially impose adverse effects on the fragile ecosystem of the coral islands. It is necessary to monitor microorganisms associated with human feces in the nearshore water column as well as nutrient levels in coastal waters in order to further assess the impact of human activities on the ecosystem of these islands.  相似文献   

3.
During the late Mesozoic, an unusually broad range of alkalic magma compositions was erupted along the southern border of the São Francisco craton of Brazil. This magmatic activity includes carbonatite, kimberlite, lamprophyre, lamproite, syenite and the largest known example of extrusive kamafugite, the Mata da Corda formation. To determine the nature of the sources of this magmatism, and their geochemical history, an Os isotope study along with major and trace element and Sr, Nd and Pb isotope analyses of kimberlitic, lamproitic and kamafugitic rocks from the Alto Paranaíba province of Brazil was undertaken. This complements recent geochemical and isotopic studies of these magmas. The Os isotope data for Alto Paranaíba samples point to a peridotitic lithospheric mantle source for the kimberlites and lamproites that was variably depleted in Re, presumably by melt removal at some time between the late Archean and mid-Proterozoic. These lithospheric peridotites experienced LIL-element enrichment by fluid/melt metasomatism at roughly 1 Ga, most likely during mobile belt formation along the western border of the São Francisco craton. Kamafugitic samples have very radiogenic Os, suggestive of mafic (e.g. pyroxenite, websterite, eclogite) source materials that again appear to have been stabilized in the lithospheric mantle of Brazil in the mid to late Proterozoic. The Os isotope evidence for lithospheric sources for the Alto Paranaíba activity, coupled with Sr, Nd and Pb isotopic characteristics that overlap those of the Walvis Ridge hot-spot trace indicate that the EM1 component in South Atlantic ocean island basalts most likely represents the influence of delaminated Brazilian lithospheric mantle mixed into mantle circulation beneath the South Atlantic and is not related to the plume(s) commonly associated with this ocean island magmatism.  相似文献   

4.
The paper discusses the ionic sources and chemical quality of the waters (surface and groundwater) around the Tehri reservoir in Uttarakhand, Garhwal, Himalaya, for drinking and irrigation purposes. The main Bhagirathi river, tributary streams and springs and groundwater are the main sources of water for the reservoir and inhabitant living around it. Fifty-two water samples were collected from springs, handpumps (borewell) and streams and were analysed for major ions. The pH is varying from 6.8 to 8.6 and EC from 28 to 820 μS/cm. The chemical composition of water is dominated by Ca, Mg and HCO3. The high ratio of Ca + Mg/Na + K and low ratio of Na + K/TZ indicate dominance of carbonate dissolution as the main solute acquisition process in this part of Lesser Himalaya. The trilinear and X–Y plots suggest less contribution from silicate weathering and anthropogenic activities. The excess of Na over Cl indicating much of the alkalis in the waters of Tehri area have source other than precipitation possibly from silicate weathering. Recharged by meteoric water, the quality of water in the study area is controlled essentially by chemical processes occurring between water and lithology and locally altered by human activities. Among the trace metals the concentration of Fe at few locations has marginally exceeded the WHO and BIS standards of drinking water. The analytical result computed from various water quality indices indicate fairly good quality of water for both drinking and irrigation purposes. The factor analysis performed on the major ion data indicate two factors are the most important affecting the water quality of the area.  相似文献   

5.
Trace contaminants enter major estuaries such as San Francisco Bay from a variety of point and nonpoint sources and may then be repartitioned between solid and aqueous phases or altered in chemical speciation. Chemical speciation affects the bioavailability of metals as well as organic ligands to planktonic and benthic organisms, and the partitioning of these solutes between phases. Our previous, work in south San Francisco Bay indicated that sulfide complexation with metals may be of particular importance because of the thermodynamic stability of these complexes. Although the water column of the bay is consistently well-oxygenated and typically unstratified with respect to dissolved oxygen, the kinetics of sulfide oxidation could exert at least transient controls on metal speciation. Our initial data on dissolved sulfides in the main channel of both the northern and southern components of the bay consistently indicate submicromolar concenrations (from <1 nM to 162 nM), as one would expect in an oxidizing environment. However, chemical speciation calculations over the range of observed sulfide concentrations indicate that these trace concentrations in the bay water column can markedly affect chemical speciation of ecologically significant trace metals such as cadmium, copper, and zinc.  相似文献   

6.
Factor analysis was applied to the hydrochemical data set of Manukan Island in order to extract the principal factors corresponding to the different sources of variation in the hydrochemistry. The application of varimax rotation was to ensure the clear definition of the main sources of variation in the hydrochemistry. The geochemical data of dissolved major, minor and trace constituents in the groundwater samples indicates the main processes responsible for the geochemistry evolution. By using Kaiser normalization, principal factors were extracted from the data for each location. The analysis reveals that there are four sources of solutes: (1) seawater intrusion; (2) leaching process of underlying rock mediated by pH; (3) minerals weathering process and (4) dissolution of carbonate minerals characterized by high loadings of Ca, Zn and Mg. Such processes are dominated by the significant role of anthropogenic impact from the over abstraction of fresh water from the aquifer. Those factors contributed to the changes of the groundwater geochemistry behavior explain the effect of rising extraction of freshwater from the aquifer.  相似文献   

7.
Dissolved trace elements and heavy metals of waters and sediments in the ten shallow lakes in the middle and lower reaches of the Yangtze River region were determined to identify their composition and spatial distribution, and to assess the extent of their environmentally detrimental effects by comparison with water and sediment quality guidelines. Results indicated that As and Pb were the main pollutants in lake waters and Mn and Hg the potential ones, while As, Cu and Pb were the main pollutants in lake sediments. Their spatial distribution indicated that Daye Lake was seriously polluted by metals, which was corroborated by cluster analysis. Higher concentrations of trace elements have been found in lakes downstream of the Yangtze River delta, and higher concentrations of metals have been recorded in sediments of upstream lakes, suggesting that metals in water were more sensitive to anthropogenic activities and that metals in sediment were mainly controlled by minerals. Correlation analyses demonstrated that there were stronger associations among metals in lake sediments than those in lake waters, and their good relationships suggested the common sources. Further research on the subject will help develop water quality management with the aim of restoring shallow lakes in the Yangtze River.  相似文献   

8.
Aji-Chay River is one of the most important surface reservoirs of northwest of Iran, because it passes through Tabriz city and discharges to Urmia Lake, one of the largest permanent salty lakes in the world. The main objectives of the present study are to evaluate its overall water quality and to explore its hydrogeochemical characteristics, including the potential contamination from heavy metals and metalloids such as Co, Pb, Zn, Cd, Cu, Cr, Al and As. For this purpose, 12 water samples were collected from the main river body and its tributaries within Tabriz plain. The Piper diagram classified water samples mainly into Na–Cl and secondary into Ca–HCO3 and mixed Ca–Mg–Cl types, denoting a profound salinization effect. The cross-plots showed that natural geochemical processes including dissolution of minerals (e.g., carbonates, evaporites and silicates), as well as ion exchange, are the predominant factors that contribute to fluvial hydrogeochemistry, while anthropogenic activities (industrial and agricultural) impose supplementary effects. Cluster analysis classified samples into two distinct clusters; samples of cluster B appear to have elevated electrical conductivity (EC) values and trace metals concentrations such as Co, Pb and Cd, while SiO2 and Zn are low in comparison with the samples of the cluster A. The main processes controlling Aji-Chay River hydrogeochemistry and water quality were identified to be salinization and rock weathering. Both are related with geogenic sources which enrich river system with elevated values of Na+, Cl?, Ca2+, Mg2+, K+, SO4 2? and EC as a direct effect of evaporites leaching and elevated values of Pb and Cd as an impact from the weathering process of volcanic formations. According to the US salinity diagram, all of the water samples are unsuitable for irrigation as having moderate to bad quality.  相似文献   

9.
Chromium and lead concentrations and distribution have been fully studied within Bahía Blanca estuary inner area, which is strongly influenced by urban and industrial stress. Not only metals dissolved in estuarine water but also those included in sediments and suspended particulate matters (SPM) were measured. In all cases, internationally standardized protocols were applied to metal measurements, including analytical quality check test through analysis of certified reference materials. Total metal contents from surface sediments and SPM were compared with those from a historical database of the area, as well as with values representing the natural geochemical baseline within the system. Results showed that heavy metal pollution is mainly localized in the areas close to both industrial effluents discharge system and urban sewage outfall discharge. Data from sequential extractions indicate that metals from anthropogenic sources (i.e., Pb) are potentially more mobile than those inherited from geological parent material (i.e., Cr). The influences of other potential sources of metals (i.e., streams, runoff) were also considered. SPM was clearly identified as the main carrier of the studied heavy metals within the system, and its significance to metals input into sediments and/or biota was verified. Finally, the normalization of measured metal concentrations against background reference elements (i.e., Al or Fe) has allowed to identify that most of the measured Cr was lithogenic, while a significant percentage of Pb was from anthropogenic origin within Bahía Blanca estuary.  相似文献   

10.
太仓郊区河流沉积物重金属污染现状及评价   总被引：4，自引：0，他引：4       下载免费PDF全文
选择太仓市郊区河流沉积物为研究对象,开展了重金属污染现状及评价研究。研究表明,相对于地壳或页岩平均值,沉积物中大部分重金属呈现不同程度的富集;地质累积指数和富集因子分析表明,位于城镇附近的采样点受到污染,且主要污染因子为Cr、Cu、Cd、Pb、Zn等。结果显示,沉积物Zn含量高达1770mg／kg,是农用污泥Zn使用容许最高值500mg／kg的3倍多,沉积物由于Zn、Cr、Cu等的严重污染不能用作施用污泥;利用重金属与Fe之间的相关特征结果显示,城镇工业、生活污水的排放是沉积物重金属污染的主要因素。  相似文献   

11.
River waters play a significant role in supplying naturally- and anthropogenically-derived materials to Lake Qinghai, northeastern Tibetan Plateau. To define the sources and controlling processes for river water chemistry within the Lake Qinghai catchment, high precision ICP-MS trace element concentrations were measured in water samples collected from the Buha River weekly in 2007, and from other major rivers in the post-monsoon (late October 2006) and monsoon (late July 2007) seasons. The distributions of trace elements vary in time and space with distinct seasonal patterns. The primary flux in the Buha River is higher TDS and dissolved Al, B, Cr, Li, Mo, Rb, Sr and U during springtime than those during other seasons and is attributed to the inputs derived from both rock weathering and atmospheric processes. Among these elements, the fluxes of dissolved Cr, B and Rb are strongly influenced by eolian dust input. The fluxes of dissolved Li, Mo, Sr and U are also influenced by weathering processes, reflecting the sensitivity of chemical weathering to monsoon conditions. The anthropogenic sources appear to be the dominant contribution to potentially harmful metals (Ni, Cu, Co, Zn and Pb), with high fluxes at onset of the main discharge pulses due, at least partially, to a runoff washout effect. For other major rivers, except for Ba, concentrations of trace elements are higher in the monsoon than in the post-monsoon season. A total of 38.5 ± 3.1 tons of potentially harmful elements are transported into the lake annually, despite human activities within the catchment being limited. Nearly all river water samples contain dissolved trace elements below the World Health Organization guidelines for drinking water, with the exception of As and B in the Daotang River water samples collected in late July probably mobilized from underlying lacustrine sediments.  相似文献   

12.
沉积物微量金属元素在重建水体环境变化中的意义   总被引：7，自引：0，他引：7  
沉积物所记录的微量金属含量与形态的变化是指示人类活动影响下水体环境变化的有效指标,主要用于指示沉积物重金属污染、水体初级生产力变化和氧化还原条件等方面的水体环境状况。总体而言,沉积物中微量金属含量在近一个世纪以来显著上升,反映了采矿、冶金、污水排放、化肥使用、煤炭和石油燃烧等各种人类活动造成水体和沉积物重金属污染的记录作为浮游植物微量营养元素,Cu、Zn、Ni、Ba、Cd等在沉积物中的记录可以指示水体初级生产力水平。U、Mo、V、Cu、Cd、Mn等氧化还原敏感元素在沉积物中的富集或贫化,及其比值(如Re/Mo、Cd/U、Th/U和V/Sc)的变化,是指示水体和沉积物氧化还原环境的有效指标。但需要指出的是,在受人类活动影响的水体中,这些生产力和氧化还原指标很少能指示水体生产力或氧化还原状况,可能主要与人类活动同时造成这些金属元素大量污染输入而掩盖了其自生来源和内在变化的沉积记录有关。所以,对沉积物中微量金属元素来源的判别(陆源碎屑输入、人为输入和水体自生来源)是重建水体环境变化的重要前提。本文总结了多种化学和统计学方法(包括同位素示踪法、化学提取法、富集因子法和主成分分析法等)在沉积物金属来源判别中的应用另外,成岩作用等多种因素会干扰沉积物金属记录对环境变化的指示作用,所以构建多元素指标来综合判断沉积物记录所反映的环境信息是今后的研究所必须关注的  相似文献   

13.
The analyses of 248 samples have revealed that the composition and distribution patterns of sediments within the Albemarle estuarine system (AES) represent a complex interaction between multiple sediment sources, basin morphology and evolution, and associated estuarine processes. Three sediment end-member types are dominant: sand, peat, and organic-rich mud (ORM). Throughout the AES, shallow perimeter platforms and associated sediment-bank shorelines are eroded into Pleistocene units. Shoreline recession supplies sand to the platforms and mud to the central basins; these sediments mix with suspended sediment from the fluvial drainages. Swamp forest-peat and marsh-peat shorelines are actively eroding and supply fine organic detritus to produce the dominant ORM sediment in the central basins. Perimeter platform sands grade into ORM on the platform slope. ORM constitutes about 70% of the benthic habitats within the AES and has an average composition of 76.2% inorganic mud, 13.1% sand, and 10.7% organic matter. The characteristics of ORM greatly affect the benthic community structure, chemical quality of the sediments, and the water quality of the estuary. ORM readily moves in and out of the water column in response to natural and anthropogenic activities, affecting water column turbidity and trace and major element geochemistry. Organic matter and clay minerals in ORM are chemically reactive and interact with the water column to adsorb or release contaminants, nutrients, and gases. Thus, ORM acts as both a sink and source for many different chemical constituents in the water column and plays important, but poorly understood, functions in the physical and chemical dynamics of estuarine ecosystems.  相似文献   

14.
Groundwater samples from three different states of southeastern Nigeria were analyzed for a range of physicochemical parameters and heavy metal constituents in order to determine their potability as drinking water sources. The results indicate that the physicochemical parameters (pH, temperature, TDS, TH, electrical conductivity, Cl?, NO3 ? and SO4 2?) tested for have most of their values fall within the permissible limits given by the Nigerian and World Health Organization standards for drinking water quality. The results also reveal that apart from Cu and Pb the rest of the tested heavy metals (As, Zn, Ni, total Fe, Cd and Mn) recorded values that are significantly above the maximum permissible limits for drinking water purposes and therefore have the potential to cause health impacts for long-term potable use. On the basis of principal component analysis, the sources of the measured chemical constituents are likely to be predominantly geogenic (weathering of soluble minerals in the formations) and partly anthropogenic (industrial effluent, agricultural practices and mining activities). Single-factor ANOVA tests indicated insignificant differences in the datasets within/between states or geological units. Caution or adequate treatment is generally required when utilizing the groundwater from the area for drinking purpose due to the elevated metal concentrations and rating as poor to unsuitable water quality.  相似文献   

15.
The sources impacting the water chemistry of the Nakdong River (NR) in South Korea were investigated in order to examine the pollution mechanism including the fate and transport of the contaminants and how much such sources may affect its main channel of water resource. Water samples were collected between 2007 and 2008 from 8 sites along a 510 km downstream transect of the NR, and chemical and isotopic compositions of the water samples were evaluated to identify natural and anthropogenic sources contributing to the water chemistry of the NR. The results showed that the major ion concentrations were mainly controlled by chemical weathering that occurred in the watershed, in which a silicate weathering is more dominant than a carbonate weathering. The 87Sr/86Sr ratios of the water samples were in a range from 0.71043 to 0.71520 within those of the Mesozoic volcanogenic sedimentary rocks long developed in the watershed, thereby supporting the fact that the water chemistry is governed by a chemical weathering. The δ34S values varied in a narrow range of 1.8–3.1‰, regardless of spatial and seasonal variations. Mass balance calculations indicated that the contributions of chemical weathering and anthropogenic sources during summer time increased along a downstream transect, from 67.3 ± 1.3 to 73.6 ± 0.5% and from 6.0 to 15.7%, respectively. In contrast, the contribution of chemical weathering during winter time decreased from 82.7 ± 0.8 to 72.5 ± 0.3%, while anthropogenic contribution increased up to 22.2%. These results indicated that the water chemistry of the NR was mainly caused by a chemical weathering, followed by anthropogenic inputs and rainwater. This study will provide baseline information for comparing the water quality issue before and after the implementation of the Four Rivers Restoration Project of South Korea.  相似文献   

16.
A dynamic scheme for water movements over a flood in a small watershed was proposed in a previous paper [Ben Othman, D., Luck, J.M., Tournoud, M.G., 1997. Geochemistry and water dynamics: application to short-time scale flood phenomena in a small Mediterranean catchment: I. Alkalis, alkali-earths and Sr isotopes. Chem. Geol. [140] 9–28] based on major, alkali–alkali earth trace elements and Sr isotopes. In the present paper, metal contents and Pb isotope data are reported for the same samples, and compared to natural and anthropogenic local sources analysed for this purpose. Water treatment plants have stable but show relatively large variations, presumably related to yet unidentified (industrial?) Pb sources. Some Cu–Zn-rich chemicals used extensively on vineyards have unradiogenic around 17.7. Local rains sampled over two years show roughly similar low values. Pb from rocks is variable and more radiogenic ( ≈18.8–22.8). Except for the first hours, trace element concentrations in the dissolved load are similar to or slightly higher than those observed over the year, and similar to other moderately anthropogenic areas [Shiller, A.M., Boyle, E.A., 1987. Variability of dissolved trace metals in the Mississippi river. Geochim. Cosmochim. Acta [51] 3273–3277] for [Pb] (0.05–0.45 nM), [Zn] (10–75 nM) and [Cd] (0.03–0.18 nM). Dissolved [U] and [Co] show simple variations correlated to carbonate, related to local natural sources. Most trace elements in the particulate load are strongly correlated. Lead isotopes in the dissolved and particulate loads show ranges over the flood, again similar to those observed over the year ( ≈17.9–18.3), implying the same sources. The very good alignments observed in and vs. diagrams, especially for the particulate, are interpreted as mixing phenomena. Generally Pb isotopic signature of the dissolved load is less radiogenic than the particulate, indicating differences in sources or proportions and absence of isotopic equilibration with respect to the time of transfer. Pb isotopes shift regularly with time away from the road runoff endmember towards more radiogenic values. The strong negative correlation between Pb isotopes in the particulate load and Sr isotopes in the dissolved load, observed for the first time in a small watershed, probably reflects the local coupling between mechanical and chemical erosion, respectively.  相似文献   

17.
Heavy metals and physicochemical characteristics of the different sites of the municipal solid waste dumpsite at Olusosun Landfill, Lagos, Nigeria, were investigated. The dormant site of the landfill has the potential of being a source of immediate environmental risk compared to the active and abandoned site, with the active site exhibiting tendency to be a likely source of Pb, Cd and Zn pollution. Zn was the most abundant metal in the area (0.264–0.947 mg/L) while Cd concentration was the lowest (0.001–0.022 mg/L). Pb, Cd, Zn were from anthropogenic sources and correlated significantly with chemical oxygen demand and oil and grease. Cu and Cr were more abundant in the dormant site and are attached to the solids as indicated by their significant correlation with TS and SS. The physicochemical characteristic of the leachate from the landfill indicate that they were more alkaline in nature, with TA range of 2354 to 7946 mg/L while the chemical oxygen demand values was also high 518.14 to 725.01 mg/L. The comparative analysis of the dormant site with other dormant site reveal a moderate concentration of the parameters measured but could contaminate the neighboring groundwater if not checked.  相似文献   

18.
The concentration of metals (Pb, As, Co, Cu, Ni, Zn, Fe and Mn) was investigated in water and sediment samples of E?irdir Lake. The Lake is the second largest fresh water lake of Turkey and it is used as drinking water in the region. The anthropogenic pollutants are primary sources of trace metals which are negatively affected lake water quality. These negative effects were observed in both lake water and bottom sediments. According to obtained data, Pb, Cu, Ni, Fe and Zn have significant enrichment in sediments samples. In addition, the hydrodynamic model of the lake was determined as effectively for Pb, Co, Cu, Ni, Zn, Fe and Mn accumulations. Also, the effect of anthropogenic pollutants was found to be more dominant than geogenic effect in metal accumulation of the lake bottom sediments. Therefore, anthropogenic pollutants within the lake basin should be consistently controlled for the sustainable usage of the lake.  相似文献   

19.
Eighteen sediment samples and six water-column samples were collected in a small (6 km2), coastal embayment (Port Jefferson Harbor, New York) to define a high-resolution spatial distribution of metals and to elucidate sources of contaminants to the harbor. Sediment metal (Ag, Cu, Fe, Ni, Pb, V, and Zn) concentrations varied widely, reflecting differences in sediment grain size, with higher metal concentrations located in the fine-grained inner harbor sediments. Calculated enrichment factors for these sediments show that Ag, Pb, Cu, and Zn are elevated relative to both crustal abundances and their respective abundances in sediments in central Long Island Sound. Metal concentrations were 1.2 to 10 fold greater in water from the inner harbor compared to water from Long Island Sound collected outside the mouth of the harbor. Spatial variations in trace metals in surface waters within the bay parallel the spatial variations of trace metals in sediments within the harbor. Elevated water-column metal concentrations appear to be partially derived from a combination of diagenetic remobilization from contaminated sediments (e.g., Ag) and anthropogenic sources (e.g., Cu and Zn) within the southern portions of the harbor. Although the National Status and Trends Program had reported previously that sediment metal concentrations in Port Jefferson Harbor were low, the results of this study show sediment metals have high spatial variability and are enriched in the inner harbor sediments at levels comparable to more urbanized western north shore Long Island harbors.  相似文献   

20.
《Applied Geochemistry》2004,19(7):1065-1074
Potentially toxic metals exist in many reservoirs of surface water and therefore require an understanding of their occurrence, distribution, and mobility. The sediment accumulating at the bottom of the Dillon Reservoir, Colorado is contaminated with metals (Cu, Pb, Zn, Cd, Mo, etc.) that are primarily sorbed to Fe and Al hydroxides present in the sediment. The metals are derived from weathering of mineralized bedrock and mine tailings in the surrounding drainage basins. Sediment samples from the Dillon Reservoir were analyzed for major and trace elements and acidification experiments were performed to quantify the fraction of metals released from the sediment as a function of changes in pH. The highest percentages of metals are released from the sediment at low pH with the exception of Mo which has the highest percent released at near neutral pH. In addition, seasonal fluctuations in the concentrations of metals in the water of the Dillon Reservoir can be explained by changes in pH of as low as 0.2 pH units.  相似文献   

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