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1.
Impact of reservoir impoundment-caused groundwater level changes on regional slope stability: a case study in the Loess Plateau of Western China 总被引:3,自引:1,他引:2
This paper reports the results of the in situ application of diffusive gradients in thin-films (DGT) passive samplers for
trace metals (Cd, Co, Cr, Cu, Ni, Pb and Zn) monitoring in transboundary Udy and Lopan rivers of the Seversky Donets watershed
in the Kharkiv region (Ukraine), which has a long history of industrial development. The research discusses potential sources
of DGT-measured labile metals in water and seasonal variations. Our results demonstrate the application of DGT for identifying
and measuring labile metal concentrations in contrasted climate conditions (cold snowy winter and hot summer) and appropriateness
of such a tool for continuous water monitoring with the presence of an ice cover. Results show that DGT-measured concentrations
of most of trace metals were much higher downstream of the wastewater treatment plants discharges than upstream; thus wastewater
treatment plants seemed not able to reduce or to remove trace metals’ contaminations and become major sources of pollutants
in the studied rivers. The calculation of the average metal fluxes based on the DGT-measured concentrations confirmed that
the urban wastewater discharges significantly contribute to the metal fluxes into the Udy and the Lopan rivers during both
low-flow and high-flow periods. Compared to the wastewaters inputs to the rivers, the transboundary effect is limited, but
should be taken into account as the origin of some metals is from sources located on the adjacent Russian territory. 相似文献
2.
Pb、Zn、Cd和Cr等元素的生物有效性研究——以胶州湾水生系统为例 总被引:4,自引:1,他引:3
本文首先利用同站位多介质同采的资料分析研究了各环境介质中的不同痕量金属对生物富集的贡献,提出孔隙水中Pb、Zn、Cd、Cr对生物体中同名组分富集的贡献较大;进而采用PHREEQC软件模拟了孔隙水中Pb、Zn、Cd、Cr四种元素的组分存在形态,结果表明:PbCO3、Zn2 、CdCl2、Cr(OH)3分别为孔隙水中Pb、Zn、Cd、Cr的优势态,但其生物有效形态依次为PbSO4、ZnOHCl、CdCl 、Cr(OH)2 。最后作者提出生物对其所处环境介质中痕量金属的富集并不取决于痕量金属的总量或其相应的优势态浓度的多寡,而是取决于痕量金属的生物有效态的浓度大小。 相似文献
3.
《Applied Geochemistry》2002,17(4):475-492
Trace metal concentrations in soils and in stream and estuarine sediments from a subtropical urban watershed in Hawaii are presented. The results are placed in the context of historical studies of environmental quality (water, soils, and sediment) in Hawaii to elucidate sources of trace elements and the processes responsible for their distribution. This work builds on earlier studies on sediments of Ala Wai Canal of urban Honolulu by examining spatial and temporal variations in the trace elements throughout the watershed. Natural processes and anthropogenic activity in urban Honolulu contribute to spatial and temporal variations of trace element concentrations throughout the watershed. Enrichment of trace elements in watershed soils result, in some cases, from contributions attributed to the weathering of volcanic rocks, as well as to a more variable anthropogenic input that reflects changes in land use in Honolulu. Varying concentrations of As, Cd, Cu, Pb and Zn in sediments reflect about 60 a of anthropogenic activity in Honolulu. Land use has a strong impact on the spatial distribution and abundance of selected trace elements in soils and stream sediments. As noted in continental US settings, the phasing out of Pb-alkyl fuel additives has decreased Pb inputs to recently deposited estuarine sediments. Yet, a substantial historical anthropogenic Pb inventory remains in soils of the watershed and erosion of surface soils continues to contribute to its enrichment in estuarine sediments. Concentrations of other elements (e.g., Cu, Zn, Cd), however, have not decreased with time, suggesting continued active inputs. Concentrations of Ba, Co, Cr, Ni, V and U, although elevated in some cases, typically reflect greater proportions attributed to natural sources rather than anthropogenic input. 相似文献
4.
Eric Heinen De Carlo Michael S. Tomlinson Stephen S. Anthony 《Applied Geochemistry》2005,20(12):2157-2188
Data are presented for trace element concentrations determined in the <63 μm fraction of streambed sediment samples collected at 24 sites on the island of O‘ahu, Hawai‘i. Sampling sites were classified as urban, agricultural, mixed (urban/agricultural), or forested based on their dominant land use, although the mixed land use at selected sampling sites consisted of either urban and agricultural or forested and agricultural land uses. Forest dominated sites were used as reference sites for calculating enrichment factors.Trace element concentrations were compared to concentrations from studies conducted in the conterminous United States using identical methods and to aquatic-life guidelines provided by the Canadian Council of Ministers of the Environment. A variety of elements including Pb, Cr, Cu and Zn exceeded the aquatic-life guidelines in selected samples. All of the Cr and Zn values and 16 of 24 Cu values exceeded their respective guidelines. The potential toxicity of elements exceeding guidelines, however, should be considered in the context of strong enrichments of selected trace elements attributable to source rocks in Hawai‘i, as well as in the context of the abundance of fine-grained sediment in the streambed of O‘ahu streams.Statistical methods including cluster analysis, Kruskal–Wallis non-parametric test, correlation analysis, and principal component analysis (PCA) were used to evaluate differences and elucidate relationships between trace elements and sites. Overall, trace element distributions and abundances can be correlated to three principal sources of elements. These include basaltic rocks of the volcanic edifice (Fe, Al, Ni, Co, Cr, V and Cu), carbonate/seawater derived elements (Mg, Ca, Na and Sr), and elements enriched owing to anthropogenic activity (P, Sn, Cd, Sn, Ba and Pb). Anthropogenic enrichment gradients were observed for Ba, Cd, Pb, Sn and Zn in the four streams in which sediments were collected upstream and downstream.The findings of this study are generally similar to but differ slightly from previous work on sediments and suspended particulate matter in streams, from two urban watersheds of O‘ahu, Hawai‘i. Inter-element associations in the latter were often stronger and indicated a mixture of anthropogenic, agricultural and basaltic sources of trace elements. Some elements fell into different statistical categories in the two studies, owing in part to differences in study design and the hydrogeological constraints on the respective study areas. 相似文献
5.
Heavy metals content and distribution in the surface sediments of the Guangzhou section of the Pearl River,Southern China 总被引:2,自引:2,他引:0
The long-term industrialization and urbanization of Guangzhou city may lead to heavy metal contamination of its aquatic sediment.
Nevertheless, only few studies have been published on the distribution and contamination assessment of heavy metals in this
urban river sediment. Thus, the major objective of this study was to quantitatively assess contamination of heavy metals and
their chemical partitioning in the sediments of the Guangzhou section of the Pearl River (GSPR). Surface sediment samples
were collected at 10 sites in the main river and 12 sites in the creeks of the GSPR. The total content of Cd was determined
by graphite furnace atomic adsorption spectrometry (GF-AAS), and content of Cr, Cu, Pb and Zn was determined by inductively
coupled plasma atomic emission spectrometry (ICP-AES). The chemical partitioning of these heavy metals in the sediments of
the main river was determined by the sequential selective extraction (SSE) method. Results indicated that the average total
concentrations of Cd, Cr, Pb, Cu and Zn in the sediments of the main river were 1.44, 63.7, 95.5, 253.6 and 370.0 mg/kg, respectively,
whereas they were 2.10, 125.5, 110.1, 433.7 and 401.9 mg/kg in the sediments of the creeks. The sediment at M4 and C9 sites
was heavily contaminated with about 8 and 11 of toxic unit, respectively. Cr, Cu, Pb and Zn were mostly bound to organic matter
and in the residual phase, whereas Cd was mostly associated with the soluble and exchangeable phase and the residual phase.
The mobility and bioavailability of Cd, Zn and Cr in the sediments of the main river were relatively higher than Cu and Pb,
due to higher levels in the soluble and exchangeable fraction and the carbonate fraction. The potential acute toxicity in
the sediments of the main river and creeks was mainly caused by Cu contamination, accounting for 21.7–37.1% and 16.9–46.3%
of the total toxicity, respectively, followed by Zn and Pb. Adverse biological effects induced by heavy metals would be expected
in the sediments of the GSPR. Therefore, the sediments of the GSPR, especially at M4 and C9 sites, need to be remediated to
maintain aquatic ecosystem health. 相似文献
6.
The marine coastal sediments from Togo have been analysed for the trace elements Cd, Cr, Cu, Ni, Pb, Sr, V, Zn and Zr to
ascertain the geo-ecological impact of dumping of phosphorite tailings into the sea. Trace element concentrations ranged from
2–44 ppm for Cd, 22–184 ppm for Cu, 19–281 ppm for Ni, 22–176 ppm for Pb, 179–643 ppm for Sr, 38–329 ppm for V, 60–632 ppm
for Zn and 18–8928 ppm for Zr. Regional distribution of trace elements in the marine environment indicates that the concentrations
of Cr, Cu, Ni, Pb, V, Sr and Zn increase seawards and along the coastal line outwards of the tailing outfall, whereas Cd and
Zr showed reversed spatial patterns. Sorting and transport of phosphorite particles by coastal currents are the main factors
controlling the distribution of particle-bound trace metals in the coastal environment. The Cd, Sr and Zn concentrations decrease
with decreasing grain size in marine coastal sediments, whereas Cr, Cu, Ni and Zn concentrations increase with decreasing
grain size. Percolation and shaking experiments were carried out in laboratory using raw phosphate material and artificial
sea water. Enhanced mobilization of Cd from phosphorites by contact with the sea water was observed.
Received: 11 May 1998 · Accepted: 20 October 1998 相似文献
7.
Seasonal and spatial dynamics of trace elements in water and sediment from Pearl River Estuary, South China 总被引:2,自引:2,他引:0
Dawen Zhang Xia Zhang Lei Tian Feng Ye Xiaoping Huang Yanyi Zeng Minling Fan 《Environmental Earth Sciences》2013,68(4):1053-1063
In this study, spatial and seasonal dynamics of trace elements (Cu, Pb, Zn, Cd, As) in water and sediments were examined in the Pearl River Estuary (PRE), South China. The spatial variations of all the studied trace elements in sediments show the general decrease pattern from northwest to southeast side of the PRE, suggesting that the main sources of these trace elements may originate from terrestrial (rock and soil) weathering and human activities (e.g. agricultural, industrial and municipal wastewaters) via riverine inputs. The dissolved Cu, Pb, Cd, As, and Zn in PRE ranged from 0.34 to 3.26, 0.19 to 4.58, 0.0015 to 0.30, 0.16 to 8.18, 3.74 to 36.10 μg/L, respectively. There are obvious seasonal changes of dissolved trace elements in the PRE aquatic system. The maximum seasonal averages of all the dissolved trace elements excluding Zn were observed in summer, whereas dissolved Zn showed the minimum in this season. The overall spatial pattern of all the dissolved trace elements excluding Zn demonstrates decreasing trends from inshore to offshore, and the highest concentrations of dissolved Cu, Cd, As, and Zn appeared in the western part of PRE or the mouths of Pearl River, suggesting strong riverine and anthropogenic local inputs. PCA and correlation analysis show that the geochemical behavior of dissolved Cu and As are complicated and the dynamics of these two elements are controlled by various physicochemical parameters, whereas physicochemical parameters might play a relatively small role in the distributions of other studied trace elements. 相似文献
8.
Partitioning,bioavailability and origin of heavy metals from the Nador Lagoon sediments (Morocco) as a basis for their management 总被引:2,自引:0,他引:2
Nador Lagoon sediments show low trace element concentrations, and, in relation to the lagoon geochemical baseline, only some
anomalies for As, Cd, Cu and Pb in the NW of the lagoon deserve to be outstanding. The distribution of major, minor and trace
elements in the lagoon allows a breakdown in four zones. Between “Beni Ensar” and “Atelouane” (zone A), a quite confined zone
rich in organic matter and S, the most important trace-element anomalies (As, Cd, Co, Cu, Mn, Pb, Zn) were found, mainly around
industry and old mining activities. In the surrounding of the city of Nador (zone B), the anomalies correspond to Mn, Cu and
Zn. The coastal barrier and Kebdana channel (zone C) show moderately concentrations of Cd, Cr and Ni at specific sites. The
less polluted area is the SE of the lagoon (zone D), with no outstanding anomaly. In lagoon sediments, metal bioavailability
is very low. The metal partitioning patterns show that Cu, Pb and Zn present a low availability because they are bounded to
the residual, non-mobile phases of the sediments. Only in some sites, the fraction was associated with organic matter, which
could be liberated easily. Arsenic is concentrated in both the residual phases and the organic matter, the latter being more
available. Cadmium is mainly concentrated in some samples in the interchangeable fraction, which could be considered as a
potentially toxic element because it is easily released. Concerning the origin of these trace elements, those found in zone A
correspond mostly to a natural source by weathering of mount Gourougou volcanic rocks (As, Co, Cu, Pb and Zn), and to an anthropogenic
origin (Cd) owing to the presence of industry and old mines. In zone B, contributions of Cu and Zn enter the lagoon through
soil weathering and river-borne, and as anthropogenic pollution from urban wastes. In zone C the most important pollutant
is Cd deduced to be of anthropogenic origin from the close industry and intensive agriculture area. In spite of the intense
socio-economic activities developed in the Nador Lagoon (agriculture, industry, fishing, tourism) trace element concentrations
in the sediments are low and with scarce bioavailability. Only the NW sector is relativity polluted because of geogenic features. 相似文献
9.
Cr, Cu, Fe, K, Mg, Mn, N, Ni, Pb, S, V and Zn concentrations were determined during a whole seasonal cycle in leaves and in water and sediment roots of the aquatic macrophyte Phragmites australis (Cav.) Trin. ex Steudel from three sites in the Lake Averno (Naples, Italy), a volcanic lake contaminated by trace elements. At the beginning of the research, elemental analysis was also performed on lake sediments, that showed different trace-element concentrations depending on the sites. 相似文献
10.
Ibtehal Fathy Mohamed 《Arabian Journal of Geosciences》2013,6(11):4145-4153
The heavy metal contents of Mn, Ni, Cu, Zn, Cr, Co, Pb, Cd, Fe, and V in the surface sediments from five selected sites of El Temsah Lake was determined by graphite furnace atomic absorption spectrophotometer. Geochemical forms of elements were investigated using four-step sequential chemical extraction procedure in order to identify and evaluate the mobility and the availability of trace metals on lake sediments, in comparison with the total element content. The operationally defined host fractions were: (1) exchangeable/bound to carbonate, (2) bound to Fe/Mn oxide, (3) bound to organic matter/sulfides, and (4) acid-soluble residue. The speciation data reveals that metals Zn, Cd, Pb, Ni, Mn, Cu, Cr, Fe, and V are sink primarily in organic and Fe–Mn oxyhydroxides phases. Co is mainly concentrated in the active phase. This is alarming because the element is enriched in Al Sayadin Lagoon which is still the main site of open fishing in Ismailia. Average concentration of the elements is mostly above the geochemical background and pristine values of the present study. There is a difference on the elemental composition of the sediment collected at the western lagoon (Al Sayadin Lagoon), junction, the shoreline shipyard workshops, and eastern beach of the lake. Depending upon the nature of elements and local pollution source, high concentration of Zn, Pb, and Cu are emitted by industrial wastewater flow (shoreline workshops), while sanitary and agricultural wastewater (El Bahtini and El Mahsama Drains) emit Co and Cd in Al Sayadin Lagoon. On the other hand, there is a marked decrease in potentially toxic heavy metal concentrations in the sediments at the most eastern side of the lake, probably due to the successive sediment dredging and improvements in water purification systems for navigation objective. These result show that El Temsah receives concentrations in anthropogenic metals that risk provoking more or less important disruptions, which are harmful and irreversible on the fauna and flora of this lake and on the whole ecobiological equilibrium. 相似文献
11.
12.
为探讨渤海西部在多重环境因素变化下沉积物中重金属的环境地球化学行为,分析了渤海西部44个站位表层沉积物样品中8种重金属元素含量,研究了重金属元素的分布特征、环境影响因素及其生态风险。结果表明,渤海西部表层沉积物中As、Cu、Cd、Cr、Hg、Ni、Pb、Zn的平均含量分别为117 mg/kg、255 mg/kg、014 mg/kg、689 mg/kg、0037 mg/kg、303 mg/kg、223 mg/kg、757 mg/kg;Cu、Cr、Ni、Zn含量与有机碳含量、小于63 μm细粒沉积物呈显著正相关,其在表层沉积物中的分布明显受到有机质含量和沉积物粒径的控制,而As、Hg分布没有明显受到有机质含量的影响。富集系数显示,Cr、Ni、Pb和Zn为无富集,Cu、As为轻度富集,Cd和Hg为中度富集。与多种背景值和一致性沉积物质量基准相比较,渤海西部表层沉积物Pb、Cd的含量超出背景值,而Cu、Zn、Ni、Cr、As、Hg含量也存在一定的异常,但其含量水平引发有害生物效应的可能性不大,尽管重金属元素含量偏高,但生态风险较小。 相似文献
13.
Heavy metals in freshly deposited sediments of the Gomati River (a tributary of the Ganga River): effects of human activities 总被引:10,自引:0,他引:10
The concentrations of various metals (Cr, Cu, Co, Fe, Mn, Ni, Pb, Zn, and Cd) were determined in recently deposited surface
sediments of the Gomati River in the Lucknow urban area. Markedly elevated concentrations (milligrams per kilogram) of some
of the metals, Cd (0.26–3.62), Cu (33–147), Ni (45–86), Pb (25–77), and Zn (90–389) were observed. Profiles of these metals
across the Lucknow urban stretch show a progressive downstream increase due to additions from 4 major drainage networks discharging
the urban effluents into the river. The degree of metal contamination is compared with the local background and global standards.
The geoaccumulation index order for the river sediments is Cd>Zn>Cu>Cr>Pb. Significant correlations were observed between
Cr and Zn, Cr and Cu, Cu and Zn and total sediment carbon with Cr and Zn. This study reveals that the urbanization process
is associated with higher concentrations of heavy metals such as Cd, Cu, Cr, Pb, and Zn in the Gomati River sediments. To
keep the river clean for the future, it is strongly recommended that urban effluents should not be overlooked before their
discharge into the river.
Received: 16 February 1996 · Accepted: 29 February 1996 相似文献
14.
Assessing the current state of the Gironde Estuary by mapping priority contaminant distribution and risk potential in surface sediment 总被引:1,自引:0,他引:1
Aurlie Larrose Alexandra Coynel Jrg Schfer Grard Blanc Laurent Mass Eric Maneux 《Applied Geochemistry》2010,25(12):1912-1923
Based on high spatial resolution monitoring, the first spatial distribution maps for the eight trace elements identified as priority contaminants in aquatic systems (i.e. As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in surface sediments of the Gironde Estuary (SW France) are presented. This large European fluvial–estuarine system is known for important historical multi-element (mainly Cd, Zn, Cu and Pb) pollution by former mining and mineral processing activation in the Riou-Mort watershed located 350 km upstream the estuary. As a consequence, oyster production in the estuary is prohibited, and Cd concentrations in oysters from the Marennes-Oléron area are close to consumption thresholds. Surface sediment samples were analysed for grain size, particulate organic C and trace element concentrations. Determination of trace elements was carried out by ICP-MS for As, Cd, Cr, Cu, Ni, Pb, Th and Zn, and by CV-AAS for Hg. Total and potentially released trace element stocks in the surface sediment were evaluated by using concentrations in the estuary and in selected sediment core. Assuming that sediment resuspension affects mainly the uppermost sediment layer, the total trace element stocks in the studied 0–10 cm depth range may represent the equivalent of one (Cd) to eight (As, Cr) times the annual fluvial trace element inputs into the estuary. Comparing total trace element concentrations in surface sediment with: (i) data on the regional geochemical baseline to evaluate the potentially remobilised fraction and (ii) the potentially bioavailable fraction aimed at establishing a first spatially resolved risk assessment of the trace element “cocktail” present in these sediments at the estuary scale. After correction for grain size effects by Th normalisation, potentially highly toxic metals such as Cd and Hg showed the highest enrichment factors. From ecotoxicological indices, areas were identified and quantified where trace element levels and mobility may bear a risk to benthic organisms. The GIS-based spatial distribution of ecotoxicological indices for the trace element “cocktail” suggests that ∼95% of the surface sediment are ‘Low–Medium’-priority zones, highlighting the need for further impact studies. The produced maps of trace element distributions and associated risk potentials are likely to be a useful tool to authorities in charge of sustainable estuarine management, e.g. for the optimisation of dredging activities or development of the estuarine infrastructure. 相似文献
15.
Temporal and spatial patterns of trace elements in the Patuxent River: A whole watershed approach 总被引:1,自引:0,他引:1
Gerhardt F. Riedel Sherry A. Williams Georgia S. Riedel Cynthia C. Gilmour James G. Sanders 《Estuaries and Coasts》2000,23(4):521-535
Trace element distributions, partitioning, and speciation were examined at 15 sites in the Patuxent River watershed from May 1995 through October 1997 to determine possible sources of trace elements to the river and estuary, to examine the relationship of the trace element discharges to freshwater discharges as well as to land use and geographic region, to validate previous estimates of loadings to the river, and to provide baseline data for trace elements in the Patuxent River watershed and estuary. Six freshwater sites were examined, representing different basins and geographic provinces, and nine sites along the estuarine salinity gradient. Subregions within the watershed varied considerably in concentrations and areal yields for some elements. Concentrations of As, Cd, Ni, Pb, and Zn were elevated in the Coastal Plain sites compared to the Piedmont sites, while Cu and Hg were more evenly distributed. Cadmium, Cu, Hg, Ni, Pb, and Zn showed overall positive correlations with river flow while As and methylHg (meHg) showed negative correlations with river flow. Concentrations of trace elements in the estuarine portion of the river were generally low, and consistent with mixing between Patuxent River water with elevated concentrations and the lower concentrations of the Chesapeake Bay. Interesting features included a local Cd maximum in the low salinity region of the estuary, probably caused by desorption from suspended sediments, and a significant input of water containing high As concentrations from the Chesapeake Bay and from As being released from bottom sediments in summer. Comparisons between the estimated annual flux of trace elements and the estimates of suspected source terms (atmospheric deposition, urban runoff, and known point sources) suggest that, except for Hg, direct atmospheric deposition is small compared to fluvial loads. Current estimates of trace element inputs from point sources or from urban runoff are inadequate for comparison with other sources, because of inappropriate techniques and/or unacceptably high detection limits. A complete examination of trace element dynamics in the Patuxent River (and in other coastal systems) will require better data for these potential sources. 相似文献
16.
This study provided a picture of the spatial and temporal distributions of Cr, Co, Ni Cu, Zn, As, Cd and Pb in bottom sediments
of Tolo Harbour. The concentrations of the eight heavy metals differed significantly between sites due to the poor tidal flushing
in Tolo Harbour. The levels of Cu, Zn, Cd and Pb were generally enriched in sediments from inner Tolo Harbour, while sediments
from outer Tolo Harbour (Tolo Channel) had higher levels of Cr, Co and Ni. The redox sensitive element arsenic showed no distinct
spatial pattern in Tolo Harbour. The decreasing levels of Cu, Zn, Pb and Cd in sediments with increasing distance from land
demonstrated a typical diffusion pattern from land to the direction of sea. Two hot spots of Cu, Zn, Pb and Cd in sediments
were located near Tai Po and Sha Tin new town, indicating that Cu, Zn, Pb and Zn were from land-derived sources. The sites
with relatively high levels of Cr, Co and Ni in sediments were located in areas close to waste spoil in sea floor. The natural
and anthropogenic inputs from Sha Tin and Tai Po to Tolo Harbour were mostly responsible for Cu, Zn, Cd and Pb enrichment
in sediments from inner Tolo Harbour. The waste spoil in sea floor was believed to contribute to the Cr, Co and Ni in outer
Tolo Harbour. The results of correlation coefficient between the eight heavy metals showed that Cu, Zn, Cd and Pb were strongly
positively correlated, and Cr, Co and Ni were also significantly correlated with each other. The best explanation of strong
correlation was their similar source. As, however, is not well correlated with the other seven heavy metals. The average concentrations
of Cu and Zn displayed general increasing trends from 1978 to 2006 in Tolo Harbour, while the mean levels of Cr and Pb displayed
a substantial decrease from 1978 to 1987, then a slight increase after 1987. No distinct temporal trends of the concentrations
of Ni and As were observed from 1978 due to the inconsecutive data. On the other hand, the increasing trends of Cr, Cu, Zn,
Cd and Pb were observed since 1996. 相似文献
17.
Lan Wang Yaping Wang Wenzhao Zhang Chunxue Xu Ziyi An 《Environmental Earth Sciences》2014,71(3):1183-1193
The concentrations of heavy metals (Cr, Co, Ni, Cu, Zn, Pb, Cd, As, Hg, and Fe) in sediments of the Yangtze River, China, were investigated to evaluate levels of contamination and their potential sources. The lowest heavy metal concentrations were found in the source regions of the river basin. Relatively high concentrations of metals, except Cr, were found in the Sichuan Basin, and the highest concentrations were in the Xiangjiang and Shun’anhe rivers. All concentrations, except Ni, were higher than global averages. Principal component analysis and hierarchical cluster analysis showed that Zn, Pb, As, Hg, and Cd were derived mainly from the exploitation of various multi-metal minerals, industrial wastewater, and domestic sewage. Cu, Co, and Fe were derived mainly from natural weathering (erosion). Cr and Ni were derived mainly from agricultural activities, municipal and industrial wastewater. Sediment pollution was assessed using the geoaccumulation index (I geo) and enrichment factor (EF). Among the ten heavy metals assessed, Cd and Pb had the highest I geo values, followed by Cu, As, Zn, and Hg. The I geo values of Fe, Cr, Co, and Ni were <0 in all sediments. EF provided similar information to I geo: no enrichment was found for Cr, Co, and Ni. Cu, Zn, As, and Hg were relatively enriched at some sites while Cd and Pb showed significant enrichment. 相似文献
18.
《Applied Geochemistry》2003,18(3):409-421
This study provides a geochemical partitioning pattern of Fe, Mn and potentially toxic trace elements (As, Cd, Cr, Cu, Ni, Pb, Zn) in sediments historically contaminated with acid mine drainage, as determined by using a 4-step sequential extraction scheme. At the upperstream, the sediments occur as ochreous precipitates consisting of amorphous or poorly crystalline oxy-hydroxides of Fe, and locally jarosite, whereas the estuarine sediments are composed mainly of detrital quartz, illite, kaolinite, feldspars, carbonates and heavy minerals, with minor authigenic phases (gypsum, vivianite, halite, pyrite). The sediments are severely contaminated with As, Cd, Cu, Pb and Zn, especially in the vicinity of the mining pollution sources and some sites of the estuary, where the metal concentrations are several orders of magnitude above background levels. Although a significant proportion of Zn, Cd and Cu is present in a readily soluble form, the majority of heavy metals are bonded to reducible phases, suggesting that Fe oxy-hydroxides have a dominant role in the metal accumulation. In the estuary, the sediments are potentially less reactive than in the riverine environment, because relevant concentrations of heavy metals are immobilised in the crystalline structure of minerals. 相似文献
19.
为了解大亚湾表层沉积物中重金属的污染状况,对大亚湾海域23个点位表层沉积物中7种重金属元素(Cr、Ni、Cu、Pb、Zn、Cd、As)的质量分数、形态特征、来源控制因素以及潜在生态风险进行了研究。采用优化BCR提取法分析重金属元素赋存形态,并依据各种重金属元素的形态特征与沉积物基质属性进行了相关因子分析,了解其分布的控制因素。结果表明:大亚湾沉积物重金属元素呈现环带状分布特征,从岸向湾内逐渐减小;重金属元素质量分数的高值区主要分布于大鹏澳、哑铃湾及范和港附近;重金属元素赋存形态中Cr、Ni、Cu、Zn、As主要以残渣态存在,Pb主要以可还原态存在,Cd主要以酸提取态存在;7种重金属元素各自非残渣态所占比率从大到小为Pb(78.83%)、Cd(78.65%)、Cu(48.54%)、Zn(48.10%)、Ni(38.31%)、Cr(28.43%)、As(27.76%),即Pb最高,As最低,表明Pb的迁移性最强;通过因子分析,大亚湾重金属主要为沿岸自然风化产物的输入,其次为工业废水及养殖污水。运用酸提取态风险评估法对重金属元素潜在生态风险进行评价,发现研究区所选重金属元素综合风险评价Cd为高风险,其余重金属为中-低风险等级。 相似文献
20.
Geochemical and statistical analysis of trace metals in atmospheric particulates in Wuhan, central China 总被引:3,自引:0,他引:3
Weiwei Lv Yanxin Wang Xavier Querol Xinguo Zhuang Andrés Alastuey Angel López Mar Viana 《Environmental Geology》2006,51(1):121-132
The geochemical characteristics of trace metals (As, Cr, Co, Cd, Cu, Mn, Ni, Pb, V and Zn) in PM10 in Wuhan, the biggest metropolitan in central China, as well as their sources and contributions were analyzed. As PM10 has been the principal contaminant of air in Wuhan for years, concentrations of trace metals were measured in PM10 using high-volume samplers at one urban (Hankou) and one industrial (Changqian) site in Wuhan between September 2003 and September 2004. Based on the results, PM10 in Wuhan is characterized by relatively high levels of As, Cd, Mn, Pb and Zn compared with other Asian cities. The time-series of these elements indicated that As, Cu and Zn at both sites have similar trends, whereas Pb levels showed different patterns due to different emission sources. Factor analysis was applied to the datasets focusing on the apportionment of the mass of selected trace metals. Results indicate that Pb, Cd and As have a common source (smelting) at both sites, whereas the sources of Ni vary from coal combustion and steel in Changqian to mineral and traffic in Hankou. 相似文献