Heavy metals and metalloids in sediments from the Llobregat basin,Spain

The concentration of heavy metals and metalloids (As, Cd, Cr, Cu, Hg, Ni, Pb, Sb and Zn) in sediments from the River Llobregat and its tributaries (Anoia and Cardener) was studied. Samples collected at 17 locations during four different periods were analysed by ICP-MS. The heavy metal enrichment at some sites along the rivers reflects the effects of agricultural activities, sewage treatment plant effluents, collectors' discharges and industrial activities. Principal component analysis (PCA) was used to describe trends in contamination and to find groupings among the investigated areas. The Llobregat and Cardener sediments appeared to have features of an unpolluted river, even though significant amounts of domestic and industrial wastewater are discharged into these rivers. On the other hand, the sediments from the River Anoia showed high Cr and Hg levels originating from industrial activities. The concentrations of Cr and Hg ranged from 91–540 and 0.28–2.29 µg/g respectively.     

Hydrological and geochemical controls governing the distribution of trace metals in a mine-impacted lake

Factors controlling the distribution of mining-derived Cu, Pb and Zn in the waters and bottom sediments of a large Andean lake (Lago Junin, Peru) have been assessed based on sample collections in May/June 1997 (dry season) and February/March 1998 (wet season). Relatively low levels of trace metals detected in surface waters of the lake during the dry season contrasted greatly with the high values observed during the wet period. Dry season concentrations of total Zn, Cu and Pb in the central lake basin averaged 41, 4.4 and 0.24 µg/L, respectively. In contrast, the respective wet season concentrations of total Zn, Cu and Pb in areas of the main basin ranged up to 387, 52 and 40 µg/L. The seasonal variability in metal concentrations largely reflects an increase in the concentration of particulate metal phases during the wet season. Such observations can be attributed to changes in sediment loadings associated with mining-derived river inputs and changes in lake circulation resulting from hydroelectric dam operations. Surface sediments are characterized by lake-wide enrichments of Zn, Cu and Pb, with maximum concentrations reaching as high as 5, 0.25 and 0.7 wt%, respectively. Estimated rates of authigenic metal accumulation are not sufficient to account for the elevated metal concentrations in the main basin of the lake, indicating that metal distributions are governed by the accumulation of metal-rich particulates. Variations in the spatial distributions of Zn, Cu and Pb are suggested to be a function of varying host phases and textural sorting.     

Environmental assessment of copper–gold–mercury mining in the Andacollo and Punitaqui districts,northern Chile

The Coquimbo region has been one of the richest producers of Cu, Au and Hg in Chile, and some of the deposits have been mined almost continuously since the 16th century. To assess the potential environmental contamination in this region, the authors measured the concentration of Cu, As, Cd, Zn and Hg in samples of stream and mine waters, stream sediments, soils, flotation tailings, and mine wastes in the Andacollo (Cu, Au, Hg) and Punitaqui (Cu–Au, Hg) districts. The concentration of Hg in the atmosphere in these districts were also measured. Although contamination is strongly controlled by the ore in each district, metal dispersion is modified by the degree of metallurgical processing efficiency as shown by the outdated Cu flotation system at Andacollo (stream sediments Cu 75–2200 μg/g). Conversely, more efficient procedures at Punitaqui resulted in less stream contamination, where stream sediments contained Cu ranging from 110–260 μg/g. However, efficient concentration by flotation of a given metal (e.g. Cu) may lead to the loss of another (e.g. Hg up to 190 μg/g in the tailings at Punitaqui), and therefore, to contamination via erosion of the tailings (downstream sediments Hg concentrations up to 5.3 μg/g). Continued use of Hg for Au amalgamation at Andacollo has led to significant contamination in stream sediments (0.2–3.8 μg/g Hg) and soils (2.4–47 μg/g Hg). Communities in this region are underdeveloped, and decades of inefficient treatment of flotation tailings and waste-rock stock piles has resulted in significant contamination of the surrounding landscape.     

Comprehensive analysis of heavy metals in soils from Baoshan District, Shanghai: a heavily industrialized area in China

The potential for soil heavy metal contamination in high risk areas is a crucial issue that will impact the environment. Soil samples were collected in 2003 and 2007 to investigate heavy metal contamination characteristics and pollution changes in the industrialized district of Baoshan (Shanghai, China). Both multi-statistic and geostatistic approaches were used and proved to be useful in the interpretation of the analytical results. The potential for soil contamination in the high risk areas presents a crucial issue that will impact the environment. The results indicate that soil in the Baoshan District is alkaline. Additionally, the accumulation of heavy metals in the soil increased between 2003 and 2007. The study results indicated that the concentration of the metals lead (Pb), chromium (Cr), cadmium(Cd), mercury (Hg), arsenic (As), zinc (Zn) and copper (Cu) in the soil has great discrepancy, especially of Pb and Cr. The concentrations of Pb and Cr in the soil show significant difference between two observed years (p?<?0.05). The concentration of most of these metals was higher in 2007 than 2003. Only the concentrations of Cd and As were not higher in 2007. Traffic and industrial contaminants were the likely source of Pb and As; Hg largely came from agricultural contamination, household garbage and industrial contamination; Cd, Cr, Zn and Cu mainly originated from industrial activities. Multivariate statistical analyses showed that human activities mainly contributed to heavy metal contamination. Spatial distribution confirmed this by showing that areas with the highest metal concentrations occurred where there were high levels of industrial activity and traffic. Potential ecological risk assessment results showed that high risk zones were highly correlated with spatial analysis. The study estimated that in 2007, 85.2?% of the district could be categorized as high risk, which is 77.4 times more than that in 2003.     

Heavy metal accumulation in the surficial sediments along southwest coast of India

Concentration and distribution of heavy metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn) in surface sediments collected from five stations located along the southwest coast of India were investigated seasonally to assess whether there is insidious buildup of heavy metals. Spatial variation was in accordance with textural characteristics and organic matter content. The concentration of the metals in sediments of the study area followed the order: Zn > Cr > Ni > Cu > Pb > Cd > Hg. The use of geochemical tools and sediment quality guidelines to account for the magnitude of heavy metal contamination revealed high contamination in monsoon and impoverishment during post-monsoon. Estimated total metal concentrations in the present investigation were comparable with other studies; however, concentrations of Ni and Zn were higher than that of other coastal regions. Concentrations of metals in sediment largely exceed NOAA effects range:low (e.g., Cu, Cr, Hg) or effects range:median (e.g., Ni) values. This means that adverse effects for benthic organisms are highly probable.     

Mineralogy of metal contaminated estuarine sediments,Derwent estuary,Hobart, Australia: implications for metal mobility

The mobility, bioaccessibility and transfer pathways of metals and metalloids in estuarine sediments have been the focus of much detailed research. However, to date, few studies have examined the mineralogical siting of metals and metalloids in such sediments. This is despite the fact the mineralogy of sediments is an important factor that controls which and how much of a particular metal is released to pore waters and overlying water columns. This study reports on the mineralogical siting of metals in contaminated estuarine sediments, Hobart, Australia, and aims to evaluate the mobility of metals in the contaminated substrates. Mineralogical, mineral chemical and bulk chemical analyses demonstrate that the sediments contain very high levels of several metals and metalloids. The contaminated sediments have concentrations of zinc (Zn), lead (Pb), copper (Cu) and cadmium (Cd) ranging from 0.55 to 4.23 wt%, 0.16 to 0.70 wt%, 415 to 951 mg/kg and 23 to 300 mg/kg, respectively. Franklinite and lesser sphalerite are the main repositories of Zn, whereas much of the Pb and Cu is hosted by sulfides, organic matter and undetermined iron (Fe) oxides. While the release of contaminant loads from franklinite through dissolution is likely to be insignificant, even small releases of metals from the highly contaminated sediments can still cause the deterioration of local water quality. The contaminated sediments represent long-term sources of metal pollutants, particularly Zn, to local waters. This study demonstrates that mineralogical analyses are a vital tool to recognise the potential mobility of trace metals in estuarine environments.     

Heavy metal pollution of coastal river sediments, north-eastern New South Wales, Australia: lead isotope and chemical evidence

 Heavy metal and metalloid concentrations within stream-estuary sediments (<180-μm size fraction) in north-eastern New South Wales largely represent natural background values. However, element concentrations (Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Zn) of Hunter River sediments within the heavily industrialized and urbanized Newcastle region exceed upstream background values by up to one order of magnitude. High element concentrations have been found within sediments of the Newcastle Harbour and Throsby Creek which drains into urbanized and light industry areas. Observed Pb enrichments and low ²⁰⁸Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb and ²⁰⁶Pb/²⁰⁴Pb ratios are likely caused by atmospheric deposition of Pb additives from petrol and subsequent Pb transport by road run-off waters into the local drainage system. Sediments of the Richmond River and lower Manning, Macleay, Clarence, Brunswick and Tweed River generally display no evidence for anthropogenic heavy metal and metalloid contamination (Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Zn). However, the rivers and their tributaries possess localized sedimentary traps with elevated heavy metal concentrations (Cu, Pb, Zn). Lead isotope data indicate that anthropogenic Pb provides a detectable contribution to investigated sediments. Such contributions are evident at sample sites close to sewage outlets and in the vicinity of the Pacific Highway. In addition, As concentrations of Richmond River sediments gradually increase downstream. This geochemical trend may be the result of As mobilization from numerous cattle-dip sites within the region into the drainage system and subsequent accumulation of As in downstream river and estuary sediments. Received: 5 September 1997 · Accepted: 4 November 1997     

Metals in the river waters of Primorye

New data are presented on the contents of Fe, Mn, Zn, Cu, Pb, Cd, and Ni in dissolved and particulate modes of occurrence in unpolluted or anthropogenically contaminated major rivers of Primorye. The background contents of dissolved metals are as follows: 0.1–0.5 μg/l for Zn and Ni, 0.3–0.7 μg/l for Cu, 0.01–0.04 μg/l for Pb and Cd, and 2–20 μg/l for Fe and Mn. Common anthropogenic loading (communal wastewaters) notably increases the dissolved Fe and Mn concentrations Industrial wastes lead to a local increase in the contents of dissolved metals in river waters by one to three orders of magnitude. The effect of hydrological regime is expressed most clearly in the areas of anthropogenic impact. The metal contents in the particulate matter are controlled mainly by its granulometric composition. Original Russian Text ? V.M. Shulkin, N.N. Bogdanov, V.I. Kiselev, 2007, published in Geokhimiya, 2007, No. 1, pp. 79–88.     

Partitioning of copper and zinc in the sediments and porewaters of a high-elevation alkaline lake,east-central Arizona,U.S.A.

In Pacheta Lake, a high-elevation alkaline lake proximal to the smelting region of southern Arizona-New Mexico, concentrations of transition metal ions in pore waters and co-existing sediments were compared. Copper, Fe, Mn and Zn have been partitioned among operationally defined sediment solid phases (exchangeable sites, organic complexes, amorphous oxides, crystalline oxides, sulfides and residual silicates) and their concentrations in interstitial waters were measured. Concentrations are reported as a function of depth in the sediment column. The diagenetic environment is described and cycling mechanisms postulated for the above metals.Selective, sequential extraction of metals from lake sediments showed different binding mechanisms for Cu and Zn, the former most strongly associated with organic complexes, and the latter with iron oxyhydroxides. This difference has strong implications for selective metal remobilization under variable environmental conditions, both naturally and anthropogenically induced. Copper and zinc in porewaters were estimated to diffuse to overlying waters at 12.8 and 21.9 μg/cm²/a, respectively. These fluxes are large enough to account for observed concentrations of Cu and Zn in overlying waters. No sediment metal contamination was directly attributable to smelting activity. However, this study does document a flux from sediments, which have accumulated Cu and Zn, to overlying waters no longer receiving trace metal deposition from now inactive smelters.     

Heavy metal contamination in the vicinity of the Daduk Au–Ag–Pb–Zn mine in Korea

The heavy metal contamination and seasonal variation of the metals in soils, plants and waters in the vicinity of an abandoned metalliferous mine in Korea were studied. Elevated levels of Cd, Cu, Pb and Zn were found in tailings with averages of 8.57, 481, 4,450 and 753 mg/kg, respectively. These metals are continuously dispersed downstream and downslope from the tailings by clastic movement through wind and water. Thus, significant levels of the elements in waters and sediments were found up to 3.3 km downstream from the mining site, especially for Cd and Zn. Enriched concentrations of heavy metals were also found in various plants grown in the vicinity of the mining area, and the metal concentrations in plants increased with those in soils. In a study of seasonal variation on the heavy metals in paddy fields, relatively high concentrations of heavy metals were found in rice leaves and stalks grown under oxidizing conditions rather than a reducing environment (P<0.05).     

Contamination of the biological compartment in the Seine estuary by Cd, Cu, Pb, and Zn

A study of contamination of the biological compartment of the Seine estuary was carried out by measuring the concentrations of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in 29 estuarine and marine species belonging to 6 phyla. Species came from three main biological zones of the estuary: the Seine channel (copepods, mysids, shrimps, and fish), the intertidal mudflats (Macoma balthica community), and the subtidal mudflats (Abra alba community). Two fish species, the bass (Dicentrarchus labrax) and the flounder (Platichthys flesus), were also selected for analyses. A comparison of metal concentrations in estuarine species of the Seine with those found in the same species collected on contaminated and non-contaminated sites showed a contamination of the estuary by Cu, Zn, and Pb. For Cd, the contamination is mainly observed in bivalves, although the concentrations observed were low and less than 2 μg g^?1 d.w. High concentrations of Cu were found in copepods, shrimps, and fish. Pb contamination was mainly found in species living in the Seine channel where the copepodEurytemora affinis shows an average concentration of 22 μg g^?1 d.w. High concentrations of Pb (>10 μg g^?1 d.w.) were found in deposit-feeders benthic invertebrates. Elevated levels of Zn were seen in all species collected in the Seine estuary, including fish and in particular small flounder. The concentrations of Cd, Cu, Pb, and Zn found in edible estuarine species (shrimp and fish) were in the same order of magnitude than those found in fish and shrimps fished along the French coast.     

Comparative zinc dynamics in Atlanta metropolitan region stream and street runoff

Zinc, major ion, and other trace metal (V, Cr, Co, Ni, Cu, Cd, and Pb) concentrations were measured within 172 street and stream runoff samples in the Atlanta metropolitan region and in relatively undeveloped watersheds within the Georgia Piedmont and Blue Ridge Provinces. Peachtree Creek, draining a densely populated area of Atlanta, was the primary sampling location and samples were acquired under a wide range of hydrological conditions. Zinc concentrations within street runoff [median (Zn)_{urban street runoff}=905 µg/l] were significantly greater than zinc concentrations within storm runoff [median (Zn)_{Peachtree Creek}=60 µg/l], which were, in turn, greater than zinc concentrations within non-storm runoff [median (Zn)_{Peachtree Creek}=14 µg/l]. Zinc concentrations were not significantly greater within urban base flow than within non-urban base flow, indicating that the primary source of pollution is "event water" or street runoff. Zinc was the only heavy metal present in greater than "background" concentrations (i.e., >10 µg/l), which is likely the result of automotive pollution that is omnipresent within the study area. Analysis of storm alkalinity dilution trends indicate that simple mixing between polluted street runoff and groundwater cannot account for the zinc concentrations observed within storm and recession flows. A two end member mass balance model suggests that a large proportion of the zinc present in the street runoff is adsorbed and transported on surfaces of the suspended sediment. Adsorption is readily possible at the near neutral pH (~6.5) of turbid storm discharge.     

Spatial and seasonal variation of potential toxic elements in Adocia pigmentifera,seawater and sediment from Rameswaram,southeast coast of India

The concentrations of potential toxic elements (PTEs) such as cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) were measured in five different stations of Rameswaram (RM) coast, Gulf of Mannar (GoM), India, in coastal waters in sediments and tissues of Adocia pigmentifera. Concentration of PTEs (Cd, Cu, Pb and Zn) was found to be highest in sediments followed by A. pigmentifera and seawater samples collected from the different stations of RM coast. The pattern of accumulation of PTEs in the three sample types is of the following order Zn < Pb < Cu < Cd. The seasonal variation of these PTEs also followed the same pattern. One-way analysis of variance (ANOVA) with Tukey’s HSD post hoc test has revealed significant differences among stations S1–S4 when compared with the station S5 which is considered as the reference site. Correlation coefficient study showed no significant correlation in the concentration of PTEs in A. pigmentifera, seawater and sediment samples. The concentration of all the PTEs in different sample types has exceeded the FAO/WHO/sediment background values, except for the concentration of Zn in A. pigmentifera and sediment sample, which did not exceed the limits. The contamination factor (CF) and geoaccumulation index (I _geo) values indicated significant contamination of PTEs in the sediments from different stations of RM coast, India. Variations found between the sample types during the studies could be due to changes in levels of pollution discharge over time, availability of PTEs for adsorption as well as variations in the sampling season. Increasing urban sprawl and release of effluents both from domestic and industrial sources are the main sources of pollution at RM coast and are the prime reasons for the loss of existing diverse ecosystem.     

Heavy metal distribution and accumulation in the <Emphasis Type="Italic">Spartina alterniflora</Emphasis> from the Andong tidal flat,Hangzhou Bay,China

In order to study the heavy metal accumulation and distribution in the roots, stems, and leaves of Spartina alterniflora, we collected S. alterniflora samples and the associated sediments along three transects at the Andong tidal flat, Hangzhou Bay. Co, Ni, Cd, Pb, Cu, and Zn were mainly accumulated in the aerial parts (stems and leaves) of the plants, and their distributions depended on their mobility and their roles during the metabolism processes of S. alterniflora. The concentrations of Cu, Zn, Cd, Hg, and Pb were significantly enhanced with the increasing of heavy metal concentrations in the sediments, while those of Co and Ni remained relatively constant. Bioaccumulation factors results showed that the serious heavy metal contamination in the sediments from the transect A may overwhelm the accumulation capability of the plants. In addition, the physicochemical properties of the sediments and the pore water therein also play a role in the heavy metal concentrations and accumulations in the plants, because they can influence the behaviors and bioavailabilities of heavy metals during nutrition and bioaccumulation processes of the plants. The sediments with vegetation did not show significantly decreased heavy metal concentration with respect to the unvegetated sediments, although the plants did absorb heavy metals from the sediments. Principal component analysis and correlation analyses indicated that Co–Ni, Cu–Cd–Hg behaved coherently during accumulation, which may be ascribed to their similar accumulation mechanisms. This work provided essential information on the heavy metal accumulation by plants in a tidal flat, which will be useful for the environmental control through phytoremediation at estuaries.     

Multivariate statistical techniques for evaluating and identifying the environmental significance of heavy metal contamination in sediments of the Yangtze River, China

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.     

Searching of toxic metal pollution by using geospatial technology on the Kodaikanal Lake—near industrial area

The present study investigates the anthropogenic metal input into the lake system, the toxic metal pollution in the sediments of Kodaikanal Lake. Surface sediment samples were collected at seven locations to represent its spatial variability within the lake. Samples were subjected to analyze for Fe, Co, Cr, Mn, Ni, Zn, Cd, Cu, Ag, Pb, Hg, and As by energy dispersive X-ray fluorescence (EDXRF) and their concentrations in lake sediments range from 102,000–109,000, 561–2699, 292–544, 211–482, 79–163, 57–265, 57–74, 37–92, 46–59, 20–97, 19–30, to 13–24 mg/kg, respectively. The sources of pollution were inferred through spatial and statistical analyses. Most of the toxic metal contents in the sediments are found to exceed the background concentration in all locations. The enrichment factor (EF) and index of geoaccumulation (I _geo) of Hg, Co, Cd, and Ag showed that sediments of Kodaikanal Lake exhibit the probability of anthropogenic influence. The significant Pearson’s correlation coefficient is also suggesting that they probably originated from the same source of occurrence. The contamination factor and degree of contamination of the Kodaikanal Lake sediments are strongly polluted in terms of most of the examined metals. The study also provides environmentally significant information about anthropogenic influence on the lake sediments.     

Regional geochemical baseline concentration of potentially toxic trace metals in the mineralized Lom Basin,East Cameroon: a tool for contamination assessment

The distribution of trace metals in active stream sediments from the mineralized Lom Basin has been evaluated. Fifty-five bottom sediments were collected and the mineralogical composition of six pulverized samples determined by XRD. The fine fraction (<?150 µm) was subjected to total digestion (HClO₄?+?HF?+?HCl) and analyzed for trace metals using a combination of ICP-MS and AAS analytical methods. Results show that the mineralogy of stream sediments is dominated by quartz (39–86%), phyllosilicates (0–45%) and feldspars (0–27%). Mean concentrations of the analyzed metals are low (e.g. As?=?99.40 µg/kg, Zn?=?573.24 µg/kg, V?=?963.14 µg/kg and Cr?=?763.93 µg/kg). Iron and Mn have significant average concentrations of 28.325 and 442 mg/kg, respectively. Background and threshold values of the trace metals were computed statistically to determine geochemical anomalies of geologic or anthropogenic origin, particularly mining activity. Factor analysis, applied on normalized data, identified three associations: Ni–Cr–V–Co–As–Se–pH, Cu–Zn–Hg–Pb–Cd–Sc and Fe–Mn. The first association is controlled by source geology and the neutral pH, the second by sulphide mineralization and the last by chemical weathering of ferromagnesian minerals. Spatial analysis reveals similar distribution trends for Co–Cr–V–Ni and Cu–Zn–Pb–Sc reflecting the lithology and sulphide mineralization in the basin. Relatively high levels of As were concordant with reported gold occurrences in the area while Fe and Mn distribution are consistent with their source from the Fe-bearing metamorphic rocks. These findings provide baseline geochemical values for common and parallel geological domains in the eastern region of Cameroon. Although this study shows that the stream sediments are not polluted, the evaluation of metal composition in environmental samples from abandoned and active mine sites for comparison and environmental health risk assessment is highly recommended.     

Metal mobility in alum shale from Öland,Sweden

A study was initiated to analyse metal flows from alum shale to the environment in an area in Öland, Sweden. The study was performed by elemental analysis and leaching experiments of alum shale together with analysis of groundwater and surface water samples.The metal concentrations in non-weathered alum shale were much higher than in weathered or burnt shale, especially for cadmium (Cd), nickel (Ni) and zinc (Zn), indicating a loss of metals during weathering or burning of the shale. The release of metals through weathering was clearly demonstrated by the leaching tests. A 36-week leaching period of non-weathered shale resulted in a drastic drop in pH and a significant increase in metal concentrations in the leachate. The metal concentrations in groundwater were inversely related to the pH. For surface waters, the concentrations of Cd, copper (Cu), Ni and Zn were generally increased compared to background values.In conclusion, metals are released through weathering or burning of alum shale, as well as from heaps of weathered or burnt shale. The release of metals is strongly related to low pH, especially for Cd, Ni and Zn.     

基于GIS技术的江西德兴地区水系沉积物重金属污染的潜在生态危害研究

矿山开发必然对矿区及周边地区的生态环境造成危害。对矿山及其周边地区的生态环境进行现状调查和评价,为生态环境治理客观依据,显得极为重要。在江西德兴地区,系统采集该区域330个水系沉积物样品,并采用X荧光光谱仪和电感耦合等离子原子发射光谱仪为主体的分析配套方案分析样品中重金属的含量基础上,采用潜在生态危害指数法和GIS空间分析技术研究该地区的水系沉积物重金属污染的潜在生态危害。研究结果表明,德兴地区水系沉积物重金属污染的潜在生态危害范围较大,强—很强的生态危害区主要集中德兴铜钼和铅锌矿区、德兴河与大坞河流域及其周边地区,而乐安河下游沿岸以及乐平附近与西北部景德镇附近的少数煤矿区、婺源县城附近和东南角玉山县北西的铜钼矿点附近地区主要为零星中等生态危害。     

Potential ecological risk assessment,enrichment, geoaccumulation,and source identification of metals in the surface sediments of Choghakhor Wetland,Iran

This study reported the first comprehensive research on identification of metal concentrations (Fe, Mg, Mn, Pb, Cd, Cr) in order to provide baseline data for future studies, identify possible sources, determine degree of pollution, and identify potential ecological risks of metals in surface sediments from Iran’s Choghakhor Wetland. The order of metal concentration was as follows: Fe > Mg > Mn > Pb > Cd > Cr, with mean concentrations of 6140.35, 1647.32, 289.03, 1.10, and 0.45 µg/g of dry weight, respectively. These results reveal that Choghakhor Wetland is not heavily polluted compared to other regions. The results of enrichment factor (EF) and geoaccumulation index (I _geo) showed that Fe, Pb, Mg, Cr, and Mn presented low levels of contamination and probably originated from natural sources. On the other hand, the results of EF and I _geo indices suggested that Cd concentrations in sediments of Choghakhor Wetland originated from anthropogenic sources. Based on the results of three sets of sediment quality guidelines, only Cd concentration in sediments of Choghakhor Wetland is a threat for aquatic organisms of Choghakhor Wetland. The results of multivariate analysis such as principal component analysis and cluster analysis showed that Fe–Mn, Cr–Mg, and Pb groups originated from natural sources, while Cd concentrations in sediments of Choghakhor Wetland originated from both natural and anthropogenic sources (mainly chemical fertilizers). To our knowledge, this is the first study about metal concentrations in sediments of Choghakhor Wetland, and because of low levels of these metals, these concentrations can be considered background levels for future investigation.