Metal Concentrations In Surface Sediments Research Articles

Distribution and accumulation of heavy metals in surface sediments from a subtropical bay affected by the Special Economic Zone, China

The concentrations of nine metals (Cd, Cr, Cu, Ni, Mn, Pb, Zn, Fe, and Al) in surface sediments from 14 sampling sites in Shantou Bay were determined in order to understand current metal levels and spatial distribution due to the rapid development of the Shantou Special Economic Zone. Results showed that metal concentrations in surface sediments varied from 0.31 to 1.74 mg kg(-1) for Cd, 35.98 to 74.19 mg kg(-1) for Cr, 24.43 to 79.24 mg kg(-1) for Cu, 428.45 to 809.87 mg kg(-1) for Mn, 16.91 to 31.51 mg kg(-1) for Ni, 35.59 to 64.84 mg kg(-1) for Pb, 84.91 to 246.51 mg kg(-1) for Zn, 2.93 to 3.93% for Fe, and 5.25 to 9.28% for Al. Although all metal concentrations in sediments meet Chinese National Standard Criteria for Marine Sediment Quality, both enrichment factor (EF) and geo-accumulation index (Igeo) show Pb and Cd pollution existed in the upper and middle bay, and pollution of other metals is also recorded in some sites depending on the sources; river input, sewage discharge, and port activities are the main sources of pollutant to the bay.

Assessment and sources of heavy metals in surface sediments of Miyun Reservoir, Beijing

Heavy metals concentrations in surface sediments from Miyun Reservoir were determined to evaluate the pollution and identify the sources. The average content of metals in sediments from Miyun Reservoir followed the order Al>Fe>Ti>Mn>V>Zn>Cr>Ni>Cu>Pb>As>Cd>Hg, and the most mean values were lower than the globe average shale. Heavy metals concentrations at the inflow area of Baihe were higher than those at the inflow area of Chaohe. Heavy metals pollution assessment was carried out by factor enrichment (EF), geoaccumulation index (I(geo)), and potential ecological risk (RI). The EF values for all heavy metals except Hg, Cd, and Cr at several sites were lower than 3, suggesting low anthropogenic impact on the metals level. The I(geo) values of Pb indicated that half of the sites were unpolluted to moderately polluted and mainly located in the Baihe area of the reservoir. The RI showed that heavy metals of Miyun Reservoir were low potential risk, however, Hg approached or belonged to moderate ecological risk at sites of M5, M7, and M13. Correlation analysis and principal component suggested that Ni, Cu, V, Zn, Mn, Cr, Ti, and Pb were derived from soil erosion in upper reaches of the reservoir, while Fe, Cd, Hg, As, and partial Pb originated from anthropogenic sources, particularly industrial mining and gold tailings.

Heavy Metal Sources and Associated Risk in Response to Rapid Urbanization in Surface Sediments of Shantou Bay, South China

Shantou Bay in China is a good example of a site where human pressures and ecological values collide with each other. Twenty eight sediment samples collected from the bay were analyzed for grain size and geochemistry to reveal geochemical sources of selected metals and geochemical processes influencing their distribution, and to assess their enrichment and pollution in the sediments. Results showed that heavy metal concentrations in surface sediments varied from 0.7 mg/kg for Cd to 604.3 mg/kg for Mn. Four geochemical sources were identified as river input, runoff from city, sewage discharge and port pollution by the correlation analysis and principal component analysis. Hydrodynamic condition and input sources are major factors controlling the regional distribution of metals, reflected by a seaward decreasing pattern with some hotspots at the vicinity of river mouths and sewage outlets. Enrichment Factors reveal the anthropogenic sources for Cd, Cu, Zn and Pb. It is supported by the Geo-accumulation Index. The majority of the sediment samples can be occasionally and frequently associated to toxic biological effects, according to the effect-range classification for Cd, Cu, Pb and Zn.

Heavy Metal Concentrations in Surface Sediments and Manila Clams (Ruditapes philippinarum) from the Dalian Coast, China after the Dalian Port Oil Spill

We conducted an investigation of heavy metal concentrations in Manila clams (Ruditapes philippinarum) and surface sediments after the Dalian Port oil spill. Samples were collected from three mariculture zones (Jinshitan, Dalijia, and Pikou) along the Dalian coast. Heavy metal concentrations in R. philippinarum were consistent and ranked in decreasing order of Zn > Cu > As > Cr > Pb > Cd > Hg, while concentrations in surface sediments were ranked as Zn > Cr > Cu > Pb > As > Cd > Hg, respectively. Bioaccumulation of Zn, Cd, and Hg had obviously occurred in R. philippinarum. Statistically significant correlations (p < 0.05) between concentrations of Pb, Cd, and Hg in R. philippinarum and in surface sediments were observed. Except for Cr and As, heavy metal concentrations in R. philippinarum were well within the legal limits for human consumption.

Anthropogenic and natural effects on the water and sediments qualities of costal lagoons: case of the Boughrara Lagoon (Southeast Tunisia)

The Boughrara Lagoon located in southern Tunisia shows evidence of eutrophication and the deterioration of water quality. The large amount of water shown to exchange tidally between the lagoon and the open sea suggests that while water per se is important and observed eutrophication problems are not caused by a lack of water. Heavy metal concentrations in surface sediments of the lagoon indicate that the ecosystem degradation is most likely related to the discharge of untreated phosphogypsum. Excessive pumping from the local freshwater aquifer that previously supplied freshwater to the lagoon via sub-aquatique fractures is likely to be a significant factor contributing to the water and sediment quality degradation of Boughrara Lagoon.

Metal Concentrations in Surface Sediments of Beyler Reservoir (Turkey)

The accumulation of metals (Iron, Aluminium, Zinc, Copper, Manganese, Boron, Chromium, Nickel, Cadmium, Lead) was seasonally (November 2009 to July 2010) measured in sediment samples taken from different areas of Beyler reservoir which is an important water source for irrigation in West Black Sea region (Turkey). Metals in sediment samples were analyzed by ICP-OES. The difference between the stations except for Zn metal (p < 0.05) has not been considered as important and a statistical difference between seasons for Fe, Ni metals (p < 0.01) and Cu metal (p < 0.05) has been observed. The magnitude of metal concentrations in sediment was determined as Aluminium > Iron > Manganese > Zinc > Chromium > Copper > Boron > Nickel > Lead > Cadmium. Enrichment factor (EF) for all metals has been calculated (EF < 1). In the evaluation done by considering the EF values, it is seen that the metal concentrations found in the Beyler Dam Lake sediment stem from the natural composition of the sediment.

Distribution Patterns of Metals Contamination in Sediments Based on Type Regional Development on the Intertidal Coastal Zones of the Persian Gulf, Iran

This study was performed to determine the variation of metals concentrations (Pb, Cd, Zn, and Cu) in surface sediments based on type region development from ten sites on the intertidal coastal zone of the Persian Gulf, Iran. The metals concentrations in surface sediments varied from 0.86 to 180.78μgg(-1) for Pb, 0.61 to 6.48μgg(-1) for Cd, 5.99 to 44.42μgg(-1) for Zn, and 3.01 to 43.33μgg(-1) for Cu. The quality of the sediments was evaluated based on sediment quality guidelines (effects range-low (ERL) and effects range-medium (ERM) indexes. Biological effects criteria suggest that metals concentrations in sediments were lower than ERM for all sites, but for some sites metals concentrations in sediments were higher than ERL. The present results support the concept that human activities in each region could be a major source of metals pollution input in the aquatic environment.

Spatial and temporal variations in trace metal concentrations in surface sediments of the Marennes Oléron Bay. Relation to hydrodynamic forcing

Sediments quality assessment is of priority concern to provide a comprehensible overview of ecological and chemical state of an ecosystem. The Marennes-Oléron Bay, hosting the largest oyster production in France, is influenced by the historic polymetallic pollution of the Gironde Estuary. Despite, management efforts and decreasing emissions in the Gironde watershed, Cd levels in oysters from the bay are close to consumption limit (5 μg g −1 dw, EC no. 466/2001). In this context, the aim of the study was to assess the priority metal (Ni, Cu, Zn, As, Ag, Cd, Hg, Pb and Th) concentrations in sediment within the Bay, by investigating spatial and temporal distribution variations and the role of hydrodynamic forcing. For that we selected three sites (east, west and south) characterizing different environments of the Bay and we observed metal concentrations, grain size distribution, bed elevation and wave activities during a year survey. The sampling strategy pointed out both spatial and temporal metal concentrations variability in sediment. In general, metal enrichments were close to geochemical background. The eastern part of the Bay, largely influenced by the Charente river particulate deposition, presented constant concentrations over the survey. In contrast, in the western part, bed elevation was strongly influenced by hydrodynamic forcing especially wave activities, and metal distribution showed constant metal concentrations except very located Cd minor enrichment related to the Gironde influence via the Antioche Strait (north). The southern part was disconnected from the rest of the Bay and showed minor to very located moderately severe Cd enrichment, related to the Gironde water discharges via the Maumusson Strait (south). Thus, the multi-disciplinary approach was relevant to characterize the interactions between hydrodynamic forcing on the environment and sediments and their metal quality state which (i) were close to geochemical background over a year for Ni, Cu, Zn, As, Ag, Hg and Pb (i) which presented enrichment of Cd in the western and southern part.

Spatial distribution and corresponding determining factors of metal concentrations in surface sediments of Beppu Bay, southwest Japan

This study determined the factors contributing to the spatial distribution of 14 metal concentrations in the surface sediments of Beppu Bay on the basis of comparisons of the organic geochemical properties and environmental parameters through principal component analysis (PCA) and redundancy analysis (RDA). The results of PCA and RDA showed that the concentrations of V, Cr, Co, and As were closely related to the distances between the sampling sites and the Oita River. This indicated that these metals originated from the river’s drainage area. The Mn, Cu, Mo, and Cd concentrations were related to the water depth. These results indicated that the Mo, Cd, and Cu deposition processes were controlled by oxygen depletion, and that these elements accumulated in the deeper parts of the bay under anoxic conditions.

Assessment of heavy metal contamination in Candarli Gulf sediment, Eastern Aegean Sea

Concentrations of selected heavy metals (Fe, Mn, Ni, Cu, Zn, Pb, Hg, Cr, Al, and As) in surface sediments from 18 stations in the Candarli Gulf were studied in order to understand current metal contamination due to urbanization and economic development in Candarli region, Turkey. The sediment samples were collected by box corer in Candarli Gulf in 2009 to assess heavy metal pollution. Heavy metal concentrations in surface sediment varied from 1.62% to 3.60% for Fe, 0.38-2.53% for Al, 173-1,423 for Mn, 8-100 for Ni, 3-46 for Cu, 55-119 for Zn, 16-138 for Pb, 0.2-6.3 for Hg, 16-71 for Cr, and 11-37 mg kg( -1) for As. This study showed that the concentrations of Mn, Ni, Zn, Pb, Hg, and Cr in the surface sediment layers were elevated when compared with the subsurface layers. Both metal enrichment and contamination factors show that Hg, Zn, and Pb contamination exists in the entire study area and contamination of other metals is also present in some locations depending on the sources.

Heavy metal concentrations in surface sediments from two regions (Saros and Gökova Gulfs) of the Eastern Aegean Sea

The main goal of this study is to determine the present heavy metal pollution state in the two gulfs of the Aegean Sea; Saros and Gökova Gulfs. The surface sediments were collected from 11 and eight locations in the Saros and Gökova during May 2001, respectively. The results showed that the sediments of Saros and Gökova gulfs were polluted with Pb, Cr, Zn, Mn, and Ni and Pb, Cr, Ni, and Mn, respectively. For various metals the contamination factor (CF) has been calculated to assess the degree of pollution in sediments. The sediments were noted to be not contaminated with Hg, Cd, and Cu in all areas. Moderate contaminations were observed for Pb, Cr, and Zn in Saros Gulf. The CF was moderate and very high for Ni in the Saros and the Gökova Gulf, respectively.

Heavy metal contamination in western Xiamen Bay sediments and its vicinity, China

Concentrations of selected heavy metals (Cu, Pb, Zn, Cd, Cr, Ni and Fe) in surface sediments from nine sites in western Xiamen Bay and its vicinity were studied in order to understand current metal contamination due to urbanization and economic development in Xiamen, China. The sediment samples were collected in December 2004 and July 2005 respectively in order to examine temporal variations. In this study, we found that heavy metal concentrations in surface sediments sampled in the western Xiamen Bay and adjacent Maluan Bay and Yuandang Lagoon varied from 19 to 97 mg kg −1 for Cu, 45 to 60 mg kg −1 for Pb, 65 to 223 mg kg −1 for Zn, 0.11 to 1.01 mg kg −1 for Cd, 37 to 134 mg kg −1 for Cr, 25 to 65 mg kg −1 for Ni and 3.08 to 4.81% for Fe. Although all metal concentrations in sediments meets Chinese National Standard Criteria for Marine Sediment Quality, both metal enrichment factors (EF) and geoaccumulation index ( I geo) show that Pb contamination exists in the entire study area and contamination of other metals are also present in some locations depending on the sources, of which sewage outlets and commercial ports are the main sources of contaminants to the area. This study shows that using the sediment quality standard criteria only to assess sediments cannot properly reflect sediment contamination. A multiple approaches should be applied for the sediment quality assessment.

Interpretation of anthropogenic input of metals in the South China Sea bottom sediments off Terengganu (Malaysia) coastline using Al as a reference element

The metal concentrations in surface sediment of the South China Sea off the Terengganu coastline were determined. Cu, Cr and Zn concentrations were comparable to values for offshore regions of the South China Sea and of concentrations of coastal sediments from the more developed west coast of Malaysia. Direct comparisons with earth crust values for Cd and Pb ratios to Al indicate anthropogenic pollution by these metals. As the sediments of the area studied are composed of significant proportions of quartz and carbonate, from shells and coral, direct ratioing to Al would result in anomalous values. Thus enrichment factor (EF) values using Al as a reference element were determined and showed that sampling sites off the major rivers of Terengganu were anthropogenically influenced by Pb and Cd. Sources of pollution are probably sewage, agricultural wastes and atmospheric deposition of Pb from the use of leaded petrol.

Metal concentrations in surface sediments of Paraíba do Sul River (Brazil)

The Paraiba do Sul River is located in a strategic region between the most important urban and industrial centers of Brazil. In the last years, an increase in the water pollution has been reported, caused by the untreated domestic sewerage of the inhabitants, effluents discharged by various industries, mining activities and sand extraction from the riverbed. This work used total reflection X-ray fluorescence with synchrotron radiation (SRTXRF) to determine metals in the bioavailable and residual fractions from the surface sediments. The metals identified were Ti, Cr, Mn, Fe, Cu, Zn, Rb, Sr, Ba and Pb.

Distribution of Heavy Metal Concentrations in Surface Sediments in Dubai Creeks, United Arab Emirates

Dubai is developing rapidly and many developmental activities are concentrated around its Creek. The present study reports the lateral distribution of heavy metals and compares it with local historical record of heavy metal concentrations. For this purpose surface sediment samples were collected and analyzed for metal contents, total organic carbon content (TOC), mineralogy and grain size. The percentages of the different grain size fraction of the collected sediments were as follow 65% for sand size, 15% for silt size fraction, and the rest accounted for clay size fraction. The microscopic analyses indicate that the sediment composed mainly from carbonate and quartz with traces of rock fragments. Such mineral composition is not believed to be a potential source of heavy metal. The study found that the average recorded heavy metal concentrations in the collected sediment samples were 87, 96, 127, 38.5, and 279 ppm for Cr, Cu, Ni, Pb, and Zn, respectively. Those values were slightly higher than metal concentrations recoded in 2001 with 1.22 (Cr), 2.5 (Cu), 2.87 (Ni), 0.69 (Pb), and 2.1 (Zn) folds. However, in 2001 and 2003 the measured metal contents, along the creek, were lower than those of the average earth crust. Along the Creek most metals recorded the highest concentrations in the upper reach of the Creek. The distribution of the measured heavy metals was not affected significantly with the TOC values. The present study also documented obvious related point sources of pollution.

Distribution and enrichment evaluation of heavy metals in Mejillones Bay (23°S), Northern Chile: Geochemical and statistical approach

A suite of 36 surface sediment samples, taken between 10 and 100 m water depth in Mejillones Bay (Northern Chile), were analyzed for mineralogy, grain size, total organic carbon, Al, and heavy metal content (Cd, Zn, Ni, Mn, V, Mo). Quartz and feldspars were the main lithogenic minerals and carbonate the predominant biogenic mineral. Sediments were fine sands in the shallow zone and organic silt in the deeper zone. Enrichment Factor and Factor Analysis approach showed that the presence of Mn in the marine sediment of Mejillones is due to a partial influence of continental input, while all other metals are not supported by lithogenic debris. Although all metals showed high concentrations in the marine sediment of Mejillones Bay, comparison between metal concentration in surface sediments and preindustrial levels in this bay, show that present values agree with natural levels.

Study of Fractionation and Potential Mobility of Metal from the Guadalquivir Estuary: Changes in Mobility with Time and Influence of the Aznalcollar Mining Spill

This study analyzed the evolution of metal levels in surface sediments from the Guadalquivir estuary between 1997 and 2002 and assessed the impact of the April 1998 Aznalcollar tailings dam failure and subsequent cleanup on metal concentrations in surface sediments. We also analyzed metal distribution with time in five chemical fractions of the surface sediments: exchangable, carbonate, reducible, oxidizable, and residual. This work showed that the April 1998 Aznalcollar tailings dam failure caused a considerable increase in the concentrations of Cd, Zn, Cu, and Pb in the surface sediments of the Guadalquivir estuary. It was also found there was a change in the distribution of Cd, Zn, Cu, and Pb between the chemical fractions of the sediment after the failure of the dam. There were increases in the percentages of Cd in the carbonate fraction, of Zn and Pb in the reducible fraction, and of Cu in the oxidizable fraction, whereas the percentages of these elements associated with the residual fraction decreased. In 1999, there was a decrease in the metal concentrations in the surface sediments from the Guadalquivir estuary, and by 2000 the chemical distribution and metal levels had returned to levels similar those before the dam failure.

Heavy metals in Lake Balaton: water column, suspended matter, sediment and biota

During the period 1999–2002, five sampling cruises have been carried out on Lake Balaton to assess trace metal distribution in the lake and to identify major sources. Eighteen elements, including Cr, Co, Ni, Cu, Zn, Cd, Pb (trace metals) and Al, Ba, Ca, Fe, K, Mg, Mn, Na, P, S, Sr (major metals), were determined in one or more of the lake's compartments. Lower trace metal concentrations in rainwater were observed in June and February 2000, while much higher levels were present in September 2001 (during a storm event) and in snow (February 2000). In the Northern and Western parts of the lake, especially at the inflow of river Zala and the locations of the yacht harbours, metal concentrations were higher in almost all compartments. Because the lake is very shallow, storm conditions also change significantly the metal distributions in the dissolved and particulate phases. The Kis-Balaton protection system located on Zala river functions very efficiently for retaining suspended particulate matter (SPM; 72% retention) and associated metals. Metal concentrations in surface sediments of the lake showed a high variability. After normalisation for the fine sediment fraction, only a few stations including Zala mouth appeared to be enriched in trace metals. In zooplankton, Zn seemed to be much more elevated compared to the other trace metals. Based on the molar ratios of the trace metals in the various compartments and input flows of the lake, several trends could be deduced. For example, molar ratios of the trace metals in the dissolved and solid (suspended particulate matter and sediments) phases in the lake are fairly similar to those in Zala River.

Assessment of metals in sediments from Lake Macquarie, New South Wales, Australia, using normalisation models and sediment quality guidelines

Industrial activity since the 1890s and, more recently catchment development has resulted in significant metal contamination in Lake Macquarie, an estuary in New South Wales, Australia. This paper presents an analysis of metal concentrations in surface sediments from Lake Macquarie using normalisation models to estimate enrichment relative to natural background concentrations and by comparing concentrations with sediment quality guidelines (SQGs) and effects range median quotients to assess the potential for ecological harm. Of the 12 metals examined, cadmium, lead, mercury, selenium, silver and zinc were enriched in surface sediments throughout the lake. The greatest contamination was found in the north of the lake and, for selenium, also in areas adjacent to two power stations. Comparisons with SQGs and effects range median quotients found that sediments from a site in Cockle Bay had concentrations of metals with the highest likelihood of causing adverse effects on sediment associated biota, and that the likelihood adverse decreased with distance from Cockle Bay. Comparisons with historical sediment quality data indicated that there has been a marked reduction in surface metal concentrations throughout the lake over 15 years. Models could not be constructed for all metals due to low background concentrations. For most metals, simple linear regression models were adequate, but for selenium and arsenic a multiple regression model provided a better estimate of background concentrations. SQGs possibly overestimated effects for arsenic, which has naturally high concentrations in the lake and underestimated the potential for ecological effects in coarser sediments.

Distribution and partitioning of heavy metals in estuarine sediment cores and implications for the use of sediment quality standards

Abstract. Total metal concentrations in surface sediments and historically contaminated sediments were determined in sediment cores collected from three estuaries (Thames, Medway and Blackwater) in south-east England. The partitioning behaviour of metals in these sediments was also determined using a sequential extraction scheme. These data were then compared with sediment quality values (SQVs) to determine the potential ecotoxicological risk to sediment dwelling organisms. When total metal concentrations in surface sediments are examined, no risk to biota in any of the estuaries is indicated. However, when historically contaminated sediments at depth are also considered, risks to biota are apparent and are greatest for the Thames, followed by the Medway and then the Blackwater. This suggests that regulatory authorities should examine vertical metal profiles, particularly in estuaries that are experiencing low sediment accumulation rates where historically contaminated sediments are in the shallow sub-surface zone and where erosion or dredging activities may take place. When metal partitioning characteristics are also considered, the risk to biota is comparable for the Medway and the Blackwater with the potentially bioavailable fraction presenting no ecotoxicological risk. Conversely, over 70% of metals are labile in the Thames Estuary sediments and toxic effects are probable. This suggests that the application of SQVs using total sediment metal concentrations may over- or under-estimate the risk to biota in geochemically dissimilar estuarine sediments. Keywords: sediment quality values, estuarine sediments, metal contamination, partitioning, sequential extraction