Heavy Metals In Sediment Cores Research Articles

Contamination Assessment of Heavy Metals in Sediment Cores from De Montigny Lake around Siscoe-Sullivan Former Mining Sites, Val-d’Or, Canada

Seven sediment cores were collected from De Montigny Lake in order to determine concentrations, and contamination assessment of heavy metals such as Cr, Zn, Ni, Pb, Cu, Co and Cd. The mean concentrations of heavy metals are as follows: 48.3 mg/kg for Cr, 36.4 mg/kg for Zn, 20.6 mg/kg for Ni, 14.7 mg/kg for Pb, 10.2 mg/kg for Cu, 6.7 mg/kg for Co and 0.1 mg/kg for Cd. Based on the sediment quality guidelines, the mean concentration metals such as Cr, Cu and Ni exceeded the US Environmental Protection Agency (USEPA) guideline. However, the concentration of Cr was more than the Canadian Water Quality Guidelines for Protection of Aquatic Life (CCME), and Threshold Effect Level (TEL) guidelines. The metal contamination in the sediments was also evaluated using Enrichment Factor (EF) and geoaccumulation index (Igeo) to assess natural and anthropogenic factors. The results of enrichment factor methods demonstrated that sediments from De Montigny Lake were moderately to high enriched, mainly controlled by through anthropogenic activities. According to Sediment Quality Guidelines (SQGs), the concentrations metals from the core sediment of De Montigny Lake are classified as having moderate impacts with potential adverse biotoxic effects.

Distribution of Heavy Metals in Sediment Cores Collected from the Nakdong River, South Korea

Understanding the distribution of heavy metals in sediment is necessary because labile heavy metals can partition into the water column and bioaccumulate in aquatic organisms. Here we investigated six heavy metals (Co, Cu, Mn, Ni, Pb, and Zn) in sediment cores using a five-step sequential leaching method to examine the occurrence of heavy metals in the sediment. The results showed that all elements, except Mn, are depleted in the exchangeable and carbonate fractions. However, heavy metal concentrations are much higher in the Fe-Mn oxide and organic matter fractions, especially for Cu, indicating enrichment in the organic matter fraction. Furthermore, contamination parameters (contamination factor and geoaccumulation index) indicate that Mn contamination is high, primarily derived from anthropogenic sources, presenting a potential risk to ecosystems in the Nakdong River.

The spatial-temporal evolution of heavy metal accumulation in the offshore sediments along the Shandong Peninsula over the last 100 years: Anthropogenic and natural impacts

The anthropogenic and natural impacts on the temporal and spatial variations of heavy metals in sediments under the Shandong Peninsula coastal current are still unclear. Here, the concentrations\\burial fluxes of Cr, Cu, Zn, As, and Pb in three sediment cores retrieved from the Bohai Sea and the Yellow Sea along the Shandong Peninsula were analyzed to study the spatial-temporal variability of heavy metal accumulation over the last century. The results showed that the buried heavy metal fluxes were relatively low at the end of the Shandong Peninsula coastal current. The enrichment factor (EF) and geoaccumulation index (Igeo) indicated that those metals did not severely pollute the sediments except As that reached a moderate enrichment. Principal component analysis (PCA) revealed that Cr, Cu, Zn, and Pb were mainly derived from natural weathering and As was determined by anthropogenic contamination. The strength of the Shandong Peninsula coastal current, the Yellow River estuary location, and sediment discharge load significantly influenced the concentrations of natural-origin heavy metals by affecting sediment grain size and the source-sink process. The emission of pollutants from agricultural and industrial activities in the Shandong Peninsula region resulted in As enrichment since the 1950s. Moreover, the EF values of heavy metals in sediment cores from China's coastal seas showed apparent spatial variations of heavy metal pollution but had coherent temporal variability with China's economic development process. Heavy metals pollution has weakened in most coastal seas since the 2000s, likely due to the extensive industrial upgrading and the implementation of pollution control. These results have a reference significance for studying the evolution and source-sink process of the heavy metals in offshore sediments and tracing anthropogenic impacts in different periods.

Vertical distribution and contamination assessment of heavy metals in sediment cores of ship breaking area of Bangladesh.

Vertical heavy metal profiling reflects the history of the deposition of metals and helps to understand the characteristics of accumulation in various layers of the sediment. Nevertheless, no previous studies in Bangladesh had focused on the vertical distribution of heavy metals in core sediments. In this study, vertical distribution, contamination level and potential ecological risks of six heavy metals (Zn, Cu, Pb, Cr, Ni, Mn) from the core sediment of ship breaking were assessed and compared with the non-ship breaking area of Bangladesh. The concentration (µg/g) of heavy metals in the 0-10cm (surface), 10-20cm (middle) and 20-30cm (bottom) of sediment cores was as follows, respectively: Zn (35.54-100.68, 37.27-258.02, 42.78-66.45); Cu (16.38-75.25, 30.64-92.02, 34.99-52.98); Pb (4.84-132.08, BDL-204.48, BDL-23.51); Cr (14.57-42.13, 25.31-42.71, 15.26-36.34); Ni (4.02-42.23, 4.94-43.70, 4.40-43.13); Mn (198.74-764.16, 257.77-980.50, 255.62-856.44). The heavy metal content of core sediment from the shipbreaking region was substantially higher than that of non-shipbreaking area. Except for Ni, heavy metal content was highest in the middle layer, followed by the upper and lower layers of the sediment core. Contamination exponents such as enrichment factor, contamination factor and geo-accumulation index (Igeo) revealed contamination by Zn, Cu and Pb while potential ecological risk factor ([Formula: see text]) and risk index suggested low ecological risk by studied heavy metals except for Pb. Correlation matrix, cluster analysis and principal component analysis indicated that all studied heavy metals could have similar anthropogenic origins.

Vertical profiles and contamination assessments of heavy metals in sediment cores from typical intertidal zones in northern China

The concentrations of 7 heavy metals (Cu, Pb, Zn, Cr, Cd, As and Hg) were analysed in 12 sediment cores collected from 6 typical intertidal zones in northern China. The data reveal that the environmental quality of the northern Chinese intertidal environment has gradually improved and that the concentrations of Cu, Pb, Zn, Cr, Cd, As and Hg averaged over all sediments were 29.2, 25.8, 78.5, 72.2, 0.168, 10.7 and 0.044 mg/kg, respectively. The results of the geoaccumulation index and enrichment factor methods demonstrate that most of the sediments in the intertidal zone in northern China have good environmental quality, although some areas are contaminanted, including the Yangtze River Estuary, which is seriously contaminanted. According to sediment quality guidelines, the heavy metal concentrations in the sediments in the 6 typical intertidal zones in this survey are categorized as having moderate impacts with potential adverse biotoxic effects.

Speciation and migration of heavy metals in sediment cores of urban wetland: bioavailability and risks.

To examine the status and risk of heavy metal pollution in an urban wetland in China, the distribution and speciation of chromium (Cr) and other metals (Cd, Cu, Pb, and Zn) were examined. We investigated the impact of three major land uses (residential and industrial (RI), orange plantation (OP), and mixed OP and RI (OPRI)) on the heavy metal characteristics using sediment cores (0-60cm below water/sediment interface) collected in Sanyang Wetland, China. It was found that all the metals (Cr, Cd, Cu, Pb, and Zn) had lower concentrations in the top layers but higher contents in the bottom layers of sediments. Species of metals in sediments were dominated by their secondary phase (i.e., exchangeable and carbonate bound, Fe-Mn bound and organic bound) with relatively low contents of primary phase (i.e., residual form), except for Cr in RI affected river sediments that had a relatively high content of primary phase (20.97-36.07%). The ratio of secondary phase to primary phase (RSP) and risk assessment code (RAC) methods were applied to assess environmental risk. The results implied that the metal mobility and bioavailability could significantly cause urban wetland environmental quality decline, and thus enhanced strategies should be required to target the capture and removal of metals.

Contamination and environmental risk assessment of heavy metals in marine sediments from Tahaddart estuary (NW of Morocco)

The distribution, contamination status, and ecological risks of heavy metals in Tahaddart estuary were investigated. 24 surface sediment samples and two cores were collected and analyzed for major (Al and Fe), heavy metals (As, Cd, Cr, Cu, Ni, Pb, and Zn), and grain size composition. The heavy metals assessment was carried out using different environmental indices. The results indicated that the spatial distribution patterns of Al, Fe, and Zn were mainly determined by the distribution of the finer grained fraction (<63 μm) in the sediment. In contrast, As, Cd, Cr, Cu, Ni, and Pb concentrations were controlled by anthropogenic activities (vehicular traffic from Highway Bridge and thermal power plant). The distribution of heavy metals in sediment cores showed an upward enrichment in heavy metals with high concentration found in the uppermost may related to the increasing in human activities. The pollution indexes confirmed that the Tahaddart estuary sediment was considerably to high contaminated by heavy metals near to different anthropogenic inputs. Similarly, the potential ecological risk index and the biological risk index present 21% probability of toxicity posing potential risk to the aquatic organisms. These results provide basic information that can be used to protect and improve the quality of this ecosystem.

A method to assess the evolution and recovery of heavy metal pollution in estuarine sediments: Past history, present situation and future perspectives

A methodology to assess the historical evolution and recovery of heavy metal pollution in estuarine sediments was developed and is presented here. This approach quantifies the distribution of heavy metals in sediment cores, and investigates the influence of anthropogenic activities and/or core locations on the heavy metal pollution, by proposing and using sediment quality indices and polynomial regressions.The method has been applied to the Suances Estuary confirming its suitability as a comprehensive and practical management tool. In this estuary, the evolution of heavy metal pollution (since 1997–1998 to 2015) pointed out the deeper the sediments, the more polluted, indicating a recovery at the upper layers due to the closure and ending of washing discharges from mining, and the reduction of metal loads from industrial wastewaters. In terms of global pollution, the intertidal and subtidal sediments will require 43.1±2.8 and 8.6±0.6years to be unpolluted, respectively.

Vertical profile, contamination assessment, and source apportionment of heavy metals in sediment cores of Kaohsiung Harbor, Taiwan

Six sediment cores collected at the Kaohsiung Harbor of Taiwan were analyzed to evaluate their vertical profiles, enrichments, accumulations, and source apportionments of heavy metals. This was performed to investigate any potential ecological risks posed by heavy metals. Results indicated that the mean heavy metal content (mg kg−1) in the six sediment cores was as follows: Hg (0.4–6.4), Cd (<0.05–2.4), Cr (18–820), Cu (16–760), Pb (31–140), and Zn (76–1900). The patterns of heavy metal content in the sediment cores differed substantially among the four river mouths. However, the vertical profiles of metals were relatively stable, indicating that wastewater has the constant characteristics and has been discharged into the rivers for a long period of time. Results of pollution assessment of enrichment factor, geo-accumulation index, and pollution load index revealed that river mouths experience severe enrichment, strong accumulation, and high contamination from the primary heavy metals. It was not consistent in the assessment results of mean effect range median quotient, potential ecological risk index, and total toxic unit method. Potential ecological risks caused by Hg in the sediments at Canon River and Love River mouths on aquatic organisms were extremely high. The estimates derived from the receptor modeling of multiple linear regression of the absolute principal component scores indicated that the contributions of the composite heavy metals derived from the Canon River and the Love River on the potential toxicity and risks to the water environment of Kaohsiung Harbor were highest, followed by those derived from Salt River and Jen-Gen River.

Speciation and Bioavailability of Heavy Metals in Sediments Taken from Wetland in the Huaihe River Basin

AbstractThe fractions of heavy metals in sediment cores taken from the riverine wetland located in the Huaihe River Basin, China, were analyzed using BCR (European Communities Bureau of Reference) ...

Distribution of heavy metals in sediment cores of Lake Pamvotis (Greece): a pollution and potential risk assessment.

Concentrations and vertical distributions of metals in surface sediments of Lake Pamvotis (NW Greece) were assessed using energy-dispersive X-ray fluorescence spectrometry. A wide range of values was determined, associated with the specific types of contaminating effluents draining into different parts of the lake. Overall, Cr levels ranged from 43 to 3295mgkg(-1), Ni from 13 to 372mgkg(-1), Cu from 15 to 24,985mgkg(-1), Zn from 129 to 22,983mgkg(-1), Zr from 64 to 4063mgkg(-1) and Pb from 19 to 2634mgkg(-1). Principal component analysis revealed distinct elemental fingerprints in each sampling location, while correlation analysis and hierarchical agglomerative cluster analysis provided insight to metal association and pollution sources. Enrichment factors and geoaccumulation indices were calculated to quantify sediment contamination, and potential ecotoxic effects were evaluated based on sediment quality guidelines. Moderate to very severe enrichment in Zn, Cu and Pb was evidenced in sediments near the lake's outflow. The proximity of these sampling points to a heavy traffic national road suggests that roadway runoff is the dominant source of elevated metal levels. Contribution from municipal sewage water discharges from the nearby communities should also be accounted for. Moderate to very severe Zn and Pb enrichment was determined in the vicinity on the main lake's inflow, primarily associated with runoff and leaching from agricultural land. Very severe to extremely severe Cr enrichment was detected in the same location, most likely associated with wastewater discharged into the lake over several decades, by nearby-operating leather tanneries. The above two locations were ranked at the highest priority level in terms of potential ecological risk.

Concentrations and Bioavailability of Heavy Metals in Sediments of Riverine Wetlands Located in the Huaihe River Watershed, China

Fractionations and mobility of heavy metals in sediment cores taken from the Suoxu River located in the Huaihe River watershed, China, were carried out and assessed. The results revealed that the total concentrations of Cd, Cr, Cu, Pb, and Zn reached up to 0.38, 70.2, 92.1, 35.9, and 227.0 mg kg−1 in sediment cores from the upstream, 0.19, 66.5, 27.4, 29.1, and 80.1 mg kg−1 from the midstream and 0.18, 49.4, 24.2, 28.5, and 64.8 mg kg−1 from downstream of the river, respectively. The concentrations of heavy metals near the surface of sediment cores from the upstream were significantly higher compared to the bottom and the downstream of the river. Significant positive correlations between total organic carbon and metals suggested that heavy metals tended to be adsorbed by organic material, especially in sediment cores from the upstream of the river possessing high concentrations of organic matter. In addition, the geoaccumulation index (Igeo) values of deep sediment samples were lower than those of surficial sediment samples and increased drastically from about 4 cm depth layer. Igeo values greater than 1 in the upper layer of sediments from the upstream of the river revealed that the upper stream of the Suoxu River was exposed to moderate pollution. The increase of metal concentrations was connected with the inflow of the contaminated water from industrial effluents and domestic sewage. Finally, the sequential extraction after the European Communities Bureau of Reference procedure indicated that Cd was primarily bound to acid extractable fractions with a percentage from 47.4 to 63.8%, 51.1 to 73.3%, and 47.5 to 71.9% in the three sediment profiles, respectively. The upstream of the river was exposed to toxicity of Cd for the significant mobility. Cu and Pb possessed potential bioavailability because of the association with reducible and oxidizable species and could be released and entered into the food chain, whereas Cr and Zn displayed weak mobility because of the connection with residual fractions, concluded from the largest proportions accounting for total concentrations.

Assessment of heavy metals in sediment cores from Xiangjiang River, Chang-Zhu-Tan region, Hunan Province, China

Samples were collected from two core sediments (C1 and C2) of Xiangjiang River, Chang-Zhu-Tan region, Hunan Province, China. The heavy metal contents are relatively higher, especially for the surface or near the surface layers. The calculated anthropogenic factor values indicate that all the heavy metals except for Cr in the core samples are enriched, especially for Cd, with the maximum enriching coefficients of 119.44, and 84.67 in C1 and C2, respectively. The correlation of heavy metals with sulphur indicates that they are precipitated as metal sulphides. Correlation matrix shows significant association between heavy metals and mud. Factor analysis identifies that signified anthropogenic activities affect the region of Xiangjiang River.

Historical variation of heavy metals with respect to different chemical forms in recent sediments from Xianghai Wetlands, Northeast China

The major objective of this research is to determine whether pollution trends could be reconstructed from sediment records at the downstream wetlands of the Huolin River. Sediment cores, representing a range of watershed characteristics and anthropogenic impacts, were collected from two marshes at the Xianghai Wetlands in order to trace the historical variation of heavy metals, accumulation rates, and chemical forms. Cores were 210Pb-and 137Cs-dated, and these data were used to calculate sedimentation rates and sediment accumulation rates that were compared with environmental change. Ranges of dry mass accumulation rates and sedimentation rates were 0.27–0.96g/ cm2/yr and 0.27–0.90cm/yr. After normalization to Al, the anthropogenic enrichment of Cu, Zn, Cr, and Pb occurred in the uppep layer of sediments and indicated that heavy metal contamination coming from the hydrologic inputs primarily occurred after the 1980s. This result was consistent with two decades of surface coal-mining history within the upstream region of Huolin River. Sediment inputs of most heavy metals at Xianghai Wetlands began to increase over background levels at around 1885 and were generally consistent with the time of the Qing Dynasty’s immigration settlement. The anthropogenic inputs of Cu, Zn, Fe, Mn, Cr, and Pb have been 1.20–3.67 times greater than values of their natural inputs after the 1980s, which may be a result of increased input of heavy metal-rich alluvial deposits derived from surface coal-mining activities in the watershed. Sequential extraction was used to describe partitioning of heavy metals among different mineralogical components in sediments, and results showed that heavy metals in sediment cores were mostly associated with the lithogenic bonding forms (residual fraction) and least with the exchangeable fraction (except Pb). The major fraction of Pb was in the Fe−Mn oxide fraction (mean: 40.7–48.6%), indicating that Pb in these sediments had greater mobility and suggested that it might be primarily from anthropogenic sources.

Heavy metals in sediment cores from a tropical estuary affected by anthropogenic discharges: Coatzacoalcos estuary, Mexico

Large scale industrial development has taken place in the Coatzacoalcos river estuary, SE Mexico, over the last 32 years, and the area is now regarded as the most polluted coastal area of Mexico. A series of sediment cores were taken from the lower Coatzacoalcos river and the estuary, and the concentrations of trace elements (Zn, Co, Cu, Cr, Ni, Pb, V), major elements (Al, Si, Mn, Fe, Ti, Ca, Mg, Na, K, P) and organic matter determined. Heavy metal concentration seems to be largely dependant on proximity to industrial areas, with highest metal concentrations (particularly for Zn, Ni and Cu) found at Teapa, the most heavily industrialized site, and lowest values found at Jicaro, upstream of the main industrial areas. At all of the sites examined, heavy metals either show a relatively uniform distribution with depth, or subsurface maxima, which reflect changes in sediment composition. There is little evidence for significant early-diagenetic remobilization at any of the sites studied. 210Pb and 137Cs data at Teapa indicate that the sediments have accreted rapidly and may be vigorously mixed, and so these sediment cores cannot be used to reliably reconstruct temporal changes in pollutant input.

Fractionation of heavy metals in sediment cores from the Ell-Ren River, Taiwan

Fractionation of heavy metals (Cr, Cu, Co, Zn, Ni, and Pb) in sediment cores taken from three heavily polluted locations of the Ell-Ren River in southern Taiwan was studied. After the three sediment cores were separated into several depth sections, sequential extraction procedure was used to determine the variations in heavy metal binding fractions (exchangeable, bound to carbonates, bound to Mn oxides, bound to Fe oxides, and bound to organic matter) with different sediment depth, and followed by multivariate analyses. It turns out that a deeper sediment depth tended to result in smaller amounts of total extractable heavy metals (TEHMs), indicating that heavy metal pollution of the river has been intensifying these years. The decreasing order of TEHMs was: Zn &amp;gt; Cu &amp;gt; Pb &amp;gt; Cr &amp;gt; Ni &amp;gt; Co. The TEHMs Zn and Cu detected from different depth of the three sediment cores were mainly originated from “bound to carbonates” and “bound to organic matter” fractions, respectively. Also, the percentages of the heavy metals contained in each of the five binding fractons only slightly varied with sediment depth. From multivariate analyses, all the heavy metals except Co behaved similarly and might be discharged from the same pollution sources.

Fractionation of heavy metals in sediment cores from the Ell-Ren River, Taiwan

Fractionation of heavy metals (Cr, Cu, Co, Zn, Ni, and Pb) in sediment cores taken from three heavily polluted locations of the Ell-Ren River in southern Taiwan was studied. After the three sediment cores were separated into several depth sections, sequential extraction procedure was used to determine the variations in heavy metal binding fractions (exchangeable, bound to carbonates, bound to Mn oxides, bound to Fe oxides, and bound to organic matter) with different sediment depth, and followed by multivariate analyses. It turns out that a deeper sediment depth tended to result in smaller amounts of total extractable heavy metals (TEHMs), indicating that heavy metal pollution of the river has been intensifying these years. The decreasing order of TEHMs was: Zn > Cu > Pb > Cr > Ni > Co. The TEHMs Zn and Cu detected from different depth of the three sediment cores were mainly originated from “bound to carbonates” and “bound to organic matter” fractions, respectively. Also, the percentages of the heavy metals contained in each of the five binding fractons only slightly varied with sediment depth. From multivariate analyses, all the heavy metals except Co behaved similarly and might be discharged from the same pollution sources.

Heavy metals in sediment cores from a NW Spain estuary.

Core samples have been used to describe the chronology of heavy metal inputs to aquatic systems. Metal concentration profiles have been investigated to detect pollution, to establish when the polluting event started, and to quantify its magnitude relative to [open quotes]precivilization[close quotes] background values. Less frequently, and mainly in studies of coastal systems, the heavy metal nonresidual fraction has been measured to estimate the portion of trace metals potentially available for the biota or remobilization processes, and to assist in identifying the origin of metal inputs. This work is part of a wider study of metal concentrations in organisms and superficial sediments from a small estuary in NW Spain. The aims of this research were to detect any potential pollutant input to the sediments of the estuary, and to establish the influence of postdepositional redistribution on the heavy metal concentrations of oxidized surface sediments. 17 refs., 1 fig.

Spatial and temporal variation of heavy metals in sediment cores from the calcasieu river/lake complex

Sediment cores were obtained from several locations in the Calcasieu River/Lake Complex (Lousiana), including Calcasieu Lake, Calcasieu River, two bayou tributaries, and Lake Charles, during the period from November 1983 to November 1985. The cores were analyzed for Cu, Zn, Cr, and Pb. The approximate sedimentation rate and a core chronology were determined by the use of 137Cs and 210Pb. The increase in metal concentrations after 1933, particularly along Bayou d'Inde where most industries are located, points to anthropogenic input of these metals to the system. The fact that metal concentrations tend to merge to a common value prior to 1940 throughout the system suggests that geological factors do not contribute to the observed variations in metal concentrations of heavy metals found in this area. The background concentrations of heavy metals found in this study for the Calcasieu River/Lake Complex were: Cu (10 mg kg−1), Cr (25 mg kg−1), Pb (8 mg kg−1), and Zn (40 mg kg−1), The main emphasis of the study focused along Bayou d'Inde due to the enhanced levels of heavy metals found.

Concentration of heavy metals in sediment cores from selected Wisconsin lakes

Concentration of heavy metals in sediment cores from selected Wisconsin lakes