Heavy metals distribution and fractionation in sediments of the Mahanadi River basin, India

Heavy metals distribution in core sediments, different size fractions of bed sediments (>212 urn, 90-212 jam, 63–90 urn, 53–63 urn, < 53 urn), and suspended sediments (>30 urn, 20–30 m, 10–20 urn, 2–10 urn, <2 m) have been discussed. Pb, Zn, and Cr have been accumulating in recent years in the sediments. Si, Al, Fe, Ca, and Mg dominate the bed and suspended sediment composition. Metals show increasing concentrations in finer sediments. Applying multivariate analysis to sediment composition, metals have been grouped into different factors depending upon their source of origin. Chemical fractionation studies on suspended and bed sediments show Fe, Zn, Cu, and Pb are associated with the residual fraction and Mn with the exchangeable fraction.     

Heavy metals in sediments of the Tecate River, Mexico

Ten sites along the Tecate River, Mexico were sampled to evaluate the cadmium, lead, nickel and chromium concentrations in sediments. The result shows contamination for cadmium in most of the sites, where two sites were class 4 (polluted to strongly polluted) according to geoaccumulation index proposed by Muller. Two sites were found polluted for all the heavy metals analyzed (Cr, Cd, Pb and Ni), indicating the effect of anthropogenic activities. A correlation between Ni and Cd concentration had been found indicating a common source. These metals are usually used in electroplating industry. The results of this study can be used for decision makers to prioritize measures to control the pollution for these metals.     

Heavy metals distribution in Jamaica Bay sediments

Ninety-two sediment samples collected at 53 stations in Jamaica Bay from November 1970 to October 1973 were analyzed for Pb, Cr, V, Cu, Cd, Zn, Ni, Co, and percent organic carbon (ORC). Selected samples were analyzed for Hg. The concentrations of all metals correlate with each other and with organic carbon. Vanadium, cobalt, and nickel stand out as a separate component and are enriched relative to other metals in areas affected by petroliferous pollution. The metal concentrations are strongly influenced by the strength of tidal currents and proximity to pollution sources. Amount of rainfall and/or season affects metal concentrations in Grassy Bay (a deep restricted body of water within Jamaica Bay).     

Heavy metals in Oka river sediments (Urdaibai National Biosphere Reserve, northern Spain): lithogenic and anthropogenic effects

 The Oka River basin is located in the Urdaibai National Biosphere Reserve, North Spain. In order to obtain a preliminary view of its environmental conditions, nitric acid extractable Fe, Mn, Zn, Pb, Cu, Cr, Ni and Co, organic matter content (L.O.I.), geochemical fractionation of heavy metals and mineralogical composition were analysed in surficial sediments (fraction <63 μm) collected in October 1991. Relatively high concentrations of metals occurred in a sampling site upstream, due to a local natural enrichment controlled by weathering of volcanic rocks. Geochemical fractionation confirmed the lithogenic origin of metals, which were mainly associated to the detrital phase. The significant increase of heavy metals found in some samples collected in the municipal area of Gernika suggested a pollution effect, related to anthropogenic wastes. Large amounts of metallic slags have been found mixed with the sediments upstream from this locality. Nevertheless, in view of their composition, it is unlikely that these slags constitute a significant source of heavy metals in the studied area. In a second sampling in October 1997 an apparent decreasing trend in some heavy metal levels was noted, particularly for Pb and Cu. Nowadays, enrichment factors relative to background values confirm moderate anthropogenic influence on Zn, Pb, Cu, Cr and Ni concentrations. However, heavy metal levels in the Oka river sediments are much lower than those detected in other major rivers of the Basque Country (Nervión, Urumea, Deba). Received: 7 July 1997 · Accepted: 4 July 1998     

Heavy metals in sediments from San Antonio Bay and the northwest Gulf of Mexico

Sediments from San Antonio Bay, the northwest Gulf of Mexico, and the Mississippi River Delta were acid leached and analyzed for Fe, Mn, Pb, Zn, Cd, Cu and Ni by atomic absorption spectrophotometry. In order to account for differences in sediment clay, carbonate, and organic matter content, metal concentrations were normalized to Fe. Significant linear correlations of metals to Fe were obtained for unpolluted sediments and deviations from these “natural” statistical populations were found for areas thought to have metal input caused by man. San Antonio Bay sediments show little evidence of metal pollution despite 70 years of shell dredging in the bay. However, the San Antonio-Guadalupe River system, the bay's prime sediment source, has 10% to 50% higher than natural levels of Pb, Cd and Cu. Sediments from a 1500 km² area of the Mississippi River Delta have Pb and Cd concentrations 10% to 100% higher than expected levels. The vertical distribution of Pb and Cd in these sediments suggests that inputs have occurred during the past 30 to 40 years. We find no indication of metal pollution in other areas of the Delta or along the continental shelf of the northwest Gulf of Mexico.     

Heavy metal distribution in sediments of Krishna River basin,India

Suspended and bed sediments collected from the entire region of the Krishna River and its major tributaries were analyzed for heavy metals (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pb) by the thin-film energy dispersive x-ray fluorescence technique. There is considerable variation in the concentration of elements towards downstream, which may be due to the variation in the subbasin geology and various degrees of human impact. Suspended particles are enriched in heavy metals throughout the basin relative to bed sediments. The heavy metals are enriched in coarse size fractions (10–90 µm) throughout the Krishna River except its tributary Bhima, where finer fractions (2 µm) dominate. Transition elements correlate very well with each other. There is a striking similarity between the bed sediments of Krishna River and the Indian average. When the annual heavy metal flux carried by the Krishna River was estimated, and viewed in relation to the other major riverine transport, the Krishna is seen to be a minor contributor of heavy metals to the Bay of Bengal.     

Heavy metals in sediments from different environments of a northern Adriatic Sea area,Italy

Sediments from different environments of an area directly affected by the discharge of the Po River and 13 other minor rivers have been studied. Three main sources of metals and several distribution mechanisms can be identified. Concentration profiles of metals in a core allow one to establish background levels of finegrained sediments for Cd, Hg, Pb, and Zn Seabed sediments do not appear to be very polluted, mainly because of desorption and dilution processes     

Heavy metals distribution in the sediments of ganges and Brahmaputra rivers

Bed sediments were collected from the entire region of the Ganges basin and some parts of the Brahmaputra. In addition, selected stations were sampled for suspended sediments as well. The samples were analysed for a number of heavy metals (Fe, Mn, Ni, Cr, Cu, and Zn) by the thin-film energy dispersive X-ray fluorescence technique. There are pronounced temporal and spatial variations in the heavy metals distributions. Suspended sediments are 5–10 times richer than the bed sediments. None of the tributaries contribute significant heavy metal load, but around urban areas in Yamuna (tributary of Ganges), very high levels due to the distribution from the drainage network are observed. Compared to the Brahmaputra, the distribution and fractionation of heavy metals in the Ganges sediments are more erratic and highly variable. All the metals considered show high correlation among themselves. Given the high flux of suspended sediments from the Himalayan rivers (nearly 20% of the global flux), the worldwide budget for heavy metal transport may need to be suitably revised.     

Heavy metals and polychlorinated biphenyls in sediments of the Yangtze river estuary,China

Typical pollutants in sediments from 22 sampling sites of the Yangtze river estuary in 2006 were investigated in the present study. Arsenic, mercury, cadmium, copper, chromium, zinc, lead, and polychlorinated biphenyls of the Yangtze river estuary sediments were found as 6.49–17.6, 0.0164–0.0987, 0.059–0.319, 11.7–46.6, 10.5–113, 44.5–125, 14.8–32.7, and 0.0006–0.0026 mg/kg, respectively. Results indicated the presence of a contamination in the Yangtze river estuary. Through analyzing the contents of typical pollutants in sediments with adopting the index number techniques of Muller geoaccumulation index and Hakanson ecological risk factors and index, the quality status of these sediments were evaluated. Furthermore, the potential ecological risks of the estuary were determined quantitatively. The overall environmental quality of typical pollutants was generally in a good condition in most sites. The results showed that arsenic was the main environmental pollution factor, and cadmium was the main potential ecological factor. The highest potential ecological risk index appeared in the south branch of the Yangtze river, which was mainly due to terrestrial pollution in Shanghai. The results of this study can be used for decision makers to prioritize measures to control the pollution for these typical pollutants.     

Heavy metal and arsenic distributions in sediments of the Elba-Argentario basin, southern Tuscany, Italy

 Arsenic, chromium, cobalt, copper, lead, nickel, vanadium and zinc distributions in surficial and core sediments of the Elba-Argentario marine basin (southern Tuscany, central-western Italy) are reported. Analysis of such distributions compared with grain size and mineralogical data allowed the identification of areas showing trace element enrichments with respect to natural background. These enrichments are moderate and essentially restricted to Pb and Zn; only As shows a widespread, though not high, positive anomaly. This general pattern is in good agreement with the minor industrialization affecting the basin's watershed. An unexpected anomaly, concerning Co, Pb, and As, as well as Fe and Ti, has been pointed out close to Montecristo Island. This has been ascribed to illegal local dumping of chemical waste. Received: 12 January 1996 / Accepted: 9 September 1996     

Heavy metals in stream sediments: Error versus concentration

A regional geochemical mapping program in southern Norway carried out by the Geological Survey of Norway is based on sampling of stream sediments at road/stream intersections. At each site two individual subsamples have been taken. The subsamples were treated independently during the chemical analysis. This procedure enables an estimation of the reproducibility of the element concentration at each sample site. The paper gives results for the average relative total, sampling and laboratory errors at various levels of metal concentration using data for HNO₃ -soluble Mn, Pb and Cu as examples. For Mn and Pb the relative total error reaches a minimum near the median concentration and increases toward both the high and low concentrations. For Cu the relative total and laboratory errors decrease with increasing concentration throughout the whole concentration range, while the sampling error is fairly constant. The results suggest that the models which are commonly used for error determination in geochemical data, are too simple as far as relationships between error and concentration are concerned.     

Heavy metals in nearshore sediments of Kalpakkam,southeast coast of India

Kalpakkam, a tiny fishing hamlet dotting the east coast, halfway between Chennai and Pondicherry has become prominent due to the Madras Atomic Power Station. The present study aims at assessing the spatial and temporal distribution pattern of heavy metals (Cd, Pb, Zn, Cu, Ni, Cr, and Fe) from 12 stations along the inner shelf of Bay of Bengal, India, during pre-monsoon (PRM), monsoon, and post-monsoon (POM) seasons. The order of occurrence of the metals in sediments of Kalpakkam is Cr > Zn > Ni > Cu > Pb > Cd (excluding Fe since unit is in %) and exhibits a unique seasonal pattern with the highest values (average) during POM except for Cd which shows highest (average) concentration during PRM. In order to determine the sample association according to their geochemical composition and their granulometric characteristics, a correlation matrix was generated and sediment pollution indices viz., sediment enrichment factor and geoaccumulation index were computed. The results confirm anthropogenic input of Cd to nearshore sediments of Kalpakkam. Sources of Cd can be attributed to dredging activities at Edaiyur, direct dumping and sewage sludge from anthropogenic activities, which reach the study area through the Buckingham Canal opening at the backwaters—Sadras and Edaiyur, and extreme use of antifouling paints by fishing trawlers.     

Heavy metals in mangrove sediments of the central Arabian Gulf shoreline,Saudi Arabia

To assess heavy metals in mangrove swamps of Sehat and Tarut coastal areas along the Arabian Gulf, 18 sediment samples were collected for Al, V, Cr, Mn, Cu, Zn, Cd, Pb, Hg, Sr, As, Fe, Co, and Ni analysis. The results indicated that the distribution of some metals was largely controlled by anthropogenic inputs, while others were of terrigenous origin and most strongly associated with distribution of aluminum and total organic carbon in sediments. Mangrove sediments were extremely severe enriched with Sr (EF?=?67.59) and very severe enriched with V, Hg, Cd, Cu, As (EF?=?44.28, 37.45, 35.77, 25.97, and 11.53, respectively). Average values of Sr, V, Hg, Cd, Cu, Ni, As, and Cr were mostly higher than the ones recorded from the Mediterranean Sea, the Red Sea, the Gulf of Aqaba, the Caspian Sea, the Arabian and Oman gulfs, coast of Tanzania, sediment quality guidelines, and the background shale and the earth crust. Landfilling due to coastal infrastructure development around mangrove forests, oil spills and petrochemical and desalination effluents from Al-Jubail industrial city to the north were the anthropogenic activities that further enhanced heavy metals in the studied mangrove sediments.     

Heavy metals pollution on the sediments in lakes Dianchi, Erhai and Poyanghu and historical records

In this paper²¹⁰ Pb and ¹³⁷Cs dating methods were used to determine sedimentation rates of lakes Dianchi, Erhai and Poyanghu, and to establish the time scale of the sediments. Also based on geochemical records in the sediment column, the historical variation in heavy metal content over the past one hundred years was determined. Some element concentration increased rapidly after the 1970s, such as Cu, Zn and Mn in the sediments of northern Lake Dianchi, Cd and Mn in southern Lake Erhai and in the west central parts of Lake Poyanghu, Our investigations indicate that the increase in element concentration is caused by human activities. In order to understand the extent of the effect caused by human activities, we have calculated the flux of Zn, Cd and Mn. Results show that the flux caused by human activities is seven times greater than the natural one and the ratio is about 2 times in Lake Erhai and Lake Poyanghu.     

Using dual-isotope data to trace the origin and processes of dissolved sulphate: a case study in Calders stream (Llobregat basin,Spain)

Whereas most of the reported δ³⁴S values of dissolved sulphate are positive in the Llobregat basin, Calders stream, which is a tributary of the Llobregat River, is characterised by negative values. Stream waters, sampled monthly between 1997 and 1998, and quarterly in 1999, show an overall increase in δ³⁴S from −10‰ to 0‰, coupled with an increase in Na and Cl concentration. On the other hand, the oxygen isotopic composition of dissolved sulphate, δ¹⁸O, displayed an opposite trend with a slight decrease, from +9‰ to +6‰. Detailed sampling up stream in November 2000 indicated that, contrary to most of the surficial waters of the Llobregat basin with a δ³⁴S_SO4 mainly controlled by evaporites, in Calders stream, sulphate is derived from pyrite oxidation. The dual-isotope approach, coupled with chemical data, allowed us to identify the contribution of ³⁴S-rich sulphate effluents from anthropogenic sources, while mixing models, calculated between natural and anthropogenic sources, enabled us to estimate their contribution. Sudden increases of δ³⁴S and δ¹⁸O of dissolved sulphate in stream waters are believed to be caused by a sulphate reduction process related to oil spillage. The long-term enrichment in δ³⁴S, coupled with a decrease in δ¹⁸O_SO4, from Jan-97 to Aug-99, is interpreted as a progressive increase in the contribution of pig manure.     

Heavy metals in stream sediments: Effects of human activities

The content of 11 heavy metals in the sediments of a stream system was determined by atomic absorption analysis. Geochemical phases were investigated using a sequential extraction scheme, and bulk contents were assessed with a single HNO₃ extraction. Certain heavy metals were associated with different geochemical phases. Co, Mn, and Ba concentrated primarily in the carbonate and Mn phases, while all the remaining metals concentrated in the Fe and remnant phases. Features located along the stream system influenced the content of heavy metals. Results from the geochemical phases indicated Cu, Pb, Zn, Cd and Ag were emitted by one landfill, while Cd, Ba, and Ag were emitted by a second landfill. A wastewater treatment facility appeared to emit Ni and Cu. A stream draining a reservoir and joining the study stream resulted in dilution of the heavy metals in the sediments. A populated area along the study stream appeared to emit Mn. The single HNO₃ extraction procedure is quicker to perform than the sequential extraction but does not indicate the phase associations.     

Heavy metals in sediments as evidence for recent pollution and quasi-estuarine processes: an example from Lake Druzno,Poland

This article presents the results of a geochemical investigation of sediments from Lake Druzno (northern Poland), a reservoir fed by freshwater from the catchment, with periodic input of brackish water from Vistula Lagoon. This study analyzed the spatial variation in heavy metal content in surface sediments as well as the temporal changes in metal content in two sediment cores dated using the ²¹⁰Pb method. In the surface sediments, the highest metal concentrations were recorded in the northern part of the lake, with lower concentrations in the central and southern parts. Absolute values of metal concentrations in the cores were low, but normalization with respect to Al showed an increase during the second half of the 20th century. Mean enrichment factors (EF) in sediments from the second half of the 20th century ranged from insignificant (1–1.2) for Fe to (1.55–3.3) for Cu, Cd, Pb and Zn. The sediments deposited before 1950 had lower EF values (>1.5) and had low variability. Results from both the surface sediments and the cores indicate that the main source of lake pollution is brackish water intrusion from the Vistula Lagoon via the contaminated River Elbląg.