Heavy metal binding fractions in the sediments of the Godavari estuary,East Coast of India

Sequential chemical extraction was used to study the operationally determined chemical forms of five heavy metals (Pb, Cu, Zn, Co and Ni) and their spatial distribution in the sediments. The binding behaviour of heavy metals associating with Fe–Mn oxides showed a good correlation towards Cu, Zn and Co, but moderate linear dependence with Ni and Pb. Among the five metals, correlation between Fe–Mn oxide bound Cu and Fe–Mn oxides (r = 0.95) is highest. The coefficient of determination (r ²) in organically bound heavy metals versus organic matter (OM) ranges from 0.772 to 0.952, which indicates a good linear dependence. The OM fraction in the sediments is more accessible to heavy metals and is the major ligand available for complexation. In particular, Zn and Cu are preferentially bound to OM. In general, Zn co-precipitation with carbonates is the dominant chemical form when Fe–Mn oxide and OM are less abundant. In this study, however, carbonates were less abundant, hence Zn bound to carbonates was less pronounced. Based on the results, even if the excessive binding sites are contained in the sediments, competition of various complexation reactions between sediment phases and heavy metals could dominate metal association.     

Heavy Metals Fractionation in Ganga River Sediments, India

The Ganga River is the largest river in India which, originates in the Himalayas and along with the Brahmaputra River, another Himalayan river, transports enormous amounts of sediments from the Indian sub-continent to the Bay of Bengal. Because of the important role of river sediments in the biogeochemical cycling of elements, the Ganga river sediments, collected from its origin to the down stretches, were studied in the present context, to assess the heavy metals associated with different chemical fractions of sediments. The fractionation of metals were studied in the sediments using SM&T protocol for the extraction of heavy metals and geo-accumulation index (GAI) (Muller, Schwermetalle in den sedimenten des rheins – Veranderungen seit. Umschau, 79, 778–783, 1979) and Metal Enrichment Factor (MEF) in different fractions were calculated. As with many river systems, residual fractions constitute more than 60% of total metals, except Zn, Cu and Cr. However, the reducible and organic and sulfide components also act as major sinks for metals in the down stretches of the river, which is supported by the high GAI and MEF values. The GAI values range between 4 and 5 and MEF exceed more than 20 for almost all the locations in the downstream locations indicating to the addition of metals through urban and industrial effluents, as compared to the low metals concentrations with less GAI and MEF in the pristine river sediments from the rivers in Himalayas.     

Fractionation of eleven elements by chemical bonding from airborne particulate matter collected in an industrial city in Argentina

A four-step chemical sequential extraction procedure was used to evaluate the distribution of Al, As, Cr, Cu, Fe, Mn, Ni, Pb, Ti, V and Zn in airborne particulate matter collected on glass fibre filters using a high-volume sampler. Two sets of samples were collected in 2001 (winter and summer campaigns) in representative zones of an industrial city of Argentina. The leaching scheme was applied to PM-10 particles and consisted in extracting the elements in four fractions, namely soluble and exchangeable elements; carbonates, oxides and reducible elements; bound to organic matter and sulfidic metals; and residual elements. Metals and metalloids at microg g(-1) level were determined in each fraction by inductively coupled plasma optical emission spectrometry (ICP OES). Analyte concentration varied from 14 microg g(-1) (equivalent to 1.0 ng m(-3)) for As to 11.8 mg g(-1) (equivalent to 2,089 ng m(-3)) for Al. Seven elements, namely Al, Cr, Fe, Mn, Pb, Ti and Zn showed similar distributions in both seasons while As was distributed in a significantly different manner in each season. The results exhibited low As contents in the first and second fractions that could be associated with routine coal combustion and a high content in the third and fourth fractions of the summer samples that could be linked to the use of pesticides. Aluminium, As, Cu, Mn, Ni, Ti, V and Zn were found in different percentages in the more bioavailable aqueous fraction with As, Mn, V and Zn exhibiting solubilities greater than 1% while Cr and Pb being insoluble. The content of Al, Cr, Cu, Fe, Ni, Pb, and Zn in the residual fraction was, in average, higher than 50%. A comparative assessment of the use of the underlying information available from fractionation studies compared to that obtained from total element content was done for Fe and Mn. It showed that the results obtained using chemical sequential extraction procedures allowed further discrimination of the potential air pollution sources.     

Interseasonal distribution and partitioning of heavy metals in subtidal sediment of Qua Iboe Estuary and associated Creeks, Niger Delta (Nigeria)

An analysis of the distribution and chemical forms of selected metals: cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and lead (Pb) in subtidal sediments of Qua Iboe Estuary and adjourning creeks, collected between June 2000 and January 2001, were studied using a sequential chemical extraction method. The concentration of metals in each extracted fraction was determined using inductively coupled plasma spectrometer (ICP-AES). Pb, Cd and Cu appear to be the most abundant metal in the sediments of the systems, and are predominantly associated with the residual, organic and oxidisable phases. Results indicate that there are also insignificant components that are bound to both the exchangeable and carbonates fractions. Ni is largely associated with bioavailable phases with insignificant bound to organic matter and residual fractions. In general, an insignificant component of Cd and Pb are bound to organic matter phase. Moreover, speciation results indicate that metal contamination in the ecosystems investigated primarily comes from human-mediated sources. Thus, based on index of geoaccumulation calculated, sediments of these ecosystems have been classified as uncontaminated by Cr, Cu and Ni, strongly contaminated by Pb and extremely contaminated by Cd.     

Speciation of selected heavy metals geochemistry in surface sediments from Tirumalairajan river estuary, east coast of India

Surface sediment samples from the Tirumalairajan river estuary were studied for grain size pattern, organic matter, and heavy metals (Fe, Mn, Zn, and Pb) using the sequential and bulk metal extraction methods to evaluate metal behavior. Ten surface sediment samples were collected during the monsoon and summer seasons of the year 2009. The observed orders of concentrations of heavy metals in the sediments were as follows: Fe?>?Mn?>?Zn?>?Pb. The results obtained from sequential extraction showed that, among the metals studied, a larger portion of the metals were associated with the residual phase, although they are available in other fractions. The low concentration of metals available in bioavailable phases indicated that the sediments of Tirumalairajan river estuary were relatively unpolluted. Correlation analysis was also carried out to understand the associations of metals in different phases with sand, silt, clay, and organic matter. To understand the risk of heavy metals to sediment-dwelling organisms, the data were compared with risk assessment code and sediment quality values using the screening quick reference table. The main source of metals to the estuary is from the irrigation field and its associated activities in the study area.     

Nature of distribution of mercury in the sediments of the river Yamuna (tributary of the Ganges), India

Suspended Particulate Matter (SPM), surface (bed sediments) and short length cores of sediments collected from the largest tributary of the river Ganges, namely the river Yamuna, were analysed for total mercury as well as its fractionation in various size and chemical sites in the sediments following standard procedures. Also, attempts were made to determine the vertical distribution in sediments in relation to the recent timescale of a few decades. Our observations indicate that the SPM in general showed higher levels of total mercury compared to the surface sediments while at places the enhancement could be by a factor of 10, say around 25 microg g(-1) in the downstream region that integrates the industrial midstream and agricultural downstream terrain near its confluence with the Ganges. Surface sediments in the upstream direction near the Himalayan foothills and SPM in the lower reaches showed significant high Index of Geoaccumulation (Igeo) as defined by Müller. Size fractionation studies indicate that the finer fraction preferentially showed higher levels of mercury while in the lower reaches of the river, the total mercury is equitably distributed among all size fractions. The proportion of the residual fraction of mercury in relation to mobile fractions, in general decreases downstream towards its confluence with the Ganges river. In sediment cores, the vertical distribution show systematic peaks of mercury indicating that addition of this toxic metal to the aquatic system is in direct proportion to the increase in various types of human activities such as thermal power plants, land use changes (urbanisation) in the midstream region and intensive fertiliser application in lower reaches of this vast river basin.     

Determination and speciation of heavy metals in sediments of the Juru River,Penang, Malaysia

The Juru River flows through largely urbanized areas and is grossly polluted by domestic wastes and discharges from pig farms. Other than carrying highly polluting organic materials, these wastes are also contaminated with heavy metals. To ascertain the extent of heavy metal pollution in the river, total and non-residual concentrations of Cu, Pb, Zn, Mn and Fe in sediment samples collected along the river were determined. The results indicate that both the total and non-residual metal concentrations in sediments can successfully be used to identify heavy metal pollution sources. The speciation of Zn, Mn and Fe in the sediment samples were investigated using a sequential leaching technique which identifies the elements among six operationally defined host fractions: (1) exchangeable, (2) carbonate and surface-associated, (3) easily reducible, (4) moderately reducible, (5) bound to organic matter and sulphides and (6) residual. The results indicate that Zn is mainly associated with the reducible fractions. Zn and Fe found in the moderately reducible fraction are significantly correlated, indicating that iron oxides is the preferred host phase by Zn.     

Trace metal fractionation in the Pichavaram mangrove–estuarine sediments in southeast India after the tsunami of 2004

The geochemistry of coastal sediments of southern India was altered after the tsunami in 2004. A five-step sequential extraction procedure was applied to assess the effects of tsunami on mobility and redistribution of selected elements (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn). Ten surface sediments and three cores were analyzed for different metal fractions (exchangeable, carbonate, reduced, oxidized, and residual). Total metal concentrations increased in mangrove sediments after the tsunami, but their spatial distribution did not show significant variation (except Mn). The sediments were mixed by the tsunami, and there was lack of variation in metal concentrations in different fractions with depth (except Pb and Mn). High concentrations of Pb and Zn occurred in the oxide fractions, whereas Cu, Cr, Cd, and Ni were high in the organic and sulfide-rich fractions. Metals in the residual fraction (lattice bound) had the highest concentration suggesting their non-availability and limited biological uptake in the system. Most of the metals (except Mn) do not constitute a risk based on the different geochemical indices.     

Distribution and speciation of selected metals in surface sediments, from the tropical Zuari estuary, central west coast of India

Estuarine sediments are major reservoirs for the metals. Distribution and mobility of metals within estuaries depends strongly on their specific chemical form. In the present study, surface sediments from Zuari estuary, Goa were analysed by a sequential procedure for Fe, Mn, Cu, Zn, Cr and Co to determine their distribution in five geochemical phases (Exchangeable, carbonate, Fe-Mn oxide (reducible) organic bound (oxidisable) and residual). The total metal content, sand, silt, clay and organic carbon were also determined of the surface sediments. The total metal contents were found to be greater than the background concentrations of average shale values as well as to that of earlier studies indicating enrichment probably due to the anthropogenic origin of metals. The results obtained from sequential procedure showed that among the studied elements, Mn and Co are potentially available in the bioavailable fractions (exchangeable, carbonate and Fe-Mn oxide bound fractions) indicating their importance in toxicity whereas rest of the metals viz. Fe, Cu, Zn and to some extent Cr are largely available in residual phase although they are available in other fractions. The main source of metals to the estuary is mining and its associated activities in the study area. Chemical speciation by sequential extraction procedure has helped in assessing the mobility, bioavailability, diagenesis and toxicity of metals and hence giving a better insight into the ultimate fate of pollutants, which are introduced into the estuarine environment. To understand the risk of the metals to the sediment dwelling organisms the data were compared with the Sediment Quality Values (SQV) using SQUIRT. Also, correlation and Factor analysis were carried out to understand the associations of metals in the different fractions with sand, silt, clay, organic carbon and with other metals.     

Status of Heavy Metals in Water and Bed Sediments of River Gomti – A Tributary of the Ganga River, India

The concentrations of cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc in water and bed sediments of river Gomti have been studied in a fairly long stretch of 500 km from Neemsar to Jaunpur. Grab samples of water (October 2002–March 2003) and bed sediments (December 2002 and March 2003) were collected from 10 different locations following the standard methods. The river water and sediment samples were processed and analyzed for heavy metals viz., Cd, Cr, Cu, Fe, Pb, Mn, Ni, and Zn, and using ICP-AES. The heavy metals found in the river water were in the range: Cd (0.0001–0.0005 mg/L); Cr (0.0015–0.0688 mg/L); Cu (0.0013–0.0.0043 mg/L); Fe (0.0791–0.3190 mg/L); Mn (0.0038–0.0.0973 mg/L); Ni (0.0066–0.011 mg/L); Pb (0.0158–0.0276 mg/L); and Zn (0.0144–0.0298 mg/L) respectively. In the sediments the same were found in the range: Cd (0.70–7.90 g/g); Cr (6.105–20.595 g/g); Cu (3.735–35.68 g/g); Fe (5051.485–8291.485 g/g); Mn (134.915–320.45 g/g); Ni (13.905–37.370 g/g); Pb (21.25–92.15 g/g); and Zn (15.72–99.35 g/g) of dry weight respectively. Some physico-chemical parameters viz., pH, total solids, total dissolved solids, total suspended solids, dissolved oxygen, biological oxygen demand, chemical oxygen demand, hardness etc. were estimated as these have direct or indirect influence on the incidence, transport and speciation of the heavy metals. Based on the geoaccumulation indices, the Gomti river sediments from Neemsar to Jaunpur are considered to be unpolluted with respect to Cr, Cu, Fe, Mn, and Zn. It is unpolluted to moderately polluted with Pb. In case of Cd it varies from moderately polluted to highly polluted. As far as Ni is concerned the sediment is very highly polluted at Barabanki and Jaunpur D/s. No correlation was found between enrichment factor and geoaccumulation index.     

Trace elements as tracers of environmental pollution in the canal sediments (alluvial formation of the Danube River, Serbia)

The purpose of this study was to examine the levels of trace elements and to discuss the origin and mobility of these contaminants in the canal sediments (alluvial formation of the Danube River). The most significant fractions binding all of the studied elements were oxides and silicates. The high proportion of elements in the residual fraction and the generally low contents of extractable elements reflected the background geochemical conditions. The contents of trace elements (except Hg and As) were dominantly controlled by the presence of Fe and Mn oxides as well as by the grain size and the geochemical composition of the sediment. The studied alluvial sediments were not heavily contaminated; there were only few sites where an anthropogenic influence on the concentrations of some metals (Cu, Cd, Zn, and Pb) was noticed. The results from this study show that impact of Pan?evo industrial zone on the quality of the Danube River and its contamination with trace element is minor.     

Origination and assessment of metal pollution in Qarechay River bed sediments

In the present investigation, bulk and chemical partitioning of elements (Cu, Mn, Ni, Zn, Fe, Ca) together with organic matter as a loss in ignition in the Qarechay River bed sediments have been studied. The concentration of metals in Qarechay River bed sediments is governed by the geological units of the study area. The study of anthropogenic portion shows that a small proportion of elemental concentration belongs to this phase. However, Mn has a large portion of anthropogenic sources (43 %). Also, Mn has a share of 13.6 % in sulfide fractions. This result indicates that Mn is a highly mobile element and can easily enter the water column. The presence of Mn in sulfide fraction might be indicative of initial stages of conversion of oxidation state into reduction in Qarechay River. Share of metals in anthropogenic portion is in the following order: Mn (43 %)?>?Cu (19 %)?>?Zn (10 %)?>?Ni (3 %)?>?Fe (0 %). Organic metallic bonds are not significantly present in the study area. Geochemical index (I _geo), pollution index (I _poll), enrichment factor (EF), and pollution load index (PLI) values are indicative of a clean environment throughout the river course. These values are in well agreement with results of chemical partitioning data. Eventually, based on the results of chemical partitioning, regional standard of elements for Qarechay River bed sediments has been established.     

Heavy metal contamination in the Delhi segment of Yamuna basin

Concentration of heavy metals (Cd, Ni, Zn, Fe, Cu, Mn, Pb, Cr, Hg and As) in the waters of River Yamuna and in the soil of agricultural fields along its course in Delhi are reported from 13 sites, spread through the Delhi stretch of Yamuna, starting from the Wazirabad barrage till the Okhla barrage. Varying concentration of heavy metals was found. Peaks were observed in samples collected downstream of Wazirabad and Okhla barrage, indicating the anthropogenic nature of the contamination. The Wazirabad section of the river receives wastewater from Najafgarh and its supplementary drains, whereas the Shahdara drain releases its pollution load upstream of the Okhla barrage. Average heavy metal concentration at different locations in the river water varied in the order of Fe>Cr>Mn>Zn>Pb>Cu>Ni>Hg>As>Cd. The river basin soil shows higher level of contamination with lesser variation than the water samples among sampling locations, thereby suggesting deposition over long periods of time through the processes of adsorption and absorption. The average heavy metal concentration at different locations in soil varied in the order of Fe>Mn>Zn>Cr>Pb>Ni>Hg>Cu>As>Cd.     

Heavy metal concentrations in water, suspended matter, and sediment from Gökova Bay, Turkey

The contents of heavy metals (Fe, Mn, Pb, Cu, Cd, and Hg) dissolved in water and suspended solids of Gökova Bay—partly and fully sampled in 2005 and 2006, respectively—are quite higher than the average values encountered in uncontaminated sea water. The high concentrations are associated with terrestrial inputs from the mining zones and anthropogenic (domestic + industrial) sources. Moreover, the distribution of Fe and Cu is affected by primary production because these elements function as nutrients in biological activities. The Cr, Ni, and Fe concentrations of surface sediments are above the shale average. The Cr and Ni contents of surface sediments representative of river mouths strongly correlate with total phosphorus contents. In a sulfide-poor environment, Pb and Cu were concentrated at a higher ratio in surface sediments than Cd, probably due to higher stabilities of their surface complexes with amorphous iron oxides and clay minerals existing as major components in the sediments. The exceptional enrichment of Zn may be attributed to double oxide formation with amorphous iron oxides in sediments. The high metal values are most probably caused by terrestrial inputs from anthropogenic sources and the mining zones at the southeast part of the bay. The Al, Mn, Pb, Cu, Zn, and Hg contents are below the shale average. The low values have possibly originated from the coarse-grained sandy sediments having a low affinity for metals. There are no distinct differences in the metal distributions in water and suspended matter between the years 2005 and 2006 in the bay, probably due to low sedimentation rates.     

Fraction characteristics of rare earth elements in the surface sediment of Bohai Bay, North China

Surface sediment samples were collected at 27 stations of Bohai Bay, North China. Sequential extractions were carried out in this study. REE were leached out from four labile fractions: Exchangeable (L1), bound to carbonates (L2), bound to Fe–Mn oxides (L3), bound to organic matter (L4), and the remainder was residual (R5). The total contents of REE fluctuate slightly in Bohai Bay, and are mainly concentrated in the middle region, showing relatively higher levels in the north than that in the south of Bohai Bay. Percentages of L1, L2, L3, L4, and R5 for REE suggest that the residual fraction accounts for the major component of REE, whereas Fe–Mn oxides also play important roles in combining labile REE. As the REE complex is not stabilized, the competition of complex could induce dissociation of the complex and redistribution of the REE in various environments. According to REE patterns and Y/Ho ratios of samples, REE are not anthropogenic or oceanic sources but riverine input, whereas suitable environment varieties can slightly affect the patterns and fractionations of REE. As powerful tracers for the variable of environment, higher anomaly of Eu and Ce in southern regions indicates a greater reduction in the condition of surface sediment in the south than that in the north of Bohai Bay.     

Heavy metals partitioning in sediments of the Kabini River in South India

Cu, Cr, Fe, Mn, Ni, Pb, and Zn in the sediments of the Kabini River, Karnataka, India was studied to determine the association of metal with various geochemical phases by sequential extraction. The variations of heavy metal concentration depend on the lithology of the river basin and partly on anthropogenic activities. The Kabini River sediments are dominated by Sargur supracrustals with amphibolites, gneisses, carbonates, and ultrabasic rocks weathering into gneissic and serpentine soils carrying a natural load of cationic heavy metals. The source of heavy metals in the Kabini riverbed sediments is normally envisaged as additional inputs from anthropogenic over and above natural and lithogenic sources. Geochemical study indicates the metals under study were present mostly in the least mobilizable fraction in the overlying water and it is concluded that heavy metals in these sediments are to a great extent derived from multisource anthropogenic inputs besides geochemical background contributions The results show that lead and chromium have higher potential for mobilization from the sediment due to higher concentration at the exchangeable ion and sulfide ion bounded, also Cu and Pb have the greatest percentage of carbonate fraction, it means that the study area received inputs from urban and industrial effluents. Association of the Fe with organic matter fraction can be explained by the high affinity of these elements for the humic substances. Further, Zn and Ni reveal a significant enrichment in sediment and it is due to release of industrial wastewater into the river. These trace metals are possible contaminants to enter into aquatic and food chain.     

An assessment of heavy metal contamination in soils of fresh water aquifer system and evaluation of eco-toxicity by lithogenic implications

The chemistry of heavy metals in sediments with respect to bio-availability and chemical reactivity is regulated by pH, texture, and organic matter contents of the sediments and specific binding form and coupled reactivity of the metals within. To focus on the metal distribution (Fe, Mn, Pb, Cd, Zn, Co, Cu, and Cr) and behavior in a fresh water aquifer system along with the ecological toxicity parameters, a four-step sequential extraction method was applied on 18 Eastern Ghats’ type sediments from fluorosis-hit Nayagarh district, India. Geo-accumulation index of metals in the sediments indicates that they are practically uncontaminated and/or less contaminated with and Fe, Mn, and Cu; contaminated to moderately contaminated with Pb, Zn, and Cr; and strongly contaminated with Cd. Rather, more than 80 % recovered Cd metal concentration in sediments constitute the labile fractions. Temporal clustering of metal fractions indicates transition metal fraction distribution claiming the sediment pH regulation. Similarly, base metal distribution accounts for organic carbon and soil conductivity due to their greater availability in exchangeable and sulfide fractions. Correlation analysis and factor analysis scores demonstrate lack of inter-relationship between transition group and base metal fractions. High fluoride concentration in ground water is associated with high sodium-bicarbonate-iron affinity with elevated pH values (i.e., >7.0) and high positive factor score with the total iron concentration in ground water.     

The success of elutriate tests in extended prediction of water quality after a dredging operation under freshwater and saline conditions

Dredging simulation by elutriate tests accurately predicted concentrations of Hg, Cu, Mn and Fe released to the water column from contaminated sediment to within 1 order of magnitude. Hg and Cu concentrations increased by up to 7-fold after dredging, but declined to background concentrations within 48 h. Maximum loadings of Hg and Cu coincided with Fe and total organic carbon (TOC) water column concentrations, suggesting Hg and Cu are adsorbed onto particulates of Fe oxides and organic material. Seasonal changes in redox potential and temperature did not significantly affect metal release from sediments. Saline water did not cause significant increases in contaminant release from sediments to the water column over that observed for freshwater. Water quality standards of 1 µg l^–1 Hg and 28 µg l^–1 Cu as annual averages were not breached by dredging operations. Long-term effects of dredging on Hg and Cu availability, due to deposition of contaminated material as surficial sediments, is, however, of concern.     

Heavy metals in bottom sediments of Lake Umbozero in Murmansk Region, Russia

Sediment cores collected from different locations of Lake Umbozero were studied with respect to concentration and mobility of trace and heavy metals Co, Cu, Fe, Mn, Ni, Pb, U, and Zn. Lake Umbozero is the second largest lake in the Murmansk Region and subjected to contamination by air-borne emissions and river transportation from the nearby metallurgical and mining industries. Unlike its neighboring, more industry-prone Lake Imandra, Lake Umbozero is relatively unexplored with respect to its state of pollution. In our study, metal distribution in sediments was found to vary with respect to the cores, although in general the concentrations were at the same level throughout the lake indicating uniform horizontal distribution of metals. When compared to Lake Imandra, the concentrations of most of the metals studied were significantly lower and represented the levels in sediments measured in lakes of Kola Peninsula located further off from industrial pollutant sources. An exception was Pb the concentration of which was at the same level as in Lake Imandra, probably due to long-distance transport. Sediment layers were subjected to four-step sequential extraction procedure to reveal the metal distribution in soluble, exchangeable, acid-soluble, and residual fractions. Indicative of their potential higher lability, Mn, U, and Zn were generally found in exchangeable fraction; as also Mn and U extensively in the acid-soluble fraction.     

Distribution and chemical partitioning of heavy metals in marine near-shore sediment cores: a case study from the Xugou, Lianyungang, China

The concentrations and chemical partitioning of heavy metals (Co, Cr, Ni, Zn, Cu, and Pb) in the marine near-shore sediment cores were investigated. Typically, the mean concentrations from Core B sediment samples were 98.6, 21.1, 47.0, 46.4, 107.6, and 31.9 mg kg^???1 for Cr, Co, Ni, Cu, Zn, and Pb, respectively. The heavy metal concentrations were normalized to commonly used reference elements Al, Li, Sc, and total organic carbon. Based on Pearson coefficients, Li was found to be a good normalizer for Co (r?= 0.974), Cr (r?= 0.967), Ni (r?= 0.898), and Zn (r?= 0.929) in 80 sediment samples from three sampling sites. However, the correlation coefficients between Li and Cu, and Li and Pb were relatively low. Multivariate statistic approaches (Principal Component Analysis and Cluster Analysis) were adopted for data treatment, allowing the identification of two main factors controlling the heavy metal variability in the sediments. Heavy metals in the enrichment sections were evaluated by a sequential extraction method for possible chemical forms in sediments. The results showed that the residual, Fe/Mn oxides and Organic/sulfide fractions were dominant geochemical phases in the enriched sections, indicating low bioavailability of heavy metals in sediments.