Factors Affecting Metal Partitioning During Resuspension of Sediments from the Detroit River

The release of previously deposited substances from sediments may represent a significant source of contaminants to the overlying water. Of special concern is the partitioning between aqueous- and sediment-phase heavy metals in response to resuspension events induced by hydrodynamic forces. In this paper results from a set of field experiments are reported in which sediment cores from three stations in the Trenton Channel of the Detroit River were artificially resuspended. Statistical analysis of the data indicated that the concentrations of the dissolved metals Cd, Co, Cu, Ni, Pb, and Zn in the overlying water varied inversely with pH (p<.05) and directly with time when the pH was below 7.5. In addition, dissolved metals were consistently lower at the higher frequency of mixing. Only Zn showed a direct correlation between total and dissolved concentrations although all other metals revealed an increased positive correlation at the higher mixing rate. These results are interpreted in terms of surface sorption reactions, particle size distributions, and mass transfer controls on metal-sediment reaction rates.     

南昌市湖泊重金属源识别及污染特征风险评价

为了解南昌市湖泊重金属污染特征现状,论文以青山湖、象湖及前湖为研究对象,在分析湖泊水体及沉积物重金属Cr、Ni、Cu、Zn、Cd、Pb水平的基础上,采用因子分析、地质累积指数与综合潜在生态风险指数对湖泊重金属污染水平进行评价,并结合主成分分析等统计方法判别各研究水域重金属污染源。结果表明水域中Cr、Cd与Pb为主要重金属污染元素,前湖面临着最为严重的水体重金属污染。沉积物中Ni、Cu、Zn、Cd、Pb存在不同程度风险,各湖泊中沉积重金属风险程度从大到小均为Cd>Cu>Pb>Ni>Zn。前湖生态风险程度最大,其次是象湖。主成分分析表明湖泊重金属主要来源于交通运输与废水废气排放。因此为避免进一步污染,应合理规划交通,控制汽车尾气排放,提升污水治理水平。     

太子河沉积物重金属污染地积累指数法评价

沿太子河布置34个采样断面,取沉积物样品对其重金属（Cu,Zn,Pb和Cd）含量进行检测和分析,并应用地积累指数法对太子河沉积物重金属污染进行了评价。结果表明：太子河上游断面（本溪市区段和葠窝水库部分断面）沉积物中重金属含量较高;Cd的污染偏重,Cu和Pb其次,Zn无污染;与10年前相比,太子河本溪市区段重金属污染程度有所缓解。     

Distribution of Major and Trace Elements in Sediments and Pore Water of Lake Erie

Concentration profiles of major and trace elements were determined in sediment cores from the Central Basin of Lake Erie. The concentrations of trace elements (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn) in the sediments were greatest at approximately 18 cm sediment depth, corresponding to the early 1960s. The concentrations of all elements in the sediments have considerably decreased in the last decade. However, the concentrations of Hg, Pb, and Cd are still about 10, 5, and 4 times greater, respec, than those in the pre-industrial sediments. The profiles of dissolved concentrations of the trace ele in pore water were characterized by maxima below the sediment-water interface, dropping off rapidly within the zone of reduced sediments. Concentrations of dissolved trace elements below the sediment-water interface are about one order of magnitude greater than those in the lake water. Conservative estimates of benthic fluxes ranged from 0.04 /μg/cm².y to 194 /μg/cm².y for Cd and Fe, respectively. Upward diffusive remobilization from sediments to lake water is a significant transport process in the Central Basin of Lake Erie and may play an important role in the transport of trace elements from the sediments.     

Cd, Cu and Zn mobility in contaminated sediments from an infiltration basin colonized by wild plants: the case of Phalaris arundinacea and Typha latifolia

Infiltration basins are shallow reservoirs in which stormwater is temporarily collected in order to reduce water volume in downstream networks. The settling of stormwater particles leads to a contaminated sediment layer. Wild plants can colonize these basins and can also play a role on the fate of heavy metals either directly by their uptake or indirectly by modification of physico-chemical characteristics of the sediment and therefore by modification of the mobility of heavy metals. The aim of this study, carried out in a vegetated infiltration basin, is to assess Cd, Cu and Zn mobility in two zones colonized by different species, Phalaris arundinacea and Typha latifolia. The study was carried out using three single chemical extractions: CaCl2 for the exchangeable phase, acetate buffer for the acido-soluble fraction and diethylenetriamine-pentaacetic acid (DTPA) for the fraction associated to the organic matter. Zn and Cd are mainly associated to carbonated and organic matter phases of the sediment. Moreover, acetate buffer-extractable Zn contents are strongly correlated to carbonates content in the sediment. DTPA-extractable Cu contents are strongly correlated with organic carbon sediment contents. We have also noted that extractable contents were significantly different between both zones whatever the metal.     

Assessment of sediment quality and pore water ecotoxicity in Kebir Rhumel basin (NE-Algeria): a combined approach

The objectives of this study are to use different approaches to assess the current pollution status in the wadis of the Kebir Rhumel basin. First, sediment trace metal contents were measured by flame atomic absorption spectroscopy. Then, sediment quality was assessed on the basis of contamination assessment indexes such as: Geoaccumulation Index (Igeo), Contamination factor (C(f)), Contamination degree (C(d)), Sediment Pollution Index (SPI) and SEQ guidelines (Consensus Sediment Quality Guidelines). In addition, several toxicity tests (Daphnia magna mobility inhibition acute test-48 h, Aliivibrio fischeri luminescence inhibition acute test - 15/30 mn and Pseudokirchneriella subcapitata growth inhibition chronic test - 72 h) were conducted to assess sediment pore water ecotoxicity. Trace metal concentrations followed the order: Mn > Zn > Pb > Cr > Cu > Ni > Co > Cd. Indexes used indicate varying degrees of sediment quality. Igeo, C(f), C(d) and SPI reveal a polymetallic contamination dominated by two or more elements in which Cd, Cu and Pb are of greatest concern. SEQ guidelines showed that biological effects on fauna would likely be observed occasionally and/or frequently for Cd, Cr, Cu, Pb and Zn contents. Test organisms exposed to sediment pore water showed that the algal P. subcapitata test was more sensitive than the D. magna and A. fischeri tests. Hence, algal growth inhibition proved to be the most sensitive response to contaminants present in sediment extracts but a significant relationship with trace metal contents was not demonstrated.     

引滦入津工程黎河河道表层沉积物重金属形态及风险分析

对引滦入津工程黎河段表层沉积物和两岸尾矿中重金属特征进行研究。结果表明:受两岸尾矿砂影响,黎河河道表层沉积物的矿物组成及重金属特征与尾矿砂相一致,重金属含量依次为FeMnZnPbCuCd。重金属形态分析表明:Fe、Mn、Cu、Zn残渣态占绝对优势,Pb以可交换态和残渣态为主,Cd仅有可交换态和碳酸盐结合态。采用风险评价准则法(RAC)和平均沉积物质量基准系数法(SQG-Q)评价,结果均表明表层沉积物中Pb和Cd对环境具有非常高风险,其潜在的毒性风险应引起重视。     

Distribution of Major Elements and Metals in Sediment Cores from the Western Basin of Lake Ontario

An investigation was made of the relationship between the changes in metal concentrations in sediments with the distance from the Niagara River mouth and the chemical and physical characteristics of the sediments. Sediment cores were obtained at nine sampling stations in the western basin of Lake Ontario. In addition, surface sediment was collected at three stations on the Niagara Bar. Minerals present at all stations were silica, feldspars, illite/muscovite, chlorite, kaolinite, and calcite. Dolomite was found at some sampling stations as grains of 2 to 63 μm size. Significantly elevated concentrations of calcite (up to 20%) in the surface sediment (about 0 to 10 cm) at four sampling stations in the western basin and in the entire 25-cm sediment column at the Niagara River mouth indicated increased input of this mineral into Lake Ontario during the past 100 years. Furthermore, sediment concentration profiles of Zn, Pb, Cr, Cu, Ni, and especially Hg at all sampling stations indicated major transport of metals associated with the clay- and silt-size particles from the Niagara River into Lake Ontario (especially north-north-east and east of the river mouth). A significant decrease in Hg loading from the Niagara River during the past 20 years was also observed. Although smaller in magnitude, a similar decrease was found for Pb, Zn, Cr, Ni, and Cu loading. However, elevated Hg concentrations (up to 7 μg g～^l above background values) existed in the surface 10 cm of sediment at eight sampling stations.     

Comparative spatial metal concentrations and partitioning in bottom sediments of two tropical freshwater lake basins,Kenya

Metal concentrations in the water, sediments and biota in alkaline, near neutral water tropical freshwater lake basins were determined and a comparative analysis made on the spatial and accumulated trace metal concentrations, and geochemical partitioning of iron (Fe), manganese (Mn), copper (Cu), chromium (Cr), zinc (Zn), nickel (Ni), cadmium (Cd) and lead (Pb) in bottom lake sediments. Variable accumulated levels were found in the analysed sediments and aquatic biological tissues. Metal partitioning data in the present study from the two areas exhibits similar trends in magnitude. The residual fractions retained relatively higher amounts of metals. Relatively higher contents of Pb, Cr and Cu were found in Lake Victoria sediments. Cd, Ni, Mn and Pb are of concern because a higher percentage of these metals were retained in the more bioavailable fractions in Lake Naivasha. Total levels of sediment mercury were comparable for the two lake basins. Metals were found in significant levels in the tissues of aquatic organisms, highlighting the potential risks to other levels within the aquatic food chain. Although the exposure risk was not evaluated, it is important to continue monitoring these elements in fish, as sediments were found to contain considerable quantities of the metals. Numerous sediment extraction techniques data applied for evaluating metal partitioning in sediments cannot be compared because of the use of different methods. Nevertheless, the information is still useful in differentiating and understanding pollution loads from natural versus anthropogenic sources and their associated risks.     

Trace metal levels in sediments deposited in urban stormwater management facilities.

Characteristics of solids recovered from stormwater best management practice (BMP) facilities, including stormwater ponds, constructed wetlands, an infiltration basin, a biofilter, a stormwater treatment clarifier, and three-chamber oil and grit separators were described with respect to their metal chemistry. The reported trace metal concentrations in BMP sediments were assessed against the Ontario Sediment Quality Guidelines. Between 80 to 100% of all samples were marginally-to-intermediately polluted by Cd, Cr, Cu, Fe, Pb, Mn, Ni and Zn. Severe pollution of sediments was noted for Cr (122 microg/g), Cu (151 and 196 microg/g), Mn (1,259 and 1,433 microg/g), and Zn (1,116 microg/g), at several facilities studied, and even higher levels of metals were reported in the literature for certain oil and grit separators. With respect to individual BMPs, the severe pollution was found in sediments from oil and grit separators (for Cd, Cr, Cu, Pb and Zn), the stormwater clarifier sludge (Cu, Mn and Zn), a biofilter (Cu and Mn), an industrial area stormwater pond (Cu only), and a commercial/residential pond (Cr only). Finally, the chemical pollution of pond sediment triggered toxicity testing at some of the facilities studied, and sediment toxicity was confirmed at several sites.     

Biogeochemical Investigation of Big Creek Marsh,Lake Erie,Ontario

Geochemical composition of sediment, uptake of nutrients and metals by macrophytes, and nutrient and metal concentration in the water was investigated at six selected stations in Big Creek Marsh, Ontario. The maximum concentrations of Pb, Ni, Cu, Cr, and Zn in marsh sediment (86, 48, 38,119, and 383 μg/g dry weight, respectively), were lower than the concentration of these metals found in fine-grained surficial sediments of Lake Erie, and maximum concentration of As and Hg in marsh sediment (112 and 0.930 μg/g dry weight, respectively) were higher than As and Hg concentration in most of Lake Erie surficial sediments. Occurrence of DDT metabolites in marsh sediment reflects extensive use of DDT in the Big Creek drainage basin prior to 1970. Increase of total Kjeldahl Nitrogen and NH₄-N in marshwater was observed at a few sampling stations in November. Submerged macrophytes Myriophyllum, Chara, and Elodea sps. accumulated larger quantities of Pb, Cu, Ni, Cd, and Cr than emergent macrophytes at the stage of maximum development. Correlation between Ca and Pb, Cu, Ni, and Cr concentration in sampled macrophytes was observed; however, there was no correlation between Ca and Zn in these plants.     

Metals,acid-volatile sulfides,organics, and particle distributions of contaminated sediments

An overview of key physical/chemical parameters for contaminated sediments is presented. While sediment cores from remote lakes show little or no enrichment with heavy metals (Pb, Hg, Cd, Zn, Cu) and PAHs in top layers, the contamination near industrial areas is more significant. Cd in more bioavailable geochemical phases can occur in response to Cu inputs to sediments, and aeration during dredging operations of anaerobic sediments can reduce the pH causing release of heavy metals. The toxicity of anaerobic sediments to benthos can be effectively predicted based on interstitial water concentrations and the molar ratio between simultaneously extracted metals and acid-volatile sulfides (SEM/AVS). The toxicity of PAHs and other organics can be predicted based on equilibrium partitioning. Principal component analysis indicates that PAHs are associated with organic carbon and silt, and PCBs with inorganic clay. Finally, formulated reference sediments appear to be useful in toxicity testing by creating uniform parameters matching field conditions, and by isolating the effects of specific contaminants.     

Accumulation and Transport of Sediment Metals by the Vertically Migrating Opossum Shrimp,Mysis relicta

This study examined the accumulation of metals (Al, As, Cd, Cu, Cr, Fe, Ni, V, and Zn) in the opossum shrimp Mysis relicta from sediments to understand the contribution of sediment metals to overall body burden metal contents. Metal biota-sediment accumulation factors, tissue depuration ratios, and sediment metal assimilation efficiencies were calculated to examine the extent to which mysids accumulate metals from sediments contained within their guts. Results were then used to estimate the concentrations of metals transported to the water column and to fish because of mysid diel vertical migration. Results showed that Al, Cr, Fe, and V were readily depurated (34 to 73% of total body burden) and were not preferentially accumulated in mysid tissues (Biota Sediment Accumulation Factor, BSAF < 0.009). In comparison, As, Cd, Cu, and Zn were not readily depurated (9 to 26% of total body burden) and were more readily accumulated in mysid tissues (BSAF > 0.037). Nickel shows an intermediate behavior for depuration and accumulation. Calculations suggest that following 12 hours depuration through vertical migration, about 1.57 μg sediment/mysid (0.05% of dry weight of M. relicta) remained as gut contents. As a result, 16 to 50% of the Al, Cr, Fe, Ni, and V and 1.0 to 5.5% of the As, Cd, Cu, and Zn mysid body burden metal content transported to the water column was attributed to sediment in the gut. These results indicate that trace metals (As, Cd, Cu, and Zn) ingested from sediments are poorly accumulated in mysids (calculated AEs ranged from 0.07 for Cr to -11 for Cu) and metals transported by mysids to fish in the water column are primarily associated with mysid tissues.     

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.     

Hydrocarbons and heavy metals fixed to the lift station sediment of the Paris combined sewer network.

This work aims to characterise the pollutant loads fixed to the Lift Station (LS) sediments. Firstly, levels of n-alkanes, PAH and heavy metals (Fe, Zn, Cu, Pb and Cd) of LS sediments were assessed, and were found of the same order of magnitude as those reported for street runoff. In addition, investigations on LS sediment reveal that n-alkane distributions reflect the combination of biologic and petrogenic inputs, while PAH distributions indicate a major pyrolytic origin with traces of petrogenic contaminations. The metallic fingerprints also attest to the important contribution of road traffic emissions. Secondly, a comparison between LS sediment and the Gross Bed Sediment (GBS) pollutant contamination was established in order to optimize the in-sewer deposits management. For hydrocarbons, a similar contamination between both sediments is found. For the heavy metals, this comparison indicates a similar Fe and Zn content, while Pb, Cu and Cd contents differ. Indeed, LS sediment shows a higher Cu content, linked to the occurrence of intensive brake lining abrasion, compared with GBS, which reflects a higher Pb and Cd content, owing to the contribution of roof runoff. This result reveals the impact of specific inputs such as road traffic or roof runoff on the in-sewer sediments contamination, and provides a complete overview of the LS sediment contamination. This database could be used by the municipality to optimize their contaminated in-sewer sediment management.     

Role of bottom sediments in the secondary pollution of aquatic environments by heavy-metal compounds

The results of long‐term investigations into the concentrations of some heavy metals (Fe, Mn, Cu, Zn, Pb, Cr, and Cd) in the bottom sediments of the Dnieper reservoirs and the Dnieper–Bug estuary are considered. Maximum quantities of the metals studied are characteristic of southern water bodies located within industrial zones (the Zaporozh’e and Kakhovka reservoirs as well as the Dnieper–Bug estuary). The highest concentrations of the metals studied occurred in the clay silts (Fe, 11 600–32 400; Mn, 1504–3450; Cu, 38.9–85.5; Zn, 89.8–186.5; Cr, 48.6–193.0; and Cd, 1.9–4.4 mg kg^‐1 dry weight). Accumulation of heavy metals in the bottom sediments is an important factor in the self‐purification of aquatic environments. However, this process is reversible and therefore provides a constant threat of secondary water pollution. Secondary water pollution is observed in summer and autumn when water consumption increases. The concentrations of heavy metals increase by a factor of 1.5–3 after the drawdown of the water level. The main reason for the rise in the concentrations of metals is exchange between the bottom sediments and the water column. The rate of heavy metal migration is connected with the forms of occurrence in solid substrates and pore solutions in the bottom sediments, as well as with physico‐chemical conditions arising at the sediment/water boundary. Therefore, our investigations concentrated on the study of the fractional distribution of heavy metals among solid substrates and their forms of occurrence in interstitial solutions. This distribution depends, most of all, on the chemical properties of metals as well as the chemical and mineralogical composition of the sediments and the chemical properties of pore solutions. Most of the supply of Mn, Zn, Fe, and Cd is associated with oxides and hydroxides of iron and manganese (Mn, 74–93%; Zn, 43–70%; Fe, 27–59%; and Cd, 28–41%). Most copper and chromium is bound to organic matter and to scarcely soluble minerals. In the interstitial solutions studied, metals (except manganese) are found mainly as complex compounds with dissolved organic matter of a different molecular weight. Nevertheless, the fraction of complexes with a relatively low molecular weight (500–5000 Da) prevailed (40–70%). Dissolved manganese in the pore solutions consists chiefly of free (hydrated) ions Mn²⁺ (80–95%). The results obtained were used for a comparative evaluation of heavy metal mobility and the exchange ability of their associated compounds in the bottom sediment–water system.     

Sedimentary Records of Spheroidal Carbonaceous Particles from Fossil-Fuel Combustion in Western Lake Ontario

Spheroidal carbonaceous particles (SCPs) were quantified in three sediment cores collected from depositional areas in the western basin of Lake Ontario to examine the impact of fossil-fuel combustion on sediment metal concentrations. SCP profiles were similar for the three cores showing the initiation of the SCP record deep in the core, followed by a rapid increase to a sub-surface maximum, and a subsequent decrease towards the sediment surface. Subsurface maximum SCP concentrations ranged from 1.97 to 5.61 × 10⁵ per gram dry matter/gDM. For ²¹⁰Pb dated cores, dates for the initiation of the SCP record (1850 ± 10 years), the initiation of the rapid rise in SCPs (1880 ± 13 years), and the SCP subsurface maximum (1961 ± 3 years) agree well. The rapid increase in sediment SCPs also agrees well with the US bituminous coal consumption during this same period (1880 to 1980). SCPs in surface sediments decreased between 55 to 83% from the subsurface maximum (1961 to 1996) in these cores while U.S. coal usage continued to increase. SCP decreases were attributed to the increased use and efficiency of particle collection devices by utilities and industry. Lead, Cr, Cu, and Zn showed significant correlations (r² = 0.63 to 0.94) with SCPs within each respective sediment core. Calculations show that although SCPs are not the major source of anthropogenic metals in Lake Ontario sediments, they may account for between 4 to 55% of the Zn, 1 to 12% of the Cu, 2 to 22% of the Pb and 1 to 18% of the Cr in these sediments.     

Variations in trace elements in bottom sediments of major rivers in Lake Victoria's basin, Kenya

River sediments collected between March 1994 and January 1995 were analysed for iron (Fe), manganese (Mn), zinc (Zn), lead (Pb), copper (Cu), chromium (Cr), aluminium (Al) and cadmium (Cd) in the less than 63 μm grain‐size fraction. The river sediments were characterized by a sandy texture, with a relatively low organic matter (as percentage loss on ignition), ranging 3.5–9.6%. The metal mean range values in μg/g dry weight for the river sediments were: Mn (836–2.10 × 10⁴), Fe (1.09 × 10⁴–9.22 × 10⁴), Al (2.86 × 10³–7.77 × 10³), Zn (34–130), Cu (11–78), Cr (not detected ND–125); Pb (ND–100) and Cd (ND). Temporal variations were significant for Zn, Cr and Pb. There were no significant longitudinal differences in all the elements in rivers Nyando, Nzoia, Yala and Sondu‐Miriu, apart from sediment Fe contents. Relatively high sediment Fe, Mn, Zn, Cr and Al were observed in river Kasat. River Kasat was considered polluted with respect to Mn, Zn and Cr, which were comparatively higher than unpolluted sediments and geochemical background values. This supports similar results on surface water trace element levels. Most of the rivers drain an area of relatively similar lithological characteristics. Therefore, apart from the direct waste input into Kasat river from municipal and industrial sources, lack of specific point sources indicate lithological metal origins with localized variations. A final comparative evaluation of the river sediments’ trace metal pollution was made from the study results. The data is vital for pollution management of the lake as information about metal loadings into the lake ecosystem is lacking.     

台州市安溶泾河道底泥重金属污染特征及生态风险评价

为顺利开展城市河道污染整治工程,有效控制河道底泥引发的二次污染,研究河道底泥污染特征并分析其生态风险具有重要意义.基于台州安溶泾河道底泥检测结果,采用单项污染指数法、潜在生态风险指数法、聚类分析法等多种方法对底泥重金属含量、污染状况、空间分布、生态风险等进行评价.结果 表明:底泥中Cu、Zn、Pb、Cd这4种重金属污染...