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 and Sequential Extraction of Heavy Metals in the Soil of Scrapyard of Discarded Vehicles

Chemical and physical size fractionation of heavy metals were carried out on 20 soil samples from the scrap yard area. Tessier method was used in sequential extraction. Cadmium showed the highest levels among the other elements studied in the exchangeable fraction (about 33%), while other elements showed low levels in this fraction (≥1%). Lead and manganese were mostly found in the Fe–Mn oxide fraction, zinc and iron were mostly in residual fraction, while copper was mostly found in the organic fraction of the soil. Soil samples were size-fractionated into four sizes: 1000–500, 500–125, 125–53, and less than 53 μm. The highest levels of Fe, Cu, Pb, Mn, and Cd were found in the medium fraction (500–125 μm), while zinc showed its highest levels in the fine fraction (125–53 μm). The order of heavy metal load in the size fractions was found to be medium > fine > coarse > silt for Fe, Mn, Cu, Pb, and Cd, where it was found as fine > medium > coarse > silt for zinc.     

Heavy Metal Transport in the Hindon River Basin, India

Total mass transfers of heavy metal in dissolved and particulate form has been determined in the downstream section of river Hindon, an important tributary of river Yamuna (India). The contribution of different point sources to the river Hindon has also been assessed. The river Kali has the largest contribution to the river Hindon. The highest metal loads were related to the highest flow of the river and thereby increased both by surface runoff and sediment resuspension. The contribution of monsoon months to the total transported load was also calculated and it was observed that monsoon months contributes more than 40% of total loading annually for all the metals. The metal fluxes from the river Hindon were compared with other rivers of Indian sub-continent.     

上海市黄浦江表层沉积物重金属污染评价

用沉积物富集系数法和Hakanson潜在生态风险评估法对上海市黄浦江表层沉积物重金属含量进行了评价。结果显示,沉积物中Cd、As和Pb含量富集程度较低,Hg和Cu含量富集程度较高;其分布特征为上游段含量相对较轻,到中游段有所上升,至下游段含量又有所下降,整体呈钟型分布,重金属含量分布规律可能与苏州河对黄浦江下游沉积物的影响和黄浦江中游段有工业污染排放输入有关;河口与内陆河流沉积物中重金属含量存在差异性,河口重金属含量明显下降;调查区37.5%的断面Hg含量潜在生态危害为中等;沉积物富集系数法可用来评价重金属累积程度,而潜在生态风险指数则突出对生物有很强毒性的重金属作用。     

贵州某流域城市河段沉积物及悬浮物重金属污染研究

通过在丰水期对贵州省某流域城市河段悬浮物和沉积物中的重金属含量进行测定,运用单因子指数法、生态风险评价法、因子分析法,初步探讨了该河段Cu、Zn、Pb、Hg、Cd、Cr、Ni及As等8种重金属元素的含量分布、污染特征、潜在生态风险及主要来源。检测结果显示,沉积物和悬浮物中Hg、Cd、Zn、Pb、As的平均含量较高,是贵州省土壤背景值的1.02～16.97倍。单因子指数评价结果表明：在沉积物中,Zn、Pb、As为轻度污染,Hg和Cd为重度污染;在悬浮物中,Cu、Pb、As为轻度污染,Zn为中度污染,Hg和Cd为重度污染。潜在生态风险指数评价结果显示,Hg和Cd的生态风险最大,为主要污染元素。研究区沉积物样品综合生态风险指数(RI)介于183.27～1 393.96,平均值为912.06,总体处于严重生态风险等级;悬浮物样品RI值介于341.53～612.38,平均值为436.85,总体处于重度生态风险等级。其中,沉积物样品重金属平均生态风险等级高于悬浮物样品,支流样品重金属生态风险等级总体上低于干流下游样品。根据因子分析法分析结果,初步推测沉积物及悬浮物Hg、Cd、Cr、Ni含量主要受工...     

往复流河道沉积物重金属的污染特征和风险评估

在往复流现象明显的蕰藻浜中下游河道选择16个采样点,分析研究沉积物性状以及Cr、Cu、Zn、Cd、Ni、Pb、Mn的含量以及分布情况。结果表明:蕰藻浜总体污染程度为中等,其中陈行桥、江杨北路桥以及淞港码头污染较严重。Cr、Cd、Pb、Ni、Cu、Zn和Mn的含量分别为24.0~357.0、0.06~0.69、20.0~85.4、18.2~132、14.2~136、84.6~685、472~1 086 mg/kg。通过分析发现,Pb、Ni、Cu、Zn和Cr总量都具有显著的相关性,很有可能来自同一外源污染,而中游河段的Mn主要来自于沉积物母质。河道两岸以往的工业与生活排污以及往复水流使得重金属污染物在沉积物中聚集是造成重金属污染的潜在原因。运用地累积指数法、潜在生态危害指数法、污染负荷指数3种风险评价法对沉积物重金属进行风险评估,总体来说,3种评价方法都表明Cu的污染程度较严重,Mn的污染较轻。其中地累积指数法结果显示,各重金属的污染顺序为CuZn≥CdPb≥CrNiMn,然而由于Cd本身生物毒性较高,对沉积物生态环境危害贡献率可达到60%;污染负荷指数评价结果发现蕰藻浜下游河段部分断面沉积物达到了极强污染程度,应当受到重视。     

渭河陕西段表层沉积物重金属污染特征及潜在风险

为了解渭河陕西段表层沉积物重金属的污染特征,采用ICP-MS分析了13个采样断面表层沉积物中As、Cd、Cr、Cu、Mn、Ni、Pb和Zn 8种重金属的含量,并对其来源和生态风险进行了评价。结果表明：渭河陕西段8种重金属的平均含量顺序依次为Mn > Zn > Cr > Cu > Ni > Pb > As > Cd;除Ni外的其余7种重金属的平均含量均超过陕西省A层土壤背景值。各断面表层沉积物重金属的潜在生态风险指数（RI）介于111.4~7 043.7,其中23.1%的断面有极强生态风险,46.2%的断面为中等生态风险,其余为轻微生态风险。Cd污染最为严重,对各断面的潜在生态风险介于较强生态风险与极强生态风险之间,对RI的贡献平均为85.2%;其余7种重金属在所有断面均属于轻微生态危害。渭河陕西段表层沉积物As、Cd、Cu和Zn主要为工业与农业来源;Cr和Ni主要为自然来源;Pb和Mn与城市污水和交通污染来源有关。     

Antennal Deformities of Chironomid Larvae and Their Use in Biomonitoring of Heavy Metal Pollutants in the River Damodar of West Bengal,India

Analyses of sediment and water indicate the presence of heavy metal pollutants like lead, zinc, copper, mercury and cadmium of the river Damodar of India. These metals are responsible for causing morphological deformities of antennae and other parts of chironomid larvae. Percentage of deformity correlated positively with the concentrations of Pb in water and sediment (r > 0.6) at the confluence point. A new severity index, SISS_(antenna) has been proposed here to assess deformity at the family or subfamily level.     

海河干流(市区段)表层沉积物重金属污染及变化趋势分析

根据1990—2006年监测资料,对海河干流（市区段）沉积物中重金属的现状和变化趋势进行了分析,采用地积累指数和Hakanson危害指数对海河干流（市区段）沉积物重金属富集现状和对水生生物危害进行评估。结果显示：海河干流（市区段）表层沉积物除Zn外,均呈现污染下降趋势。海河干流（市区段）沉积物中重金属对生物潜在危害顺序为Cd〉Hg〉As〉Cu〉Pb〉Cr〉Zn,各项指标对生物潜在危害性上游大于下游。     

Enrichment and fractionation of heavy metals in bed sediments of River Narmada, India

A metal fractionation study on bed sediments of River Narmada in Central India has been carried out to examine the enrichment and partitioning of different metal species between five geochemical phases (exchangeable fraction, carbonate fraction, Fe/Mn oxide fraction, organic fraction and residual fraction). The river receives toxic substances through a large number of tributaries and drains flowing in the catchment of the river. The toxic substances of particular interest are heavy metals derived from urban runoff as well as municipal sewage and industrial effluents. Heavy metals entering the river get adsorbed onto the suspended sediments, which in due course of time settle down in the bottom of the river. In this study fractionation of metal ions has been carried out with the objective to determine the eco-toxic potential of metal ions. Although, in most cases (except iron) the average trace/heavy metal concentrations in sediments were higher than the standard shale values, the risk assessment code as applied to the present study reveals that only about 1–3% of manganese, <1% of copper, 16–19% of nickel, 4–20% of chromium, 1–4% of lead, 8–13% of cadmium and 1–3% of zinc exist in exchangeable fraction and therefore falls under low to medium risk category. According to the Geo-accumulation Index (GAI), cadmium shows high accumulation in the river sediments, rest of other metals are under unpolluted to moderately polluted class.     

西宁市非采暖季和采暖季PM2.5中14种金属元素特征

于2012年11月采暖季和2013年9月非采暖季,在青藏高原典型城市西宁市4个采样点采集细颗粒物(PM_(2.5))样品,共获得40个有效样品。用微波消解-ICP-MS法、原子荧光法分析了样品中14种重点防控金属。结果表明:14种重点防控金属中Ag、Tl平均质量浓度为0.10~0.50 ng/m~3,Co、Sb、Hg平均质量浓度为0.50~4.00 ng/m~3,V、Cd、Cr、Ni、Cu、As平均质量浓度为4.00~50.0 ng/m~3,Mn、Pb、Zn平均质量浓度为50.0~2 000 ng/m~3。采样期间,采暖季相比非采暖季,PM_(2.5)质量浓度有下降趋势,不同采样区金属元素浓度有增有减。富集因子分析结果表明,重点防控金属元素在非采暖季主要来源于土壤风沙扬尘、机动车尾气和工业排放,采暖季主要来源于土壤风沙扬尘、燃煤、燃油、机动车尾气和工业排放。非采暖季Zn、Ag、Cd、Hg、Tl和Pb富集因子较高,采暖季Zn、As、Ag、Cd、Sb、Hg、Tl、Pb富集因子较高,更容易受到人为源的影响。     

2015—2018年春节期间合肥烟花爆竹燃放对空气质量的影响

根据2015—2018年颗粒物浓度数据、颗粒物组分、激光雷达等资料,分析烟花爆竹燃放对合肥市空气质量的影响。研究发现,随着烟花爆竹禁燃措施力度的加强,2018年合肥市烟花爆竹对空气质量影响较2015—2017年显著下降,2018年春节期间PM₁₀与PM_2.5峰值浓度比2017年分别下降44. 4%和52. 9%,污染峰值容易出现在除夕和初一前后。春节期间合肥市大气污染总体上呈现自东北到西南逐渐减轻的趋势,周边县(市)空气质量的污染程度比城区更加严重。烟花爆竹的燃放导致空气中金属元素浓度和SO₄^2-浓度明显增加,富集因子法发现呈现严重富集重金属元素Sr、Zn、Ba、Cu、Pb、Sn、Sb和其他元素(如K、As)。2018年烟花爆竹禁燃措施力度加强后,K、As、Sn、Sb元素富集程度呈现下降趋势,较高消光系数对应的高度范围较2017年大幅减小,并且污染带厚度显著降低,城区依然可能存在外来污染传输的颗粒物下沉现象,周边大片农村和城乡结合部的烟花爆竹集中燃放同样会导致被其包围的城区空气质量迅速恶化。     

Heavy Metal Pollution Assessment in Sediments of the Izmit Bay, Turkey

Surface sediments in the fraction < 63 μm collected from eight stations along the north coastline of Izmit Bay, north-eastern Marmara Sea, Turkey, were analyzed for major (organic carbon, Al, Ba, Fe and Mg) and trace (As, Cd, Co, Cr, Cu, Mo, Ni, Pb and Zn) elements by using inductively coupled plasma atomic emission spectrometry (ICP-AES). Sediments heavily contaminated are evaluated by the Sediment Quality Guidelines (SQG) of US EPA. The results were compared with the marine sediment quality standards (SQS), as well as literature values reported to assess the pollution status of the sediments. The enrichment factors (EFs) were calculated to evaluate actual level of contamination for all the elements using the earth crust as reference matrix, based on elemental values by Mason which show a normal pattern near to unity. The analysis revealed two groups of elements: (i) Arsenic, Cd, Pb, and Zn are the most enriched elements; (ii) Barium, Co, Cr, Cu, Fe, Mg, Mo and Ni are at background levels. The results show that road traffic run-offs, paint industries and coal combustion are among the most significant sources.     

望虞河西岸河网区沉积物营养盐和重金属污染时空分布特征

以无锡市望虞河西岸河网区为研究区域,于2018年12月—2019年9月分冬、春、夏、秋4个季节采集了上覆水和沉积物样本,研究氮磷营养因子在沉积物-上覆水界面的释放规律,探究主要水质指标、沉积物氮磷和重金属含量的时空分布特征。结果表明:研究区域内的水质状况不佳,主要是氮含量超标,污染严重的点位集中在人类活动较为密集的市区和工业区;受上覆水氮磷浓度、溶解氧浓度等变化的影响,沉积物营养盐含量季节变化明显,污染状况较为严重,75%的点位属于中度和重度污染;沉积物重金属含量季节变化不显著,部分重金属的空间分布特征相似,污染程度排序为Zn>Cd>Cu>Pb>Ni>Cr>As。     

涪江绵阳段表层沉积物重金属污染特征及风险评价

为准确掌握涪江绵阳段表层沉积物重金属的污染特征,分析了7个监测断面表层沉积物中Cd、Se、Mn等19种重金属质量浓度,采用地累积指数法、潜在生态风险评价法和污染负荷指数法评估了沉积物重金属的污染程度及潜在风险。结果表明:涪江绵阳段表层沉积物中Se、Cd、Ba和Hg等元素含量显著超过其土壤背景值,重金属的污染程度依次为Se＞Cd＞Ba＞Hg＞Mo＞Mn;潜在生态风险评价和污染负荷指数评价结果均显示,断面的污染程度排序为楼房沟＞李家渡＞福田坝＞丰谷＞涪江铁路桥＞百顷＞平武水文站断面。楼房沟断面沉积物微观形貌主要为片状或块状,物相主要为石英及少量白云母、方解石和菱锰矿等,与铅锌矿、电解锰渣等主要矿物组成相似,重金属主要来源为尾矿渣在河床的沉积及金属矿开采等外源输入。     

Study of Geochemical Association of Some Trace Metals in the Sediments of Chilika Lake: A Multivariate Statistical Approach

In order to establish the natural processes and geochemical factors responsible for enrichment of trace metal ions (Cu, Co, Ni, Zn and Cr) with respect to textural parameters (sand, silt and clay weight percentages) along with depth, multivariate statistical approach has been carried out for sediments in different water zones of Chilika lake, the largest brackish water lagoon in Asia. The rotated varimax factor results reveal that Cobalt enrichment is controlled by both textural parameters as well as adsorption mechanism. In fresh and saline water region, textural parameters and in mixed water, adsorption phenomenon predominates. Zn in fresh water is related to clay, whereas it is in adsorbed state in mixed water. Cu in fresh water sediments is in absorbed state and in mixed water it is related to depth and Co concentration. Cr does not show any specific association in fresh water, but in both mixed and saline water it is associated with clay minerals. Although both textural parameters and adsorption mechanism play an important role for the enrichment of trace metal ions in these lagoonal sediments, their relative importance varies with specific metal ions as well as the water quality. Sequential extraction technique was used to characterize the various forms of metals in the < 63μ size sediments of Chilika lake. The concentrations determined indicated selective accumulation of the various metals in the different phases with spatial variability in different water zones. Slightly higher availability of Co and Zn near Balugaon township in exchangeable phase may be related to anthropogenic activities. Among the non-lithogenous (NL) phases, reducible phase associated with higher concentration of Ni, Cu and Cr. Organic bound Zn and Co contributed highest percentages among NL fractions. Residual fraction contributed more than 50% in most of the cases, reflected the predominance of physical weathering, high erosion rate along the drainage basin.     

Fractionation of heavy metals and phosphorus in suspended sediments of the Yamuna river,India

The Yamuna river is the largest tributary of the Ganges river system. It originates in the Himalayas and flows through a varied geological terrain encompassing a large basin area. Metals Fe, Mn, Pb, Zn, Cu in different chemical fractions of suspended sediments such as exchangeable, carbonates, Fe–Mn oxides, organics and residual fractions were studied. Phosphorus associated with different chemical forms are discussed. The metals are mostly associated with residual fractions in the sediments followed by organics, Fe–Mn oxides, exhangeable and carbonates. Intensive use of chemical fertilizers and pesticides in agriculture in the basin affects the high inorganic phosphorus content in sediments.     

Distribution and Statistical Analysis of Leachable and Total Heavy Metals in the Sediments of the Suez Gulf

The concentrations of nine heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pd and Zn) in the labile and total fractions of muddy and sandy sediment samples collected from twelve sites in Suez Gulf during April 1999 were studied to evaluate the pollution status of the Suez Gulf. The enrichment factors (EF) for each element were calculated. There are extremely high concentrations of Cd, Ni, Pb and slightly concentration of Cr and Cu in both muddy and sandy sediments. The concentration of Zn was moderately high and can be considered as seriously contaminate Metal pollution index (MPI) shows high values ranged between 46 to 156 and 40 to 232 for both sandy and muddy sediments, respectively. Concentrations of heavy metals were normalized against iron for total fraction in both of sandy and muddy sediments. Principal component analysis (PCA) was studied on the data matrix obtained and represented three-factor model explaining 92.22% for labile and 88.82% for total fractions of muddy sediment. The main source of contamination is the offshore oil fields and industrial wastes. This is largely a result of ineffective and inefficient operation equipment, illegal discharge of dirty ballast water from tankers and lack of supervision and prosecution of offenders.     

Metal Contamination in Zebra Mussels (Dreissena Polymorpha) Along the st. Lawrence River

In order to evaluate the use of zebra mussels as biomonitors for metal bioavailability in the St. Lawrence River, we tested the hypothesis that the concentrations of 11 metals in zebra mussels vary significantly between sites along the river and that the season of collection and body size affect metal bioaccumulation. Mussels were collected at 14 sites during June 1996 and at monthly intervals at one site. Specimens were grouped in three size classes and their soft tissue was analyzed for As, Ca, Cd, Cr, Hg, Mn, Ni, Pb, Se, and Zn. Significant size effects were found for Ca, Cd, Cr, Cu, Ni and Zn. Spatial and seasonal variations in bioconcentration were significant for all metals. Spatial patterns in contamination that corresponded to known point sources of pollution or hydrology of the river were identified by principal component analysis. Seasonal variations can be attributed to the reproductive cycle of mussels and hydrological variability of the river. In comparison with values reported for zebra mussels in other contaminated sites in North America and Europe, levels of metal in the St. Lawrence River are low or intermediate. Our results show that when controlled for size and seasonal effects, zebra mussels represent a useful biomonitor for metal availability in the river and may offer an interesting alternative to native mussels and fish for such a role. Local contamination by some toxic metals is still a cause for concern in the St. Lawrence River.     

漳河上游流域沉积物中磷的空间分布特征及其影响因素

漳河上游地区众多的水利工程改变了流域水循环,同时也影响了河流泥沙和生源物质的循环过程。为揭示人类活动干扰下的沉积物中磷的赋存特征,采用改进后的连续化学萃取法分析了漳河上游沉积物中总磷(TP)和磷形态的空间分布特征及其影响因素。研究结果表明,漳河上游沉积物中的TP含量为405.94~899.98 mg/kg,低于我国其他主要河流,接近我国东部平原湖泊含量水平。漳河上游的TP富集指数(PEI)均值为1.15,表明漳河上游富营养化风险较高。可交换态磷(Ex-P)、铁锰螯合态磷(BD-P)、铁铝氧化态磷(NaOH-P)、钙结合态磷(HCl-P)分别占沉积物中TP含量的1.13%、33.96%、12.99%、35.05%。BD-P和HCl-P是沉积物中主要的磷形态,Ex-P的含量最低,NaOH-P的含量波动最大。漳河上游沉积物中,生物可利用磷(BAP)的含量约占TP含量的38.36%~52.04%,其中,清漳干流的BAP含量明显低于其他河段。清漳源头的水土流失及浊漳河的磷输入对漳河上游BAP含量的贡献较大。统计分析显示,漳河上游表层沉积物中,TP和磷形态的空间分布无显著差异,表明以水利工程建设为代表的强烈人类活动对漳河上游沉积物中磷的空间分布的影响不显著。相关性分析和冗余分析表明,沉积物中的NaOH-P含量与沉积物中黏土和粉土的占比有较高的相关性,BD-P和NaOH-P是控制沉积物中BAP构成的重要因素,Fe含量是沉积物中TP含量的主控因子。