贵州煤矿区表层水-沉积物重金属分布特征及来源分析——以新寨河为例

为探索贵州煤矿区表层水-沉积物中重金属的分布特征及来源,科学制定环境保护与污染治理措施,以新寨河为研究对象,在11个样点共采集66个表层水体和沉积物样品,通过对Cd、Pb、Cr、Zn、Cu、As、Hg、Fe、Mn等9种重金属元素进行分析,揭示其在新寨河的空间分布特征。同时,利用多指数法开展了有毒重金属元素污染状况评价,通过相关性分析和主成分分析解析了重金属的来源。结果表明,新寨河流域表层水体中,Fe、Mn点位超标率达100%。表层水中重金属元素的平均含量排序为Fe＞Mn＞Zn＞Cu＞Cr＞As＞Cd＞Pb＞Hg,而沉积物中重金属元素的平均含量排序则是Fe＞Mn＞Zn＞Cr＞Cu＞As＞Pb＞Cd＞Hg,表明新寨河表层水体和沉积物中重金属元素的空间分布存在一定差异。各重金属元素的内梅罗综合污染指数介于0.59~1.13之间,表明新寨河表层水体中重金属的污染程度达到轻微污染水平。单种重金属元素的潜在生态危害系数计算结果显示,90.91%和9.09%的沉积物样点分别被归类为轻微风险和中等风险。所有样点沉积物的潜在生态危害指数介于14.57~120.55之间(均值为72.08),表明新寨河沉积物的潜在生态风险较低。Cu、As在多个样点存在污染现象,需予以重点监控管理。新寨河流域重金属的来源可分为三大类:Cd、Pb、Cr、Zn、Cu为第一类,对应地表径流源;As、Fe、Mn为第二类,对应煤矿开采源;Hg为第三类,对应复合源。     

湘江(衡阳段)河流沉积物中重金属潜在生态风险评价

对湘江（衡阳段）10个断面18个采样点的表层沉积物重金属（Cd、Hg、Pb、As、Cr、Zn、Cu）进行监测和分析，采用Lars Hanson潜在生态危害指数法对各种重金属的生态风险进行评价。结果表明，湘江（衡阳段）表层沉积物中各重金属潜在生态危害系数大小排序为：Cd〉Hg〉Pb〉As〉Cu〉Zn〉Cr。多种重金属的综合潜在生态风险指数RI为913．4，表明湘江（衡阳段）沉积物重金属污染属于很强的生态危害。     

湘江长沙段沉积物重金属污染状况及潜在生态风险评价

根据重金属环境化学行为的特点，应用沉积学原理，对湘江长沙段5个代表性断面10个采样点的表层沉积物中重金属（Hg、CA、As、Pb、Cu、Cr、Zn）进行监测和分析，采用Lars Hakanson潜在生态危害指数法对各种重金属的生态风险进行了评价。结果表明：按当地最高背景值为参比值计算，湘江长沙段表层沉积物中各种重金属潜在生态危害系数大小排序为Cd〉Hg〉As〉Pb〉Cu〉Cr〉Zn，多种重金属的潜在生态风险综合指数为560．8，表明湘江长沙段沉积物重金属污染属于强生态危害。     

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。     

南京市某垃圾填埋场重金属污染现状调查

对南京市某垃圾填埋场的垃圾、土壤、植物、炉渣等样品中Cu、Pb、Cr、Zn、Cd、Hg、As、Sb、Mn重金属含量进行分析。结果表明，垃圾填埋场的填埋土中Cu、Zn、As3种重金属含量分别高出自然土壤背景值86％、250％，300％。潜在生态危害指数法评价的污染状况为：Cd、As〉Hg〉Cu〉Pb〉Cr、Zn；Cd和As的毒性贡献较大，存在极高的潜在生态风险。     

治理后的太湖无锡区域底质中重金属污染现状及生态风险评价

以2005年以后太湖无锡区域底质为研究对象，分析了太湖底泥中重金属的含量分布及富集状况，采用地积累指数法和潜在生态危害指数法对重金属的生态危害进行评价。结果表明：太湖无锡区域底质受重金属轻度污染，含量高于全国水系沉积物平均值；地积累指数法显示太湖无锡区域底质中重金属污染排序为Cu=As〉Pb〉Zn〉Cr〉Cd〉Hg；金属对太湖无锡区域底质构成的潜在生态危害由强到弱为Hg〉Cu〉As〉Cd〉Pb〉Cr〉Zn；从区域上看，2种评价方法均表明底质中重金属危害程度为宜兴沿岸区〉梅梁湖〉五里湖〉贡湖无锡水域。     

珠江口黄茅海表层海水和沉积物中重金属的分布及评价

根据2014年4月对珠江口黄茅海海域表层海水和沉积物中重金属分布的调查监测,采用单因子指数法、内梅罗指数法和生态危害指数法对其重金属污染水平进行评价。结果显示:该海域表层海水中部分站位的Pb、Cu、Zn和Hg超出第一类海水水质标准,内梅罗指数评价表明其整体处于轻污染水平。表层沉积物中部分站位的Hg、As和Cu超出第一类海洋沉积物质量标准,内梅罗指数评价表明其整体处于重污染水平,生态危害指数评价表明其整体可能面临中度风险,Hg为主要风险因子。表层海水中Pb、Cu、Zn具有同源性,表层沉积物中Pb、As、Zn和Cu具有同源性。     

内蒙古畜禽养殖场周边土壤重金属污染特征及评价

于2015年5—8月采集内蒙古自治区东部、中部和西部地区32个畜禽养殖场周边共160个土壤样品,分析8种重金属含量。通过单项污染指数法和内梅罗综合污染指数法评价畜禽养殖场周边土壤重金属的污染程度,主成分分析重金属污染的成因和来源。结果表明,除Hg和As外,Cd、Pb、Cr、Cu、Zn和Ni 6种重金属的平均值均高于内蒙古自治区土壤背景值,其中Cd是背景值的2. 14倍。单项污染指数评价表明,重金属Cd在东部畜禽养殖场周边土壤中呈中度污染,在中部和西部地区畜禽养殖场周边土壤中呈轻度污染。不同重金属元素平均污染程度为:Cd Pb Cr(Ni) Zn Cu As Hg。内梅罗综合污染指数评价表明,东部地区畜禽养殖场周边土壤污染最严重,为中度污染,中部和西部地区畜禽养殖场周边土壤均为轻度污染。不同地区畜禽养殖场周边土壤重金属内梅罗综合污染指数大小顺序为:东部地区(2. 27)西部地区(1. 52)中部地区(1. 35)。主成分分析结果显示,内蒙古不同地区畜禽养殖场周边土壤不同重金属的来源存在差异,其中Pb、Cr、Cu、Zn和Ni主要来源于畜禽粪便和冲洗禽舍等污水的不当排放; Hg主要来源于自然源。     

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...     

银叶真藓(Bryum argenteum)监测黔滇高速公路重金属污染的研究

通过采集G60高速公路贵阳—昆明段自然分布的银叶真藓(Bryum argenteum),监测其中Zn、Cd、Cu、Cr和Pb的含量,并采用污染因子和主成分分析方法研究重金属污染程度及来源。结果表明:研究路段银叶真藓中的重金属含量由高到低依次为Zn Cu Cr Pb Cd,Zn和Cu质量比平均值分别为1 060 mg/kg和102 mg/kg,明显高于对照点。主成分分析表明,重金属Zn、Cu、Pb和Cd可能来源于交通污染,而Cr来源于其他污染源。污染因子分析表明,重金属Zn污染最严重,Cu总体属于重度污染,Cr和Cd属于中度污染,Pb总体污染较低。     

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。     

长江南京段近岸沉积物和土壤中重金属分布特征分析

通过测定沉积物和土壤中Cd、Pb、Cr、Zn、Cu、Ni 6种重金属元素的平均含量,计算其富集因子,分析长江南京段近岸沉积物和土壤中重金属的空间分布特征,结果表明,几种重金属在沉积物中的富集次序为:CdPbCr1NiCuZn,在土壤中为:CdZnCu1CrPbNi,除Zn和Cu外,其他几种金属在沉积物中的富集程度高于土壤,同时Cd的含量超过土壤环境质量三级标准。以Cd和Pb为例分析了重金属含量与沉积物粒级之间的关系,回归分析显示,Cd、Pb的含量与颗粒物的粒级呈显著的相关性,与细颗粒物的含量有密切关系,细颗粒携带的重金属,在长江水力分选作用下到达下游,成为沉积物中重金属的主要来源。     

Contamination assessment of arsenic and heavy metals in a typical abandoned estuary wetland—a case study of the Yellow River Delta Natural Reserve

Coastal and estuarine areas are often polluted by heavy metals that result from industrial production and agricultural activities. In this study, we investigated the concentration trait and vertical pattern of trace elements, such as As, Cd, Ni, Zn, Pb, Cu, and Cr, and the relationship between those trace elements and the soil properties in coastal wetlands using 28 profiles that were surveyed across the Diaokouhe Nature Reserve (DKHNR). The goal of this study is to investigate profile distribution characteristics of heavy metals in different wetland types and their variations with the soil depth to assess heavy metal pollution using pollution indices and to identify the pollution sources using multivariate analysis and sediment quality guidelines. Principal component analysis, cluster analysis, and pollution level indices were applied to evaluate the contamination conditions due to wetland degradation. The findings indicated that the concentration of trace elements decreased with the soil depth, while Cd increases with soil depth. The As concentrations in reed swamps and Suaeda heteroptera surface layers were slightly higher than those in other land use types. All six heavy metals, i.e., Ni, Cu, As, Zn, Cr, and Pb, were strongly associated with PC1 (positive loading) and could reflect the contribution of natural geological sources of metals into the coastal sediments. PC2 is highly associated with Cd and could represent anthropogenic sources of metal pollution. Most of the heavy metals exhibited significant positive correlations with total concentrations; however, no significant correlations were observed between them and the soil salt and soil organic carbon. Soil organic carbon exhibited a positive linear relationship with Cu, Pb, and Zn in the first soil layer (0–20 cm); As, Cr, Cu, Ni, Pb, and Zn in the second layer (20–40 cm); and As, Cr, Cu, Ni, Pb, and Zn in the third layer (40–60 cm). Soil organic carbon exhibited only a negative correlation with Cd (P?I _geo values), which averaged less than 0 in the three soil layers, this finding indicates that the soils have remained unpolluted by these heavy metals. The mean concentrations of these trace elements were lower than Class I criteria. The degradation wetland restoration suggestions have also been provided in such a way as to restore the reserved flow path of the Yellow River. The results that are associated with trace element contamination would be helpful in providing scientific directions to restore wetlands across the world.     

Groundwater environmental capacity and its evaluation index

At present, anthropogenic contribution of heavy metals far exceeds natural input in some aquatic sediment, but the proportions are difficult to differentiate due to the changes in sediment characters. In this paper, the metal (Al, Fe, K, Mg, Ca, Cr, Cu, Ni, and Zn) concentrations, grain size, and total organic carbon (TOC) content in the surface and core sediments of Nansihu Lake Catchment (the open lake and six inflow rivers) were determined. The chemical speciations of the metals (Al, Fe, Cr, Cu, Ni, and Zn) in the surface sediments were also analyzed. Approaches of factor analysis, normalized enrichment factor (EF) and the new non-residual fractions enrichment factor (K_NRF) were used to differentiate the sources of the metals in the sediments, from detrital clastic debris or anthropogenic input, and to quantify the anthropogenic contamination. The results indicate that natural processes were more dominant in concentrating the metals in the surface and core sediments of the open lake. High concentration of Ca and deficiency of other metals in the upper layers of the sediment core were attributed to the input of carbonate minerals in the catchment with increasing human activities since 1980s. High TOC content magnified the deficiency of the metals. Nevertheless, the EF and K_NRF both reveal moderate to significant anthropogenic contamination of Cr, Cu, Ni, and Zn in the surface sediments of Laoyun River and the estuary and Cr in the surface sediments of Baima River. The proportion of non-residual fractions (acid soluble, reducible, and oxidizable fractions) of Cr, Cu, Ni, and Zn in the contaminated sediments increased to 37–99% from the background levels less than 30%.     

Metal Pollution Assessment of Sediment and Water in the River Hindon, India

The metal pollution in water and sediment of the River Hindon in western Uttar Pradesh (India) was assessed for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. The metal concentrations in water showed wide temporal variation compared with bed sediment because of variability in water discharge and variations in suspended solid loadings. Metal concentrations in bed sediments provided a better evaluation of the degree and the extent of contamination in the aquatic environment, Santagarh and Atali being the most polluted sites of the river. The ratio of heavy metals to conservative elements (Fe, Al, etc.) may reveal the geochemical imbalances due to the elevated metal concentrations normally attributed to anthropogenic sources. Metal/Al ratios for the bed sediments of the river Hindon were used to determine the relative mobility and general trend of relative mobility occurred Fe > Mn > Zn > Cr > Ni > Pb > Cu > Cd.     

Assessment of heavy metals in sediments from a typical catchment of the Yangtze River, China

An intensive investigation was conducted to study the accumulation, speciation, and distribution of various heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in sediments from the Yangtze River catchment of Wuhan, China. The potential ecological risks posed by these heavy metals also were estimated. The median concentrations of most heavy metals (As, Cd, Cr, Cu, Ni, Pb, and Zn) were higher than the background values of soils in Wuhan and were beyond the threshold effect level (TEL), implying heavy metal contamination of the sediments. Carbonate-bound Cd and exchangeable Cd, both of which had high bioavailability, were 40.2% and 30.5% of the total for Cd, respectively, demonstrating that Cd poses a high ecological risk in the sediments. The coefficients of the relationship among Pb, Hg, and Cu were greater than 0.797 using correlation analysis, indicating the highly positive correlation among these three elements. Besides, total organic carbon content played an important role in determining the behaviors of heavy metals in sediments. Principal component analysis was used to study the distribution and potential origin of heavy metals. The result suggested three principal components controlling their variability in sediments, which accounted for 36.72% (factor 1: Hg, Cu, and Pb), 28.69% (factor 2: Cr, Zn, and Ni), and 19.45% (factor 3: As and Cd) of the total variance. Overall, 75% of the studied sediment samples afforded relatively low potential ecological risk despite the fact that generally higher concentrations of heavy metals relative to TEL were detected in the sediments.     

Distribution and accumulation of heavy metals in the sediments of Akkaya Dam,Nigde, Turkey

Twenty-one surface sediment samples were collected from Akkaya Dam. Heavy metal concentrations (Mo, Cu, Pb, Zn, Ni, Co, Mn, Fe, Cr, As, V and Cd), grain size, organic carbon and carbonate contents were studied in order to assess the extent of environmental pollution and to discuss the origin of these contaminants in sediments of dam. The sediments in the study area are mostly very fine sands. However, mud was observed in the northeast of the dam. Sediment pollution assessment was carried out using enrichment factor. The calculation of enrichment factors showed that Mo is depleted by 1.0 whereas Cu, Pb, Zn, Ni, Co, Mn, As, V, Cr and Cd are enriched by 3, 5.4, 7, 2.7, 2.2, 3.4, 42.3, 2.1, 1.8 and 7.2, respectively. Relatively high concentrations heavy metals occurred in north (textile industry area) and east (Karasu River) due to enrichment controlled by anthropogenic wastes. The results of correlation analysis show low–medium positive and negative correlations among metals, grain size, carbonate contents and organic carbon and indicate that heavy metals in sediments of the Akkaya Dam have different anthropogenic sources.     

Assessment of heavy metal contamination in Candarli Gulf sediment, Eastern Aegean Sea

Concentrations of selected heavy metals (Fe, Mn, Ni, Cu, Zn, Pb, Hg, Cr, Al, and As) in surface sediments from 18 stations in the Candarli Gulf were studied in order to understand current metal contamination due to urbanization and economic development in Candarli region, Turkey. The sediment samples were collected by box corer in Candarli Gulf in 2009 to assess heavy metal pollution. Heavy metal concentrations in surface sediment varied from 1.62% to 3.60% for Fe, 0.38?C2.53% for Al, 173?C1,423 for Mn, 8?C100 for Ni, 3?C46 for Cu, 55?C119 for Zn, 16?C138 for Pb, 0.2?C6.3 for Hg, 16?C71 for Cr, and 11?C37 mg kg^???1 for As. This study showed that the concentrations of Mn, Ni, Zn, Pb, Hg, and Cr in the surface sediment layers were elevated when compared with the subsurface layers. Both metal enrichment and contamination factors show that Hg, Zn, and Pb contamination exists in the entire study area and contamination of other metals is also present in some locations depending on the sources.     

The impact of an industrial complex on freshly deposited sediments, Chener Rahdar river case study, Shiraz, Iran

Concentrations of elements (As, Co, Cu, Ni, Mo, Pb, V, and Zn) are studied in the sediments of two adjacent stretches of Chenar Rahdar river. The first stretch (S1) is influenced by urban and arable land wastewater, and the second (S2) is mainly loaded with industrial effluents. The average abundance order of heavy metals content in S1 sediments is Ni > V > Zn > Cu > Co > As > Pb > Mo and in S2 sediments is Ni > Zn > V > Cu > Mo > Pb > Co > As. The maximum average concentration for these heavy metals (except for As) occurs in the S2 sediments. The contamination factor (CF) base of background in S1 for eight analyzed elements is moderate. The CF for Cu, Zn, and Pb in S2 sediments is considerable. The highest CF in S1 and S2 sediments is observed for Mo (CF = 10.95 and 12.41) and indicates very high contamination. The application of modified degree of contamination values (mC_d) indicates low and high degree of contamination (1.89–4.15) in S1 and S2, respectively. Calculated enrichment factors (EF) reveal enrichment of Mo and As in S1 and Zn, Cu, Mo, and Pb in S2 compared to the average abundances of background level. The maximum EF for Mo is 7.61 (significant enrichment), while Pb, Zn, and Cu with maximum EF between 2 and 5 indicate moderate contamination. Principal component analysis (PCA) shows distinctly different elemental associations in S1 and S2 sediments. The strong association of Zn, Co, Ni, Sc, Cu, Al and Fe in S1 suggests a similar source. The results of PCA for Zn, Pb, Mo and Cu in S2 (componente2) indicate that these metals are influenced by anthropogenic activity. Also, high loading heavy metals with OC (0.97) indicate that organic carbon plays a significant role in the distribution and sorption of these heavy metals in the sediments. Factor analysis indicates that As and Mo behave differently in sediment samples.