Distribution and pollution assessment of trace metals in seawater and sediment in Laizhou Bay

Selected trace metals(Pb, Cd, Cu, Hg) and arsenic in seawater and surface sediments of Laizhou Bay were determined, to evaluate their spatial distribution, pollution risk and potential ecological risk. Concentrations of the elements were 0.56–2.07, 0.14–0.38, 12.70–18.40, 0.014–0.094, and 1.13–2.37 μg/L in the seawater and 8.94–32.2, 0.18–0.67, 4.51–30.5, 0.006–0.058, and 5.75–15.3 mg/kg in sediments for Pb, Cd, Cu, Hg and As, respectively. High concentrations of the trace metals and arsenic in seawater and surface sediments were generally observed near the river estuary. The pollution risk result of the elements showed that Cu was the prominent trace metal pollutant in seawater, followed by Hg, Pb, Cd and As. The metal complex pollution index in seawater was at a medium level. The most important trace metal pollutant in sediments was Cd, followed by As, Cu, Pb, and Hg. Our pollution assessment suggests that trace metal pollution in Laizhou Bay sediments was at a low level. The potential ecological risk was also low in surface sediment.     

Distribution and source of main contaminants in surface sediments of tidal flats in the Northern Shandong Province

Twenty-nine samples of surface sediments from tidal flats in the Northern Shandong Province were collected for grain size, heavy metal(Hg, Cu, Pb, Zn, Cd, and Cr), and oil pollution analyses. The geoaccumulation index(Igeo) and factor analysis were introduced to evaluate sediment quality and source of contaminants. The mean concentrations of Hg, Cu, Pb, Zn, Cd, Cr, and oil in the surface sediments in the study area are 0.033, 17.756, 19.121, 55.700, 0.291, 59.563, and 14.213 μg g-1, respectively. The heavy metal contamination in the old delta lobe is slightly higher than that in the abandoned delta lobe; however, the opposite was observed for oil pollution. The Igeo results revealed that the overall quality of the surface sediments in the study area is in good condition. The heavy metal pollution levels show a descending order: Cd Hg Cr Cu Zn Pb, Cd being the main pollutant. The contamination level for in the study area is relatively lower than those for China's other tidal flats. Heavy metals are mainly derived from natural sources of rock weathering and erosion, partly influenced by industrial and agricultural discharge. However, oil pollution is mainly from runoff input, motorized fishing boat sewage, and oil exploitation.     

Assessment of heavy metals in sediment in a heavily polluted urban river in the Chaohu Basin,China

The Nanfei River(Anhui Province,China) is a severely polluted urban river that flows into Chaohu Lake.In the present study,sediments were collected from the river and analyzed for their heavy metal contents.Multivariate statistics and the fuzzy comprehensive assessment method were used to determine the sources of pollution,the current pollution status,and spatial and temporal variations in heavy metal pollution in sediments.The concentrations of arsenic(As),cadmium(Cd),chromium(Cr),copper(Cu),mercury(Hg),nickel(Ni),lead(Pb),and zinc(Zn) in sediments ranged from 5.67–113,0.08–40.2,41.6–524,15.5–460,0.03–4.84,13.5–180,18.8–250,and 47.9–1 996 mg/kg,and the average concentrations of each metal were 1.7,38.7,1.8,5.5,18.8,1.3,2.5,and 11.1 times greater than the background values,respectively.Multivariate statistical analysis demonstrated that Hg,Cu,Cr,Cd,and Ni may have originated from industrial activities,whereas As and Pb came from agricultural activities.The fuzzy comprehensive assessment method,based on the fuzzy mathematics theory,was used to obtain a detailed assessment of the sediment quality in the Nanfei River watershed.The results indicated that the pollution was moderate in the downstream tributaries of the Nianbu and Dianbu Rivers,but was severe in the main channel of the Nanfei River and in the upstream tributaries of the Sili and Banqiao Rivers.Therefore,sediments in the Nanfei River watershed are heavily polluted and urgent measures should be taken to remedy the status.     

210Pb chronology and trace metal geochemistry in the intertidal sediment of Qinjiang River estuary, China

Historical records of metal inputs were studied by using a sediment core collected from a sand-rich mudflat in the Qinjiang River estuary, China. 210Pb chronology was used to reconstruct the fluxes of Hg, Cu, Pb, Zn, Cd, Cr and As to the core site during the last 86 years. Based on the constant initial concentration model, the sedimentation rates are 1.18 cm year-1 in the top 30 cm sandy layer and 0.92 cm year-1 in the muddy bottom layer. To compensate for grain-size and mineralogy effects on metal concentra-tions, aluminum was used as the normalizing element. The enrichment factors (EF) indicate that the natural inputs had prevailed up to the early 1980s. After this period, the intensity of human activities has resulted in continual increasing trend of metals towards the surface. Recent sediment samples from the Qinjiang River estuary are found moderately enriched by Cd (EF>1.5) and slightly enriched by other metals (EF<1.5). Considering that the drainage area of the Qinjiang River is mostly agricultural land, the increased Cd may be due to the usage of fertilizers and pesticides in agricultural activities and the combustion of fossil fuels.     

Evaluation on environmental quality for heavy metal elements of Xihe soil

According to ＂Environmental quality standard for soil＂ and using As, Cd, Cr, Cu, Hg, Ni, Pb, Zn elements as evaluation index, the author evaluated soil environmental quality in Xihe area of Shenyang. The results show that the soil in Xihe area is polluted rifely by heavy metal elements. The polluted areas are mainly distributed near the upstreams of Xihe River, Shenxin River and Shenliao irrigation canal. There exist large distinctions among the heavy metal elements to the pollution degree. Cd pollution area is the biggest and the most serious in pollution degree.     

Measurement and Scaling of Mercury on Soil and Air in a Historical Artisanal Gold Mining Area in Northeastern China

The Jiapigou gold mine area, located in the upper reaches of the Songhua River, was the first and largest artisanal gold mine once in China, and it used to be prominent in two marking years(1870 and 1974). Jiapigou area had a gold mining history of more than 190 years, which was first opened in 1820. Gold extraction with algamation was applied as the dominant method of excavation from 1940 to 2008, and a total of more than 100 t of gold were extracted from the mine using this method and it was estimated that 100–200 t Hg were released, thus causing severe mercury environmental pollution in the mining area. In the experimental campaigns of this study, in situ air and soil Hg concentrations and air-soil Hg fluxes were measured from April 2009 to December 2011. The results showed that in the study area the total gaseous mercury(TGM) concentration exhibited remarkable spatial and temporal distribution patterns, i.e. the TGM gradually decreased following the increase in distance to gold mining sites in space, and the values in spring, summer and autumn were elevated by 1–2 orders of magnitude in comparison with those in winter. Furthermore, at other sampling sites the total soil mercury(TSM) concentration in spring was higher than that in autumn, except for the contrary laws demonstrated at the Erdaogou mining site. However, in spring and winter the Hg flux between air and soil was under the control of different environmental factors, and the characteristics were clear and distinct. In spring the Hg flux between air and soil was directly under the control of solar irradiation, and the releasing process was predominant with a remarkable positive correlation to solar irradiation. Nevertheless, in winter the Hg fluxes were indirectly under the control of solar irradiation, which caused thermal inversion due to the thick snow cover. The depositing process was predominant and the correlations between Hg flux and air temperature was remarkably negative, and there was a positive correlation between Hg flux and solar irradiation.     

Source apportionment of heavy metals in soils around a coal gangue heap with the APCS-MLR and PMF receptor models in Chongqing,southwest China

This study studied the characteristics and source apportionment of heavy metal pollution in the agricultural soil surrounding a gangue coal heap in Chongqing, China by using absolute principal component scores-multiple linear regression(APCSMLR) model and positive matrix factorization(PMF)model. The applicability of the models was compared in the assessment of source apportionment. The results showed that the average contents of Cd, Hg,As, Pb, Cr, Cu, Ni, and Zn in the surface soil were 0.46, 0....     

Distribution and accumulation characteristics of heavy metals in sediments in southern sea area of Huludao City, China

The southern sea area of the Huludao City, Liaoning Province might be polluted by heavy metals because it is close to the Jinzhou Bay, one of the heaviest sea area polluted by heavy metals in China. The undisturbed modern sediment core can be used to analyze the accumulation and source of the pollutants using 137 Cs and 210 Pb ex . Thirty-five samples of surface sediment and two core sediments were collected from the southern sea area of Huludao City. The concentrations of copper (Cu), lead (Pb), chrome (Cr), zinc (Zn), arsenic (As) and mercury (Hg) in the surface sediments as well as Cu, Pb, Zn, Cr, 137 Cs and 210 Pb ex in the core sediments were determined to research the spatial distribution and accumulation characteristics, and to analyze the sources and the potential risks of heavy metals. The results show that the pollution levels of Zn and Hg are serious, and 26 stations are at moderate or heavy ecological risks. The concentrations of the heavy metals increase from east to west, as well as from open sea to offshore marine area. The concentrations of heavy metals are not high in the sediments adjacent to the Jinzhou Bay, and the influence caused by the seawater exchange with the Jinzhou Bay is little. The concentrations of the heavy metals in the core sediments show low-high-low characteristic, and it coincides with the pollution history of Huludao City. The atmospheric deposition of heavy metals from the Huludao Zinc Plant is likely to be the main source of pollution without direct discharge of wastewater. The high concentrations of heavy metals appear on the upper sediment of 20 cm. The shallow sediment with high heavy metal contents might be exposed to surface when it was disturbed by the ocean engineering and big storm surge, then cause risk to the safety of aquaculture and human healthy.     

Spatial Distribution and Ecological Risk Assessment of Heavy Metals in Surface Sediment of Songhua River,Northeast China

The Songhua River, one of the seven major rivers in China, locates in Northeast China with 1897 km long. This study aims to investigate the concentrations, distribution, source apportionment and ecological risk assessment of heavy metals including copper(Cu),zinc(Zn), cadmium(Cd), lead(Pb), nickel(Ni) and chromium(Cr) in main stream and tributaries of the Songhua River in Jilin Province, Northeast China. Surface sediment samples(0–15 cm) were collected from 39 sampling sites in the Songhua River in July2012. Concentrations of Cu, Zn, Cd, Pb, Ni and Cr were analyzed. The mean concentrations of heavy metals were(24.0 ± 9.2) mg/kg,(59.3 ± 18.0) mg/kg,(4.0 ± 2.1) mg/kg,(39.0 ± 27.9) mg/kg,(18.5 ± 8.6) mg/kg and(56.1 ± 17.6) mg/kg for Cu, Zn, Cd, Pb, Cr and Ni,respectively. The average contents of Cu, Cd, Pb, Cr and Ni were higher than their background values. Higher concentrations of heavy metals were found in the lower reaches with industrial enterprises and cities along the Songhua River. Zn, Pb and Ni might come from industrial sewage and mineral processing, while Cu and Cd were derived from electroplating wastewater and agricultural non-point source sewage. Cr originated from lithogenic sources. The concentrations of Cu, Zn and Cr were below the effect range low(ERL) at all sites, while Cd, Pb and Ni concentrations were detected ranging from ERL to the effect range median(ERM) at more than 15% of samples. Concentrations of Ni exceeded ERM in more than 50% of samples. The mean toxic units of heavy metals in the Songhua River decreased following the order: Cd(6.7) Pb(2.2) Ni(1.6) Cu(0.7) Cr(0.5) = Zn(0.5). Potential ecological risk index was found to be higher in middle and lower reaches of the Songhua River, where Cd could impose an extremely high ecological risk.     

Spatial Variation and Risk Assessment of Arsenic and Heavy Metals in Surface Water and Suspended Particulate Matter in Tail Reaches of the Yellow River,China

To determine the pollution levels and potential toxic risks of arsenic(As) and heavy metals(Cr, Ni, Cu, Zn, Pb and Cd) in water and suspended particulate matter(SPM) in tail reaches(including freshwater reach and low-salinity reach) of the Yellow River as the Flow-Sediment Regulation Project(FSRP) has been carried out for approximately 15 yr, the surface water and SPM were sampled at pre-flood(April) and post-flood seasons(October). Results showed that similar changes of As and metal levels in water and SPM were observed along the tail reaches at pre-flood or post-flood season. Compared to pre-flood season, the levels of As, Cu, Cr and Ni in freshwater reach and the concentrations of Cr and Ni in low-salinity reach rose greatly at post-flood season. The levels of As and metals in SPM of freshwater reach or low-salinity reach at pre-flood season were significantly higher than those at post-flood season(P < 0.01).The pollutions of As and metals in surface water of tail reaches at pre-flood or post-flood season were not serious. The SPM in freshwater reach at pre-flood season were polluted by Cd, As, Cr, Cu and Ni while those in low-salinity reach were polluted by Cd and Cr. The SPM in freshwater reach at post-flood season were polluted by Cd and Pb while those in low-salinity reach were polluted by Cd and Cr.Cd was identified as heavy metal of primary concern at both pre-flood and post-flood seasons. Combined with the existed data reported in present research, this study found that the toxic risk of As and metals in SPM of tail reaches at pre-flood season was higher than that at post-flood season, implying that the implementation of FSRP during flooding season, to a great extent, reduced the toxic risk of these elements. With the long-term implementation of FSRP, the pollution levels of As and metals(particularly for Cd) in SPM of tail reaches might be elevated and the potential toxic risk primarily produced by Cr, Ni and As might be increased if effective measures were not taken in future.     

RELATIONSHIPS BETWEEN FRACTIONATIONS OF Pb, Cd, Cu, Zn AND Ni AND SOIL PROPERTIES IN URBAN SOILS OF CHANGCHUN, CHINA

1IN T R O D U C T IO N With therapiddevelopment of urbanizatio,nurban land was exploitedand utilizetdoform differendtomains be- ing subjectto many potentialpollutionsourcessuch as vehicleemission, industrialactivitieasnd household garbage.Particularl, yur…     

烟台近岸海域表层沉积物重金属污染特征

采取烟台近岸海域150个海底表层沉积物样品进行Hg,Cu,Pb,Zn,Cd,Cr,As,Ni元素分析。结果显示,烟台市近岸海域重金属主要富集在芝罘湾(Cd,Cu)、龙口(As,Cr,Cu)及海阳东部(Ni,Pb)一带,而莱州、招远及牟平近岸海域重金属含量较低。单因子、内梅罗和潜在生态危害指数评价结果显示,研究区88%海域的沉积物达到一类标准,轻污染区主要分布在芝罘岛北部及龙口市西部,龙口、招远及烟台市近岸沉积物潜在风险中等。     

煤矸石堆附近耕作层土壤中重金属污染状况与评价——以鲁西南煤炭基地为例

通过对鲁西南煤炭基地若干混堆的煤矸石山周围耕作层土壤的实际调查及分析测试资料,研究了煤矸石堆附近耕作层土壤中重金属污染状况。结果表明,土壤局部已经受到Cd、Ni的污染,但未出现多金属复合污染状况。煤矸石堆附近土壤已经受到采矿等人类活动的影响,其中Cd,Hg的人为影响最大。从8种重金属元素含量随深度的变化曲线形态来看,Hg,Cd 2种元素与Cr,Ni,Cu,Zn,Pb,As 6种元素曲线形态显示差异性,Hg,Cd元素在土壤中赋存、迁移等应具特殊性,有待进一步研究。     

章丘区北部土壤重金属地球化学特征及潜在生态风险

以山东省济南市章丘区北部表层土壤中As等8种重金属元素为研究对象,利用多元统计进行重金属来源分析,采用污染负荷指数法及潜在生态危害指数法进行污染评价,结果表明:研究区表层土壤重金属元素含量低于济南市土壤背景值,Cd和Hg元素含量为强度变异,在表层土壤产生一定的富集;不同土地利用类型下重金属元素含量具有差异性。土壤中Cr,Cu,Ni和Zn来源于土壤母质,Cd和Pb元素来源于人类活动,As元素来源复杂。土壤综合污染以轻度污染为主,重金属元素污染程度大小为AsNiPbZnCrCuCdHg。综合潜在生态风险以轻微和中度为主,潜在生态风险强弱程度为HgCdAsCuPbNiCrZn,建议防范Hg和Cd元素污染及生态风险。     

山东烟台南部海岸带地区土壤重金属来源、空间分布及潜在风险评价

海岸带处于陆地和海洋的接合部,人类开发活动密集,环境影响因素日趋复杂。选取烟台南部海岸带为研究对象,系统采集686个表层土壤样品对As,Cd,Cr,Cu,Hg,Ni,Pb,Zn共8个重金属元素含量进行测量,采用多元统计法及地统计法分析了8个重金属元素的来源及分布特征。最后对烟台南部海岸带地区进行了潜在生态风险评价。研究结果表明烟台南部海岸带地区整体污染程度较轻,所有重金属元素含量平均值均未超过国家二级标准。其中Cr,Ni,Cu元素主要来源于成土母质;As,Pb为混合源;Cd,Zn主要来自于工业三废、农业生产。研究区整体处于中低生态风险水平,Cd,Hg元素高生态风险点数量较多,需优先治理。     

滨州海岸带土壤和海底沉积物重金属空间分布特征

通过对滨州近海海域海底沉积物测试数据及海岸带陆域土壤地球化学分析,对滨州海岸带陆域土壤和海底沉积物中7种重金属(Hg,Cd,Pb,Cu,Zn,Cr,Ni)的空间分布特征进行了研究,并绘制了各指标含量陆海联合分区图。分析结果表明,滨州市海岸带重金属元素含量基本上均低于国标规定的海洋一类沉积物的最高标准,仅有个别元素含量超过一级标准值,表明局部存在一定的重金属污染。从滨州海岸带重金属含量空间分布上来看,除Hg元素外,其余重金属元素含量呈现一定的规律,基本上陆域含量高于海域含量,且大部分元素都呈现出陆域城镇值高,郊区值低的态势。区内化工企业较发达,Ni,Cr属于中度变异区,Cd,Hg,Pb属于高度变异,受人为影响因素较大,考虑区内土壤及海底沉积物重金属富集主要来源于工业"三废"。     

Geochemical characteristics of heavy metals in riparian sediment pore water of Songhua River,Northeast China

This study reports the geochemical characteristics of zinc (Zn), copper (Cu), lead (Pb), nickel (Ni), mercury (Hg), iron (Fe), and manganese (Mn) in the riparian sediment pore water of the Songhua River, Northeast China. In total, 36 pore water samples and 18 surface water samples from three typical sections were collected and analyzed in June 2009. Cluster analysis of heavy metals was performed to analyze the pollution sources of the metals. Results showed that Hg concentrations in the pore water were greater than those in the surface water, indicating a potential ability of Hg release from riparian sediment system to river water. However, concentrations of Fe and Mn in the surface water were greater than those in the pore water, demonstrating that the microenvironments of riparian and riverbed sediment systems were quite different. Variations of Zn, Cu, Pb and Ni between the surface and the pore water were different in each section. Most metals had similar horizontal and profile distribution characteristics in the three sections except for Zn and Ni. Hg, Fe and Mn concentrations in the pore water increased gradually with the increase in horizontal distance from water body, in contrast to this, Cu decreased, and Pb presented a fluctuating trend. With the increase in depth, Pb and Fe, Cu and Mn showed the same trends, and Hg showed a variable trend. The above distribution characteristics could mainly be attributed to the properties and the interactions of metals, pH and oxidation-reduction conditions, and the complex pollution sources and hydrologic regime in history. The probable sources of metals include the historical and ongoing discharge of industrial wastewater, mining activities, sewage irrigation for agricultural production, and atmospheric deposition from coal-fired plants.     

资江河口区农田土壤重金属污染评价及来源分析

资江是洞庭湖的第二大支流，其中上游锑(Sb)矿采矿冶炼工业发达，给资江下游及洞庭湖区带来了严重的重金属污染风险。以资江河口区为研究区，采集了132个农田土壤样品及7个资江水样，综合采用多种污染评价方法、空间分析、多元统计分析方法对研究区重金属进行了污染评价及来源分析。结果表明，研究区农田土壤重金属平均质量分数表现为Zn>Cr>Ni>Pb>Cu>As>Sb>Cd，旱田土壤重金属平均质量分数除Pb外均高于水田。Sb、As、Cd为主要污染元素，Sb达到了中等污染和中等生态风险的程度，总体处于轻微-中等生态风险程度。资江水体Sb质量浓度较高，平均为10.51 μg/L。Sb主要来源于中上游的锑矿工业，受高锑质量浓度地表水灌溉、垃圾填埋场以及燃煤等人为活动的控制；Cd主要来源于农药化肥、生活垃圾和城镇废水等人为活动；Cr主要来源于成土母质，而Cu、Zn、As、Ni、Pb受成土母质和人为活动的双重控制。      

典型石漠化峰丛洼地土壤重金属的空间分异特征及其影响因素

研究石漠化峰丛洼地土壤重金属空间分异特征及其影响因素, 对推动区域土壤重金属污染防治、石漠化综合治理具有重要的指导意义和实践价值。以广西平果市典型石漠化峰丛洼地土壤为研究对象, 通过调查采样分析以及综合运用地统计学、地质累积指数、潜在生态危害指数和地理探测器等方法, 分析探讨土壤重金属的空间分异特征及其影响因素。结果表明, 研究区8种重金属元素的空间分布总体呈东北向西南降低的变化格局, 研究区东北部和东南部为重金属高值叠加区的集中分布区, Cr,Cd元素呈现中等的空间相关性, 其他6个重金属元素表现为强空间相关性;研究区受Cd,As,Cr,Cu,Zn等元素不同污染程度的影响, 且以Cd的影响尤为突出, 其地质累积指数和潜在生态危害指数分别高达1.34和107.73;pH、地层、Fe₂O₃、土地利用、P、CaO、Mn、到断层距离、石漠化程度是影响研究区土壤重金属空间分异的主要因子, 而且不同因子组对土壤重金属空间分异的交互作用以双因子增强型和非线性增强为主。因此认为不同因子对石漠化峰丛洼地土壤不同重金属元素空间分异特征的影响程度存在差异, Cd是石漠化峰丛洼地土壤污染程度和潜在生态危害程度最严重的重金属元素, 地层、Mn、CaO、岩性、到断层距离、P是影响Cd空间分异的关键因子。