Heavy metals pollution in water,suspended matter and surface sediment in typical mountainous urban river:A case study in Qingshui Stream in Chongqing,China

Based on a detailed environmental investigation of the whole Qingshui Stream catchments,samples of water and surface sediments were collected at 15 different places from the upper to the lower reaches of Qingshui Stream,and samples of suspended matter were obtained by filtrating the water samples. The concentrations of heavy metals (Cd,Cu and Zn) were measured in filtered water,suspended matter,and surface sediment by ICP-AES. The results show that the concentrations of the three heavy metals in filtered water are 0.18,6.6 and 17.67 μg/L,lower than that of the Fresh Water Quality Criteria (US EPA) and those of the plain urban rivers,but the contents of Cd,Cu and Zn are much higher than the mean values of rivers in the world and the background value in Jialing River basin. The heavy metals concentrations in the suspended matter from Qingshui Stream are 2.08,438.14 and 1 348.05 mg/kg,much higher than the corresponding background values of soils in Chongqing city. The heavy metals concentrations in the surface sediment from Qingshui Stream are 0.84,189.75 and 838.23 mg/kg,and the values of index of geoaccumulation Igeo of Cd,Cu and Zn show that their pollution degrees are moderate. The heavy metals exist in three transferable forms such as water,suspended matter and surface sediment in Qingshui Stream. The heavy metals concentrations in water are the lowest,and those in the suspended matter are the highest,so the ecological risk in suspended matter is the highest. The distribution tendencies of three metals in water,suspended matter and surface sediment in main riverbed are different.

Distribution Pattern of Heavy Metals in the Surface Sediments of the Jiaozhou Bay

Grain size analysis and chemical analysis of heavy metals are made for 312 surface samples of the Jiaozhou Bay. Nineteen samples of the waste water taken from the sewage discharge outlets along the eastern coast of the bay are also analyzed for heavy metals. Results show that heavy metals are richer in the east and poorer in the west of the bay. Sedimentary dynamic studies reveal that the distribution of heavy metals in the surface sediments of the Jiaozhou Bay is under the control of hydrodynamics.

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 July 2012.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.

HEAVY METAL POLLUTION IN SURFACE SEDIMENTS COLLECTED FROM DRAINAGES RECEIVING DIFFERENT ANTHROPOGENIC SOURCES FROM PENINSULAR MALAYSIA

Surface drainage sediments were collected, between January and April in 2005, from 6 sampling sites in Peninsular Malaysia suspected to have received different anthropogenic sources. These drainages included sites near a petrochemical plant, an electronic factory, a metal factory and 2 townships in addition to a relatively unpolluted site (a reference site). Based on the aqua-regia method, the metal concentrations for all the sampling sites except for the agricultural site (reference site) at Sg. Benut were between 60.92-1 019 μg/g dry weight for copper (Cu), 65.32-1 266.6μg/g dry weight for plumbum (Pb), 1.46-15.93 μg/g dry weight for cadmium (Cd), 330.10-484.14 μg/g dry weight for zinc (Zn) and 47.03-120.90 μg/g dry weight for nickel (Ni). All of these ranges were significantly (p< 0.05) higher than those (Cu: 8.77 μg/g; Pb: 57.42 μg/g; Cd: 0.96 μg/g; Zn: 68.21 μg/g; and Ni: 17.87 μg/g) of the reference site at Sg. Benut that only received agricultural disposal. The concentrations for the 5 metals from all the sites (except for the reference site) were higher than the Sediment Quality Values for Hong Kong by Chapman et al (1999) for the 5 metals. Based on the sequential extraction technique, 3 geochemical fractions [easily, freely leachable and exchangeable (EFLE), acid-reducible and oxidisable-organic] were also useful in identifying these polluted sites. The elevated metal concentrations found in the sediments might be related to point sources of industrial effluent and urban waste. Hence, the results emphasized the necessity for the treatment of effluents into this drainage area. As part of the effort to control illegal discharges and dumping into drainages, public awareness should be enhanced.

Correlations between Geo-Chemical Speciation of Heavy Metals (Cu, Zn, Pb, Cd and Ni) in Surface Sediments and Their Concentrations in Giant Mudskipper (Periophthalmodon schlosseri) Collected from the West Coast of Peninsular Malaysia

Surface sediments and giant mudskipper (Periophthalmodon schlosseri) were collected in August and September 2008 and in March and June 2010 from six sampling sites in the west coast of Peninsular Malaysia to assess heavy metals accumulation in the giant mudskipper. Sequential extraction technique was used to fractionate the sediments into four different geo-chemical fractions;easily, freely or leachable and exchangeable (EFLE), acid reducible, oxidizable organic and resistant fractions. Heavy metals concentrations (Cu, Zn, Pb, Cd and Ni) in the surface sediments and giant mudskipper were determined by using air acetylene flame atomic absorption spectrophotometer (AAS) Perkin Elmer Analyst 800. The results of Pearson’s correlation analyses showed that metal concentrations in the tissues of P. schlosseri were significantly correlated (p p < 0.05), correlations were observed between Cu in P. schlosseri and Cu in the sediment (oxidisable-organic, resistant and total Cu), Zn in P. schlosseri and Zn in the sediment (EFLE and total Zn), Pb in P. schlosseri and Pb in the sediment (with all the four fractions of Pb), Cd and Ni in P. schlosseri and Cd and Ni in the sediment (with all fractions of Cd and Ni except acid-reducible Cd and Ni) which might suggest the use of P. schlosseri as a biomonitoring agent for heavy metals pollution in the west coast of Peninsular Malaysia.

Ecological Risk of Heavy Metals in Sediment Around Techeng Island Special Marine Reserves in Zhanjiang Bay

The concentrations of five metals(Cu, Pb, Zn, Cd and Hg) were measured in sediments obtained before and after the establishment of Techeng Island Special Marine Reserves(TCISMR) in Zhanjiang Bay to evaluate the ecological risk of heavy metals. The results showed that average values of potential ecological risk indexes of heavy metals at all stations increased slightly from 32.09 to 30.54 after establishment of TCISMR. Optimal semivariance simulation showed that the contents of five heavy metals have strong spatial correlations in August 2010(before), while this correlations weakened in April 2013(after establishment of TCISMR), suggesting that the main sources of heavy metals changed. The Hakanson Risk Index(HRI) values in Donghai levee, central and southern parts of Zhanjiang harbor were high up to 60.13 and 46.46, respectively. And Zhanjiang Bay Channel, the areas around special marine reserves, the artificial reef areas and mangrove areas at south of Techeng Island are the areas with low ecological risk and high ecological value, which should be treated as the prior ecological protection areas. Our study provided a priority control pattern of heavy metal pollution in TCISMR, which greatly benefits the sustainable development and resource protection in Zhanjiang Bay.

Heavy Metal Concentrations in Pores and Surface Waters during the Emptying of a Small Reservoir

The impact of reservoir emptying on the concentrations of dissolved heavy metals (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in pore and surface waters was studied in the Aar Reservoir, a small reservoir in central Germany, during and after the emptying process. This study was conducted to observe binding changes within pore waters as well as the input of dissolved heavy metals in waters of the Aar Creek, what becomes possible when the reservoirs water table is removed and lake sediments become exposed. In pore waters, no clear shifting tendencies between dissolved and sorbed heavy metal fractions could be found after the completed sediment exposure. These relatively low dynamics in pore waters can be explained by the fine texture of the lake sediments, which are characterized by a high water holding capacity, what led to high remaining water contents and therefore slowed down the redox changes. A few days after the completed emptying, a general increase of dissolved heavy metal concentrations occurred in running waters of the Aar Creek as a result of pore water drainage. Here, element specific differences in mobilization and transportation abilities were found, what can be reconstructed by the ratio of dissolved heavy metals in pore and surface waters.

Investigation on Fe,Mn,Zn,Cu,Pb and Cd fractions in the natural surface coating samples and surficial sediments in the Songhua River,China

Natural surface coating samples （NSCSs） from the surface of shingles and surficial sediments （SSs） in the Songhua River, China were employed to investigate the relationship between NSCSs and SSs in fractions of heavy metals （Fe, Mn, Zn, Cu, Pb, and Cd） using the modified sequential extraction procedure （MSEP）. The results show that the differences between NSCSs and SSs in Fe fi＇actions were insignificant and Fe was dominantly present as residual phase （76.22% for NSCSs and 80.88% for SSs） and Fe-oxides phase （20.33% for NSCSs and 16.15% for SSs）. Significant variation of Mn distribution patterns between NSCSs and SSs was observed with Mn in NSCSs mainly present in Mn-oxides phase （48.27%） and that in SSs present as residual phase （45.44%）. Zn, Cu, Pb and Cd were found dominantly in residual fractions （〉48%）, and next in solid oxides/hydroxides for Zn, Pb and Cd and in easily oxidizable solids/compounds form for Cu, respectively. The heavy metal distribution patterns implied that Fe/Mn oxides both in NSCSs and SSs were more important sinks for binding and adsorption of Zn, Pb and Cd than organic matter （OM）, and inversely, higher affinity of Cu to OM than Fe/Mn oxides in NSCSs and SSs was obtained. Meanwhile, it was found that the distributions of heavy metals in NSCSs and SSs were similar to each other and the pseudo-total concentrations of Zn, Cu, Pb and Cd in NSCSs were greater than those in SSs, highlighting the more importance for NSCSs than SSs in controlling behaviours of heavy metals in aquatic environments.

霍邱县城湖泊沉积物重金属污染特征、潜在生态风险及来源

为了解霍邱县城西湖和城东湖表层沉积物重金属的污染特征、空间分布、潜在来源和生态风险,对城西湖和城东湖表层沉积物重金属(As、Cd、Cr、Cu、Hg、Ni、Pb和Zn)含量进行了分析,采用地累积指数法、污染负荷指数法、潜在生态危害指数法和沉积物质量基准法对重金属污染程度及潜在生态危害进行了评价,并利用相关性分析、聚类分析及主成分解析了重金属来源。结果表明,除城东湖的Cd、Hg、Pb和城西湖的Hg外,其余元素均值超过背景值,重金属含量存在显著的空间变异性,大致呈北向南递减趋势。地累积指数表明城西湖沉积物中Ni和Zn处于未受污染中度污染状态,污染负荷指数显示城西湖为中度污染状态,城西湖和城东湖处于轻度生态风险状态。重金属溯源分析结果显示城西湖和城东湖沉积物中Cr、Zn、Ni和Cu主要来源成土母质、矿产开采和水产养殖,As、Pb、Hg和Cd主要来源于农业污染和生活污水。研究结果可为城西湖和城东湖重金属污染防治提供科学依据。

江苏徐圩港区表层沉积物重金属污染评价及来源分析

为科学评估江苏徐圩港区建设开发对周边生态环境的影响,2022年9月测定了徐圩港区表层沉积物10种常见重金属含量,运用单因子污染指数法、潜在生态风险指数法、地质累积指数法、相关性分析和主成分分析,对该港区进行重金属污染评价及来源分析。调查区域沉积物中所有站位重金属含量均符合第一类海洋沉积物标准,单因子污染指数法显示有个别站位属于中等污染,综合污染指数结果显示,有4个站位属于轻微污染,5个站位属于中等污染。潜在生态风险指数显示沉积物重金属潜在生态风险由高到低为Cd>As>Cu>Ni>Pb>Co>Zn>V>Cr>Mn,综合生态风险指数结果显示仅有1个站位属于严重污染。地质累积指数显示沉积物重金属污染程度由高到低为Cd>As>Zn>Cu>Ni>Mn>Co>Pb>V>Cr,总体污染情况较轻。Cr,V,Co,Pb,Ni和Cu之间具有极显著相关性,Cd与其他重金属元素均无强相关性。PC1(V,Cr,Mn,Co,Ni,Cu,Pb)主要为水产养殖、工业生产、航运交通和自然源的混合源;PC2(Cd)主要为机械制造等工业活动来源;PC3(As,Zn)主要为农业和生活污染等人为来源。Cd是徐圩港区潜在污染重金属,生态风险指数较高,因此应加强对徐圩港区相关重金属的监测,查清重金属污染的主要来源,为生态环境保护和管理提供基础资料。

黄河三角洲北部湿地沉积物重金属污染风险评价及来源分析

以黄河三角洲北部湿地39个表层沉积物样品为研究对象,测定Cu、Pb、Zn、Cr、Ni、Cd、As、Hg的含量,对其进行重金属污染风险评价及来源分析。结果表明:8种重金属元素在表层沉积物中平均含量由高到低顺序为:Cr>Zn>Ni>Pb>Cu>As>Cd>Hg,除As外其含量均低于山东省土壤背景值;沉积物以砂质粉砂为主,重金属元素的空间分布特征相似,可能受到“粒度效应”的影响;基于地累积指数法和潜在生态危害指数法,揭示了Cd、Hg为研究区主要污染物和重要的潜在生态危害因子;相关分析和因子分析表明,Cu、Pb、Zn、Cr、As、Hg可能来源于成土母质、工业活动以及油田开采,Ni、Cd可能来源于农业活动、水产养殖以及油田开采;聚类分析表明,可进一步把Cr单独分为一类;通过因子探测分析发现,黏土含量、TOC和含水率对潜在生态危害指数(RI值)解释力较大,表明其对RI值的影响较大;通过交互作用探测分析可知,任意两个影响因子交互作用后结果为双因子增强或非线性增强,表明复杂的环境加剧了湿地的潜在生态危害。

2010-2020年伶仃洋表层沉积物重金属含量及潜在生态风险变化

珠江口是中国重金属污染最严重的河口之一,为了解该河口区近十余年来的重金属污染变化状况,分别于2010和2020年在污染物最易聚集的伶仃洋海域开展了表层沉积物调查取样工作,并使用ICP-MS方法测试了所有样本的V、Cr、Co、Ni、Cu、Zn、Cd、Pb等重金属含量。结果显示,2020年所取沉积物中Cd、Cr、Cu、Zn和Pb的平均含量都比2010年样本的含量显著降低,V和Ni的变化甚微,Co的含量则明显上升。富集系数法和潜在生态危害指数法的评价结果也反映出2020年沉积物中Cd、Cu、Pb、Zn以及Cr的富集程度及潜在生态危害总体上较10年前都有不同程度的缓解,但仍有超过50%的样本中Cd呈现中度—显著富集。V和Ni在2个时期的沉积物中均为轻微富集或基本无富集,但2020年属轻微富集的比例相比2010年有所增加。Co的富集程度及潜在生态危害较2010年加剧,但尚属轻微级。空间上看,伶仃洋4大口门水道,尤其是洪奇沥和蕉门水道,仍为珠江口重金属污染的重灾区,其中,Cd依然是富集程度最高、受人为影响最大且潜在生态风险最强的重金属,其次是Cu和Pb。

钦州湾沉积物中重金属的多元统计分析:空间关系、生态风险和来源识别

海湾是海洋和陆地相互作用和人类活动最强烈的区域,沉积物中重金属的含量和分布都受到人类活动的影响。为了探究钦州湾沉积物中重金属的含量水平、污染程度和可能来源,本研究分析了钦州湾表层沉积物中Cu、Pb、Zn、Cd、Cr、Hg和As的含量及空间分布,采用地质累计指数(Igeo)和潜在生态风险指数(PERI)定量分析了重金属的污染程度和生态风险,并利用自组织映射(SOM)和正定矩阵因子分解法(PMF)模型评估了重金属的可能来源。结果表明:钦州湾表层沉积物重金属中Zn的平均含量最高,Hg平均含量最低;除个别站位的Pb含量符合海洋沉积物质量第二类标准外,其他重金属含量均符合海洋沉积物质量第一类标准;Igeo结果表明钦州湾表层沉积物主要的污染元素为Pb、Hg和Cu;PERI结果表明Hg是钦州湾表层沉积物主要的生态风险元素。SOM和PMF模型结果表明钦州湾表层沉积物重金属主要受自然来源、农业活动、工业生产活动的共同影响,各来源的相对贡献率分别为39.65%、29.15%和31.20%。

江苏中部潮间带表层沉积物重金属分布、来源及污染评价

基于2015年江苏中部潮间带89个站位表层沉积物的测试分析结果和以往资料,探讨了Cu、Pb、Zn、Cr、Cd、As和Hg 7种重金属元素的含量、空间分布特征和相关性,并采用沉积物质量基准法、地累积指数法和富集系数对该区重金属状况进行了系统评价。结果表明,表层沉积物中重金属元素含量相差较大,平均含量由高至低依次为Cr>Zn>Cu>Pb>As>Cd>Hg,空间分布不均匀,高值区呈点状或片状分布。沉积物质量符合中国海洋沉积物质量第一类标准,所有站位的重金属含量均低于可能效应水平(PEL),综合潜在生态风险为低风险。元素相关性分析、地累积指数、富集系数和R型因子分析结果表明:Cu、Pb和Zn元素主要来自于地壳物质或自然风化作用,未污染、未富集;Cr元素含量受自然和人类活动共同作用的影响,部分站位轻度污染和轻度富集;Cd、As和Hg元素含量受人类活动影响较大,较为富集,污染程度较重。

北部湾表层沉积物中重金属与放射性元素/核素的分布、风险、源解析与环境研究启示

本研究对北部湾表层沉积物中的重金属(Hg、Cr、Zn、As、Cd、Ni、Cu、Pb)和放射性核素(238 U、232 Th、210 Pb、239+240 Pu)进行全面分析,以评估其环境风险并考察其作为环境指示物的有效性。结果表明,除了局部地区的Cr浓度超出《海洋沉积物质量》(GB 18668-2002)中的第一类指标外,其他重金属浓度均低于第一类指标。放射性核素的环境风险评估显示238 U和232 Th属于第二级(安全级别),而210 Pb和239+240 Pu尚缺乏评估标准。研究发现部分重金属和放射性元素/核素呈现出“T”型分布,指向多样化的污染源和传输机制。结果显示放射性元素/核素在海洋环境监测和管理中具有独特的源相示踪潜力,海洋放射性研究可作为交叉学科为海洋环境保护和污染综合治理研究提供新的启示。

刘公岛周边海域表层沉积物重金属分布特征及潜在生态风险评价

本文根据刘公岛周边海域16站位沉积物样品监测数据,采用单因子污染评价法和潜在生态危害指数法,对刘公岛周边海域表层沉积物重金属质量状况进行了评价。结果表明:研究区表层沉积物中Hg、Cd、Cu、Pb、Zn含量高于我国浅海沉积物,发生一定程度富集,整体呈西北高、东南低的分布态势;第一类质量标准面积占比约55%,第二类质量标准占比约45%,无第三类质量标准海域;整体为中等生态风险区,单项生态风险指数由高至低排序为Hg>Cd>As>Cu>Pb>Co>Ni>Zn>Cr,其中Hg潜在生态危害相对较大。

黄骅近岸海域表层沉积物重金属污染特征与生态风险评价

以2020年4月在黄骅近岸海域进行的表层沉积物调查为依据,采用污染指数法、改进污染指数法、潜在生态风险指数法结合地理信息系统(ArcGIS)空间差值分析等方法,对研究区域表层沉积物的重金属元素污染情况及生态风险进行研究。结果表明:研究区域表层沉积物中重金属平均含量由大到小依次为Zn(74.95 mg/kg)>Cr(56.40 mg/kg)>Cu(21.11 mg/kg)>Pb(17.11 mg/kg)>Cd(0.24 mg/kg)>Hg(0.08 mg/kg)。重金属污染程度由高到低依次为Cd>Hg>Zn>Cr>Cu>Pb,其中Cu、Pb、Cr、Zn污染指数相对较小,总体呈现出轻度-中度污染水平,Hg、Cd污染指数相对较高,总体呈现出中度-重度污染水平。研究区域表层沉积物中重金属整体呈现无污染-中度污染水平。研究区域表层沉积物重金属潜在生态风险由高到低依次为Hg>Cd>Cu>Pb>Zn>Cr,其中Cu、Pb、Cr、Zn生态风险较低,Hg和Cd生态风险较高,是造成研究区域表层沉积物潜在生态风险的主要元素。研究区域表层沉积物重金属来源较为复杂。沉积物中Cu、Pb、Cr主要为自然来源,黄骅周边工业及港口活动是黄骅近岸海域重金属Hg、Cd和Zn污染的主要来源,也是导致研究区域内部分区域综合潜在生态风险较高的主要因素。

巢湖北岸烔炀河流域池塘沉积物中重金属污染特征

在巢湖北岸烔炀河流域,选择不同利用类型的池塘钻取了沉积物柱状样,分析了沉积物重金属元素浓度,并剖析了重金属在水平、垂向上的分布特征和污染程度。结果表明,池塘表层沉积物中Cr、As、Hg、Cd、Cu、Pb、Ni、Zn浓度分别为56.5~91.0、6.4~10.1、0.06~0.11、0.10~0.25、18.07~28.77、11.58~17.60、15.94~19.0、42.26~68.07 mg/kg;垂向上随着沉积物深度增加,重金属浓度总体呈下降趋势。烔炀镇老镇区池塘(S1)表层沉积物中重金属浓度高于其他池塘。烔炀河流域池塘沉积物中重金属Cr、Hg、Cu、Zn、As等5种重金属元素具有同源性,受成土母质影响,而Ni、Pb、Cd 3种重金属受人类活动影响;池塘表层沉积物重金属综合潜在生态风险指数处于轻微生态风险。

常德市柳叶湖表层沉积物重金属元素分布特征及潜在生态风险评价

柳叶湖表层沉积物中重金属的状况对洞庭湖流域生态环境具有重要影响。对该区域内31个采样点表层沉积物中重金属的含量及形态进行监测和分析,同时采用潜在生态风险指数法和健康风险评价模型进行风险评价。结果表明:(1)重金属平均值均高于洞庭湖水系水体沉积物重金属元素背景值。参考《土壤环境质量标准农用地土壤污染风险管控标准(试行)》(GB 15618—2018),Cd可能存在污染风险。(2)Cd、Cr、Pb、Cu、Zn、Ni来源相似,Mn有单独的来源,As有多个来源。(2)表层沉积物中As、Cr、Cu、Zn、Ni主要以残渣态为主,Cd和Mn主要是以弱酸可提取态和可还原态为主,Pb主要以可还原态为主。(3)Cd的单项潜在生态风险指数为57.0,属于中等风险,其他7种重金属均属于轻微风险。8种重金属的综合潜在生态风险指数为100.8,属于轻微风险。(4)成人、儿童的致癌、非致癌总风险处于可接受范围,且儿童的致癌、非致癌总风险指数均高于成人。As的致癌风险指数大于Cd;Zn的非致癌风险指数最低,而Cr最高。