海河流域中部表层沉积物中重金属分布特征及污染评价

为了解海河流域中部表层沉积物中重金属分布特征和污染现状,分别测定了17个采样点表层沉积物中Cr、Ni、Cu、Zn、As、Cd、Hg、Pb共8种重金属元素质量比,并采用相关性分析法、富集系数法、地累积指数法分析其同源性、污染来源及污染程度.结果 表明:海河流域中部表层沉积物中重金属质量比整体上较历史水平有所下降,8种重金...     

Nutrient concentrations in the surface sediments of Lake Chivero,Zimbabwe: A shallow,hypereutrophic, subtropical artificial lake

A lake‐wide survey in Lake Chivero, Zimbabwe, was performed to (i) examine the spatial distribution of three sediment grain sizes; (ii) determine their nutrient concentrations; and (iii) analyse the relationships between the measured surface sediment variables in the three sediment grain sizes. The results of this study indicated sand, silt and mud sediments occupied about 24, 22 and 54%, respectively, of the lake area. All the measured physicochemical variables varied significantly among the three sediment grain sizes (P < 0.05, anova ). High values for pH, dissolved oxygen and NO₃ were observed in the sand sediments, while water depth, electrical conductivity, soluble reactive phosphorus, NH₄, total phosphorus, total nitrogen and total organic carbon were observed in the mud sediments. In the silt sediments, most measured variables showed intermediate values. Intervariable correlation indicated varied correlation patterns among the three sediment grain sizes. Information generated in this study is essential for an accurate delineation of the spatial extent of nutrient and contaminant distribution in the sediment of Lake Chivero and will facilitate the ability of lake managers to derive a comprehensive nutrient budget of the lake as a means of establishing realistic target conditions for lake restoration.     

The occurrence of microcystin-LR in Lake Chivero, Zimbabwe

Lake Chivero is a eutrophic reservoir, initially constructed to supply drinking water to the City of Harare, Zimbabwe. Blooms of blue‐green algae have been a problem in the lake for many years and concern has been expressed about the toxins produced by Microcystis spp. The concentrations of the toxin, microcystin‐LR, produced in cultures of Microcystis aeruginosa from Lake Chivero, were investigated from March–April 2003. Microcystin‐LR was found in algal cells cultured from the lake water in concentrations ranging between 18.02 and 22.48 µg L^?1, with a mean concentration of 19.86 µg L^?1. These concentrations are the highest recorded to date for the lake, raising concerns about the possible effects of the toxin on the health of people who are drinking the water. Based on these study results, there is a need to control eutrophication, reducing algal blooms in order to prevent their potentially detrimental effects from blue‐green algal toxins produced under such conditions.     

Effects of heavy metal contamination from anthropogenic sources on Dasarahalli tank, India

This study examines the concentrations of various heavy metals, and their distribution in a hyper‐eutrophic urban Dasarahalli tank system, which is being polluted from industrial, domestic and sewage effluents. The concentration of iron (Fe), zinc (Zn), copper (Cu), nickel (Ni), chromium (Cr), lead (Pb) and cadmium (Cd) in water, plant (Alternanthera philoxeroides) and sediment samples was determined. The water‐soluble (bioavailable) fractions of heavy metals correlated positively with their total concentration, exhibiting the following sequence of bioavailability: Zn > Cd > Ni > Fe > Cu > Pb > Cr. A. philoxeroides exhibited a maximum bioaccumulation factor for cadmium (3913). The mean values of all types of collected samples were correlated with the corresponding mean values in a control tank (Vasanthapura tank). The sequence of the order of the concentrations of the metals in water, plant and sediment samples exhibiting higher values than those observed in the control tank was as follows: Cr > Ni > Pb > Cu > Fe > Zn, Cd > Cr > Fe ≈ Zn ≈ Cu ≈ Pb and Pb > Cu ≈ Cr > Zn ≈ Ni > Fe, respectively. The geoaccumulation indices of the heavy metals revealed that the tank is moderately contaminated. As A. philoxeroides is extensively used for human consumption and also as cattle fodder, there is a growing health risk that these metals could find their way into the human food chain.     

Baseline assessment of metals and hydrocarbons in the sediments of Lake Mulwala, Australia

An assessment of hydrocarbon and metal/metalloids (arsenic, cadmium, copper, lead, mercury, selenium, zinc) contamination in sediments from Lake Mulwala, Australia, was undertaken. The objectives of the study were: (i) to determine the extent of contamination in the lake sediments, compared to Australian and international sediment quality guidelines, and (ii) to attempt to identify the contaminant sources to the lake. With the exception of a few samples containing elevated levels of arsenic and/or mercury, the levels of all contaminants in the sediment samples taken from the lake were below the ‘lower trigger’ of the Australian Sediment Quality Guidelines that would warrant further investigation. High molecular weight hydrocarbons (up to 700 mg kg⁻¹) were found in most sediment samples. Non‐metric statistical analysis indicated that the contaminant distribution was different in different parts of the lake, with the lowest concentrations generally found at the influent to the lake. No definitive source(s) of contamination could be identified for either metalloids or hydrocarbons.     

洞庭湖流域沉积物重金属分布特征及其生态风险

以洞庭湖流域为研究对象,对比分析水体沉积物中7种重金属质量分数和分布特征,并对其来源和风险进行研究。结果显示:东洞庭湖中7种重金属质量分数在3个湖区中最高,入湖河流Cr、Pb质量分数在湘江较高,Ni、As、Cd质量分数在资水上游最高,Cu质量分数在资水下游最高,Zn质量分数在沅江下游最高,沉积物各元素空间分布差异大;地累积指数法显示,7种重金属污染情况排序依次为CdNiCrCuZnPbAs,东洞庭湖为湖区沉积物污染最严重区域,资水为入湖河流沉积物污染最严重区域,均达到严重污染程度;潜在生态风险指数法显示,单一元素污染危害程度依次为CdNiAsCuPbCrZn,全流域沉积物高风险因子Cd对生物影响最大,其在湖区中东洞庭湖最高,入湖河流中资水最高,流域整体处于高潜在生态风险水平;Pearson相关性分析和主成分分析显示,Cr、Ni、Cu、Pb和As可能属于自然来源,Zn可能来源于锌矿产的开采或矿产的岩石风化、侵蚀,而Cd可能来源于农药、化肥和生活污水,也可能来源于钢材制造、颜料、油漆等方面。     

南四湖表层底泥重金属空间分布及污染程度评价

测试南四湖湖区29个表层底泥中重金属Hg、Cd、Cr、Pb、Ni、Cu、Zn和类金属As的质量比,得到南四湖湖区重金属污染的空间分布特征。结合地质积累指数法和潜在生态风险指数法,对南四湖重金属污染程度进行评价。结果表明,南四湖已受到重金属元素的污染,属于中等程度污染湖泊,其中以As、Hg、Cd、Pb元素污染严重。除了As、Cd元素在下级湖表层底泥中的质量比略高外,其他重金属元素在上级湖的污染程度普遍比在下级湖的高;二级坝以北的昭阳湖湖区潜在生态危害最为严重,其次是南阳湖、微山湖、独山湖和二级坝以南的昭阳湖湖区。     

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.     

Contrasting sources and mobility of trace metals in recent sediments of western Lake Erie

Concentrations of the major and trace metals varied considerably in the western basin of Lake Erie, ranging from 0.9 to 25.3?mg/g for aluminum, from 2.9 to 36.5?mg/g for iron, from 6.4 to 74.8?mg/g for calcium, from 1.2 to 13.5?μg/g for cobalt, from 2.8 to 61.6?μg/g for copper, from 2.7 to 83.0?μg/g for lead, from 0.1 to 2.9?μg/g for cadmium, and from 7.1 to 127.3?μg/g for strontium. Distinct patterns of sediment metal variability allowed the identification of two major fluvial sources and some active in-lake biogeochemical processes. The inputs of Sr were largely from the Maumee River, the inputs of Cu, Pb, Cd, and Co were dominated by the Detroit River, and the inputs of Fe and Al were roughly evenly from the two rivers. The removal of Sr and Ca from the water column was mainly through coprecipitation with calcite. In contrast, the transfer of Cu, Pb, Cd, and Co was largely attributed to the removal of fine sediment particles from the Detroit River mouth and adjacent nearshore areas and the deposition of the metals scavenged by settling organic materials in the basin's central deeper areas. The mobility of the trace metals was different during the in-lake mass transfer, with Co being the most mobile and Cd being the least mobile. Furthermore, the trace metal mobility differences have decreased significantly during the past half-century due to a substantial increase in organic matter from eutrophication in the basin.     

青狮潭水库底泥重金属污染特征及潜在生态风险

广西桂林青狮潭水库由东湖和西湖两部分组成,为了研究青狮潭水库底泥重金属污染分布特征及潜在生态风险,测定了青狮潭水库不同位置底泥中5种重金属(As,Cd,Cr,Hg,Pb)的含量,并通过地累积指数法和潜在生态风险指数法评价了重金属的污染程度和潜在生态风险。结果表明:东湖底泥中As和Cd含量较西湖高,西湖Hg和Pb含量高于东湖;底泥中Cr主要来源于成土母质,船只通行是造成Pb污染的主要原因;东湖底泥中As和Cd可能主要来源于东江上游煤矿开采;西湖底泥中As,Cd,Hg与营养元素间存在显著相关性,其来源可能与周边农业活动和前期水库内网箱养鱼有关;根据地累积指数,重金属污染强度排序为Cd,As,Pb,Hg,Cr,Cd和As为主要污染元素;重金属潜在生态风险大小排序为Cd,Hg,As,Pb,Cr;东湖底泥重金属潜在生态风险强于西湖。     

Assessment of heavy metals in sediments and aquatic organisms in West Lake (Ho Tay), Hanoi, Vietnam

West Lake (Ho Tay) is the largest freshlake in Hanoi, Vietnam. It has a surface area of ≈ 500 ha and a total volume of >10⁷ m³, and is 1–3.5 m in depth. West Lake has been classified as needing protection because of its valuable freshwater genetic resources. Noting that it has been extensively affected by pollution, the objective of the present study was to examine the extent of heavy metal contamination of the sediments and commercially important biota in the lake. Heavy metal concentrations in the sediment from most of 24 samples in West Lake exceeded the Ontario Ministry of Environment Screening Level for chromium (Cr), copper (Cu), manganese (Mn), lead (Pb) and zinc (Zn) concentrations. Aquatic organisms from the lake also were found to be contaminated by heavy metals. The average Zn concentrations in snails and mussels tissues ranged between 174 and 415 µg g⁻¹, and the Pb concentrations between 3.5 and 5.2 µg g⁻¹. The Cu concentration in shrimp (52 µg g⁻¹) and snail (189 µg g⁻¹), and the Pb concentration in all fish species and shrimp from the lake (2.0–5.2 µg g⁻¹) exceeded the Food Standard Australia‐New Zealand (FSANZ) health standards for human consumption. The Cd concentration in Cyprinus carpio also exceeded the FSANZ standard. The implications of these study findings for the effective management of the food and ecological resources of West Lake are discussed.     

Heavy metals in sediments and uptake by burrowing mayflies in western Lake Erie basin

During the past two decades, burrowing Hexagenia mayflies have returned to the western basin of Lake Erie. Because of their importance as a prey resource for higher trophic levels and their extensive residence time in potentially contaminated sediment, Hexagenia may be a source of heavy metal transfer. To better understand the distribution and transfer of heavy metals in sediment and mayflies, sediment and mayfly nymphs were collected from 24 locations across the western basin of Lake Erie in May 2007. Following USEPA protocols, samples were analyzed for 16 elements using ICP-OES or ICP-MS. Metal concentrations in the sediments exceeded the Threshold Effect Level for at least one metal at all sample sites. Sediment heavy metal distribution profiles indicate metal concentrations are correlated with organic matter content, and the highest heavy metal concentrations were found in the central deeper region of the western basin where organic content in the sediments was greatest. Hexagenia were distributed throughout the western basin, with greatest density (1350/m²) within the Detroit River plume. The Cd and Zn levels in mayflies were on average approximately 4 and 2 times greater, respectively, than sediment levels, and the Cd concentrations in the sediments exceeded the Threshold Effect Level at 27 of 28 sites and exceeded the Probable Effect Level at 9 of 28 sites. Spatial representation of heavy metal concentrations in mayflies exhibited a similar pattern to the spatial distribution of heavy metals and organic matter in the sediments with higher concentrations of metals found in mayflies residing in the central deeper region of the western basin.     

石臼湖表层沉积物营养盐与重金属分布及污染评价

为揭示石臼湖表层沉积物营养盐和重金属的污染特征,于2018年2月采集表层沉积物,分析了石臼湖营养盐和重金属的含量、空间分布特征。结果表明:全湖有机质、TP和TN的平均质量比分别为30.25 mg/kg、585 mg/kg和776 mg/kg,TP为无污染风险级别,有机质和TN处于低污染风险级别;重金属Cr、Ni、Cu、Zn、As、Cd、Hg和Pb平均质量比分别为94.92 mg/kg、41.25 mg/kg、38.42 mg/kg、124.33 mg/kg、16.48 mg/kg、0.17 mg/kg、0.05 mg/kg和35.92 mg/kg,均超过了江苏省的土壤重金属背景值,Hg和Cd污染相对较重,全湖为中等危害等级;在空间分布上,东部区域的采样点8、9营养盐质量比较高,重金属污染较重。     

Sources and spatial distribution of lead (Pb) and cadmium (Cd) in saline soils and sediments of Mighan Playa (Iran)

Rapid industrialization has led to an extraordinary increase in environmental pollution in Arak, Iran. This study classified the distribution of iron (Fe), manganese (Mn), lead (Pb) and cadmium (Cd) in sediments and soils of Mighan Playa (Iran) and analysed the pollution sources using geostatistical methods. Samples were taken from 250 points and the data analysed by means of SPSS, GS+ and ArcGIS. The soils were moderate to considerable polluted with Pb and high to very high polluted with Cd. The comparison of the maps of EF for Pb and Cd with the maps of their total contents indicated they have two different distributions in the region. Lead was enriched near the pollution sources. However, Cd accumulated at the centre of Mighan Playa apart from the pollution sources, meaning Cd was highly mobile in the studied wet and salty soils.     

广州车陂涌底泥重金属污染及生态风险评价

合理处置重金属污染超标的底泥,是河道清淤工程的重点。以车陂涌清淤工程为例,通过原位测试、化学检验等,掌握河道清淤段不同位置底泥的污染特征。采用潜在生态危害指数法进行底泥污染潜在生态风险评价,得出河涌底泥低风险占31.71%、中等风险占29.27%、较高风险占2.44%、极高风险占36.59%,说明大多底泥需要处理。采用内梅罗综合污染指数法来评价底泥作为农用地土壤的适宜性,73.2%样点属于清洁,尚清洁、轻微污染各占9.8%,中度及严重污染共占7.2%,说明大部分底泥可用于农田。最后提出了该清淤工程应注意的问题,为车陂涌水环境治理提供科学依据。     

基于多种方法的太湖综合水质评价比较

水污染是太湖主要的水环境问题之一,准确合理地评价太湖水质状况对该地区水环境治理具有至关重要的作用。利用单因子水质标志指数法、综合水质标志指数法、改进的综合水质标志指数法及基于污染物权重的灰色关联分析法对2004—2013年典型断面的水质进行评价,水质单项指标评价表明太湖东部及东南部污染较严重且主要污染物为NH3-N,与该地区水体富营养化现状一致,综合水质评价表明近年来太湖水质呈逐年转好的趋势;对比研究结果表明,综合水质标志指数和改进的综合水质标志指数更接近太湖水质的真实情况,其中改进的综合水质标志指数法考虑了最差污染因子对综合水质的影响,克服了单项指标算术平均带来的误差,能真实反映流域的污染状况,为水环境治理工作提供更可靠的依据。     

Surface Deposition of Lead and Cadmium from the Atmosphere in the Detroit River—Lake St. Clair Region

The research reported here forms part of a large multidisciplinary study of four toxic contaminants — lead, cadmium, PCBs, and octachlorostyrene in the Essex region of southwestern Ontario. The purpose of this part of the project is to quantify the atmospheric loading of the metallic contaminants. A bulk precipitation sampler, wet-only precipitation sampler, and recording rain gauge were installed at an urban and rural site. Results from 2 years of data indicate that atmospheric loading of lead is 40–50 times that of cadmium in the city and 16–40 times that of cadmium in the rural areas. Lead loadings in the city were found to be 2–4 times higher than in the rural areas, while cadmium loadings appeared to be similar in both areas. Concentrations of the metals are higher in winter than in summer, but because of higher summer precipitation surface loadings are similar in both seasons. Preliminary statistical analysis indicates that concentrations of the metals are related to intensity and amount of precipitation but not usually to wind direction.     

黄河干流主要重金属污染特征及其与流量关系

黄河流域重金属污染是水资源利用的一个制约因素。本文利用黄河干流站点1992~1998年实测监测数据,对黄河干流重金属污染变化特征进行初步分析,并分析这些变化与流量之间的内在关系。研究表明,黄河干流重金属在空间和时间上变化比较复杂,没有很明显的规律性。从与流量关系看,非汛期随着流量增加而增加,汛期反而减少。其原因与泥沙(重金属的载体)浓度变化一致。     

鄱阳湖悬浮物重金属污染及潜在生态风险评价

为了分析鄱阳湖悬浮物重金属的潜在生态危害,实地采集水样分析了悬浮物重金属的含量及污染特征。根据分析成果,采用Hakanson潜在生态危害指数法评价了鄱阳湖悬浮物重金属污染程度。分析评价结果表明：鄱阳湖南湖区的悬浮物重金属潜在生态危害大于北湖区;具有潜在生态危害的主要重金属是Cd和Cu;鄱阳湖大部分区域已达中度以上危害程度,轻度危害水平区域只占1/8;悬浮物重金属的赋存含量不仅与其赋存方式有关,与元素本身也有关联性。