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1.
太湖沉积物和湖岸土壤的污染元素特征及环境变化效应 总被引：38，自引：3，他引：38
太湖沉积物和湖岸土壤具有相似的物质组成，具有相同的物源，通过补给区的径流，营养元素和重金属元素随着土壤迁入湖泊，由于沉积物和土壤物化条件的不同，它们的营养元素和重金属含量有差异。土壤中氮，磷的总量和有效态均比沉积物中高，表明有一部分营养物质进入了水体；营养元素高的沉积物均靠近城镇，其原因为居民生活污水排放，土壤和沉积物中多数重金属元素尚未超过自然背景值，只有沉积物中Cd和Pb，土壤中的Cu,Cd和Hg超过，但沉积物中重金属元素大多比土壤中高，特别在北部沿岸沉积物中，重金属元素含量大大超过平均值，这种不正常的高值是由人类不合理的废水，废物敢排放引起。 相似文献
2.
The mobility, bioaccessibility and transfer pathways of metals and metalloids in estuarine sediments have been the focus of much detailed research. However, to date, few studies have examined the mineralogical siting of metals and metalloids in such sediments. This is despite the fact the mineralogy of sediments is an important factor that controls which and how much of a particular metal is released to pore waters and overlying water columns. This study reports on the mineralogical siting of metals in contaminated estuarine sediments, Hobart, Australia, and aims to evaluate the mobility of metals in the contaminated substrates. Mineralogical, mineral chemical and bulk chemical analyses demonstrate that the sediments contain very high levels of several metals and metalloids. The contaminated sediments have concentrations of zinc (Zn), lead (Pb), copper (Cu) and cadmium (Cd) ranging from 0.55 to 4.23 wt%, 0.16 to 0.70 wt%, 415 to 951 mg/kg and 23 to 300 mg/kg, respectively. Franklinite and lesser sphalerite are the main repositories of Zn, whereas much of the Pb and Cu is hosted by sulfides, organic matter and undetermined iron (Fe) oxides. While the release of contaminant loads from franklinite through dissolution is likely to be insignificant, even small releases of metals from the highly contaminated sediments can still cause the deterioration of local water quality. The contaminated sediments represent long-term sources of metal pollutants, particularly Zn, to local waters. This study demonstrates that mineralogical analyses are a vital tool to recognise the potential mobility of trace metals in estuarine environments. 相似文献
3.
Suspended and bed sediments collected from the entire region of the Godavari River basin were analyzed for Fe, Mn, Cr, Cu, Ni, and Zn. There are pronounced temporal and spatial variations in the heavy metal distributions. The concentrations of heavy metals in the suspended sediments are significantly higher than the bed sediments.Throughout the basin heavy metals are enriched in the finer fractions (<2 µm) of the bed sediments. The average heavymetal composition of the sediments is higher when compared to the average Indian river sediments. Heavy-metal concentration in the two shallow cores collected shows, to some extent, the influence of urbanization. When compared to the other tropical Indian rivers such as the Krishna, the Godavari appears to be a significant contributor of heavy metals to the Bay of Bengal. Considering the enormous sediment load of the Godavari River—170 million tons/yr, the heavy metal fluxes to the Bay of Bengal is very significant. Except for the Pranhita, other tributaries of the Godavari do not contribute significant loads of heavy metals. All the metals show high correlation among themselves and the correlation is more pronounced in suspended sediments than in the bed sediments. The heavy-metal distribution, fractionation, and its relationship with total suspended sediments and depth in various parts of the basin are discussed in detail. 相似文献
4.
《Applied Geochemistry》2002,17(7):923-933
The accumulation and storage of trace metals in coastal sediments is an environmental concern. It is, therefore, important to understand better how these metals are bound or released under different redox conditions. This study of Fe and trace metal fixation under continuously anoxic conditions in the bottom sediments and the lower water column of the Nordåsvannet fjord in western Norway contributes further to such understanding. It allows investigation of both an end member redox state and one important mechanism of Fe and trace metal accumulation in sediments, the pyritization of Fe and trace metals. Pyrite formation occurs both in the water column and in the sediments of the Nordåsvannet fjord and favours the fixing of Fe and trace metals in the bottom sediments of the fjord. Thus, these sediments act as a continuous sink for Fe and trace metals. The DOP, and the degrees of trace metal pyritization for Mo, Ni and Cr correlate with organic matter content. While it is generally thought that Fe is the factor limiting pyrite formation in anoxic environments, this study found that degrees of pyritization of Fe (DOP) are clearly below 100%, and the availability of metabolizable organic matter is limiting pyrite formation. This is an important finding, because it indicates that increased supply of organic and mineral matter by higher runoff from land would further enhance the fixation of these metals in the fjord sediments, as would higher organic matter availability from increased productivity due to higher nutrient supply. The metals stored in the bottom sediments could be released into the biogeochemical cycle if redox conditions were to change from anoxic to suboxic or oxic. The fjord would then become a source rather than a sink for these metals. 相似文献
5.
选择太仓市郊区河流沉积物为研究对象,开展了重金属污染现状及评价研究。研究表明,相对于地壳或页岩平均值,沉积物中大部分重金属呈现不同程度的富集;地质累积指数和富集因子分析表明,位于城镇附近的采样点受到污染,且主要污染因子为Cr、Cu、Cd、Pb、Zn等。结果显示,沉积物Zn含量高达1770mg／kg,是农用污泥Zn使用容许最高值500mg／kg的3倍多,沉积物由于Zn、Cr、Cu等的严重污染不能用作施用污泥;利用重金属与Fe之间的相关特征结果显示,城镇工业、生活污水的排放是沉积物重金属污染的主要因素。 相似文献
6.
Geographical variations of trace elements in sediments of the major rivers in eastern China 总被引：10，自引：0，他引：10
A total of 26 geographically and hydrologically diverse sediment samples were collected from 12 major rivers in eastern China.
The <63-μm fraction of the sediments was analysed for both total concentrations of Cu, Zn, Pb and Cd, and their associations
with various geochemical phases. The geographical variations of sediment-bound trace metals can be related to the bedrock
types and weathering processes in the corresponding river basins. The rivers in southern China had notably higher concentrations
of trace metals in sediments because of abundant non-ferrous mineral deposits and stronger weathering process in the region.
A large proportion of trace metals in these sediments was associated with iron and manganese oxides and organic matter. Relative
low levels of trace metals were found in river sediments in northern China, and a significant proportion of the metals was
bound to organic matter, carbonates, and the residual fraction. The sediments in the Yellow River, originating from special
loess, had the lowest concentrations of trace metals. Most of the trace metals were associated with the carbonates and residual
phases.
Received: 24 March 2000 · Accepted: 11 July 2000 相似文献
7.
Bed sediments were collected from the entire region of the Ganges basin and some parts of the Brahmaputra. In addition, selected
stations were sampled for suspended sediments as well. The samples were analysed for a number of heavy metals (Fe, Mn, Ni,
Cr, Cu, and Zn) by the thin-film energy dispersive X-ray fluorescence technique. There are pronounced temporal and spatial
variations in the heavy metals distributions. Suspended sediments are 5–10 times richer than the bed sediments. None of the
tributaries contribute significant heavy metal load, but around urban areas in Yamuna (tributary of Ganges), very high levels
due to the distribution from the drainage network are observed. Compared to the Brahmaputra, the distribution and fractionation
of heavy metals in the Ganges sediments are more erratic and highly variable. All the metals considered show high correlation
among themselves. Given the high flux of suspended sediments from the Himalayan rivers (nearly 20% of the global flux), the
worldwide budget for heavy metal transport may need to be suitably revised. 相似文献
8.
On their way from the Rhine estuary into the North Sea and Dutch Wadden Sea, Rhine sediments “lose” large portions of their
original heavy metal concentrations. Until now these losses were explained by a mobilization process, solubilization — the
decomposition products of organic matter form soluble organometallic complexes with the metals of the sediment.
Our investigations of the sediments of the Elbe clearly indicate that a mixing process, whereby highly polluted Elbe sediments
mix with relatively non-polluted North Sea sediments, rather than solubilization, is the cause of the dilution of heavy metals
in the sediments of the Elbe estuary. Because of the similarity of the Elbe data with those from the Rhine River, we propose
that a mixing process is also effective in the Rhine estuary and adjacent North Sea areas.
The mechanism by which heavy metals are “diluted” is important to the marine ecosystem. In the mixing process proposed in
this paper, the heavy metals fixed to the suspected material are trapped in bottom sediments of the marine environment, whereas
solubilization would increase the concentration of heavy metals in the sea water and thus they would be more available for
uptake by aquatic organisms. 相似文献
9.
因重金属难以被生物降解,易形成毒害环境因子,沉积物中的重金属污染演变是工业化以来全球共同面临的生态环境问题。为揭示福建三都澳地区人类活动与重金属沉积的关系,对采集自三都澳海域的6根岩心柱进行了系统的粒度分析、210Pb测年以及重金属元素测试。研究结果表明：（1）近百年来,三都澳海域沉积物重金属含量呈现显著增加趋势,顶部比底部增加1.01~2.8倍,并表现出3个明显演变阶段：1900-1950年,沉积物中的重金属含量相对稳定;1950-2000年,重金属含量开始缓慢增加;2000年以来,远岸区重金属含量急剧增加。这种变化趋势与人口、经济发展密切相关。（2）三都澳近岸区沉积物重金属含量总体大于远岸区,自2000年以来,近岸区和远岸区沉积物重金属含量的演变趋势呈现差异性,表现为近岸区重金属含量有所降低,远岸区重金属含量急剧升高,这种时空差异与沉积物粒度变化及地区产业分布有密切关系。（3）重金属对三都澳海洋生态环境影响较大,在湾内渔业养殖强度越来越高的背景之下,应对近期以来湾内重金属含量的快速升高给予足够重视,提高保护和修复治理力度,避免海洋生态破坏。 相似文献
10.
11.
P. Szefer G. P. Glasby J. Geldon R. M. Renner E. Björn J. Snell W. Frech J. Warzocha 《Environmental Geology》2009,57(4):847-862
Analysis of 59 surface sediment samples from the Polish exclusive economic zone (EEZ) shows that Szczecin Lagoon sediments
are the most polluted by heavy metals and that the degree of heavy-metal pollution decreases substantially on passing from
the Szczecin Lagoon to the Pomeranian Bay and the inner shelf area and then on passing to the Bornholm Deep and Słupsk Furrow.
Heavy-metal pollution in the sediments of the western part of the Polish EEZ therefore appears to follow the dispersion of
the Oder River. Fluffy material from the Oder estuary appears to be the main source of heavy metals in the muddy sediments
of the Bornholm Deep. The formation of sulphides is therefore not the principal factor controlling the enrichment of heavy
metals in the sediments of this anoxic basin, although it may be responsible for the uptake of Mo, Sb and As. Two main factors
control the distribution of the rare earth elements (REE) in sediments of the Polish EEZ: the input of Fe-organic colloids
from rivers and the presence of detrital material in the sediments. 相似文献
12.
武汉市墨水湖沉积物重金属污染特征与防治对策 总被引：8，自引：2，他引：8
武汉市墨水湖重金属污染严重,其污染特征在我国城市湖泊中具代表性。在对墨水湖不同湖区沉积物中重金属污染物空间分布特征进行分析的基础上,应用地积累指数法探讨不同重金属元素含量随深度变化的规律和原因,并对墨水湖沉积物中重金属的污染程度进行评价表明:墨水湖沉积物中重金属元素锌和汞污染最为严重,污染程度由高到低依次为:Zn>Hg>Cu>C r>Pb>A s;从整个湖区来看,分布有排污口的周边湖区污染严重,湖心污染程度较低;沉积物中主要重金属元素含量随深度增加而降低,其变化规律主要受污染状况的影响,沉积物颗粒粒径的变化和早期成岩作用的影响不大。为了改善墨水湖水质条件和重金属污染严重的现状,必须在截污、疏浚和引水工程等基本治理措施保护下,重建和恢复沉水植物系统,才能从根本上改善湖泊水质。 相似文献
13.
Samples of stream sediments were collected along two streams adjacent to a sanitary landfill. One of the streams drained the landfill directly. In addition, control of background samples were also analyzed from a stream not affected by the landfill. All samples were analyzed for Ag, Zn, Cu, Cd, and Pb content using atomic adsorption techniques. The pH of the three streams were monitored since pH differences in the streams may affect the quantities of metals adsorbed or precipitated on the sediments. The comparison between the content of Ag, Zn, and Cu in the sediments of the two study streams and the same metals in the control sediments indicated the landfill emitted these metals into the two adjacent streams. However, since the Cd and Pb contents in the sediments of both streams were similar to that of the control stream sediments, these metals may not be emitted into the two study streams from the landfill and they represent only background quantities. The comparisons of each metal in the sediments of each stream were made by the use of a metal trend chart, the individual calculated mean metal content values, and by the statistical two sample t-test. No decreasing trends of the quantities of Ag, Zn, or Cu as a function of increasing distance from the landfill was present in the sediments along the stream that drained the landfill directly. These sediments might have been affected by stream action and became mixed with other sediments downstream. 相似文献
14.
S. Miko G. Koch S. Mesić M. Šparica-Miko M. Šparica R. Čepelak A. Bačani P. Vreča T. Dolenec S. Bergant 《Environmental Geology》2008,55(3):517-537
Due to their balneotherapeutic features, the organic-rich sediments in Makirina Cove are an important source of healing mud.
An environmental geochemistry approach using normalization techniques was applied to evaluate the anthropogenic contribution
of trace metals to sediments used as healing mud. Sediment geochemistry was found to be associated with land-use change and
storm events, as well as with proximity of a road with heavy traffic in the summer months. Local valley topography preferentially
channels lithogenic and pollutant transport to the cove. Concentrations and distribution of trace metals indicate lithogenic
(Ni, Cr, Co) and anthropogenic (Pb, Cu, Zn and Se) contributions to the sediments. The calculation of enrichment factors indicates
a moderate (EFs between 2–3.5) input of anthropogenic Cu and Pb in surficial sediments to a depth of 10 cm. Patients using
the Makirina Cove sediments as healing mud could be to some extent exposed to enhanced uptake of metals from anthropogenic
sources via dermal contact. 相似文献
15.
Analysis of sediment samples collected from the Coeur d'Alene River in northern Idaho, USA, indicates that the main stem and
the south fork of the river are contaminated with heavy metals (Cd, Pb, Mn, and Zn) from the local mining operations. Laboratory
experiments indicate that these metals in the sediments can be leached and reach saturation concentrations in water in a relatively
short period of time. The rate of leaching of heavy metals with distilled water appeared to follow first-order kinetics. The
saturation concentrations of Mn and Zn in water reached ppm levels from the leaching process. Cadmium and Pb are much less
soluble relative to Zn in the sediments. The high concentrations of heavy metals in the sediments are a source of contamination
that should be considered for the water quality management planning of the Coeur d'Alene River-Lake system. 相似文献
16.
As evidenced by catastrophic cadmium and mercury poisonings in japan, heavy metals belong to the most toxic environmental pollutants. Through the investigation of sediments, the extent, distribution and provenance of heavy metal contamination in rivers and lakes can be determined and traced. Eight heavy metals from the clay fraction of sediments from major rivers within the Federal Republic of Germany were determined by means of atomic adsorption spectrometry. Heavy metals especially known for their high toxicity are enriched most: mercury, lead and zinc by a factor of 10; cadmium by a factor of 50, as compared with the natural background of these elements. A mobilisation of heavy metals from the suspended load and from the sediments, as to be observed in rivers approaching the marine enviromment, could endanger marine organisms, thus negatively influencing the acquatic food chain. With a further increase of heavy metal pollution, a threat to the drinking water supplied by rivers and lakes cannot be excluded. 相似文献
17.
Incorporation of metalliferous sediments from historic mining into river floodplains 总被引：1，自引：0，他引：1
Stephen B. Bradley B.Sc.Ph.s. 《GeoJournal》1989,19(1):5-14
Rivers and their floodplains are dynamic systems, sediments are continually added to floodplain surfaces, while erosion and scour may remove sediments to be added to floodplains further downstream. When mining sediments were introduced into some catchments in Britain as ore deposits were exploited, river channels and floodplains were grossly polluted with metals. The legacy of this uncontrolled release of contaminants is apparent still, and contemporary channel deposits are enriched in metals. While the floodplains acted as a buffer to the dispersal of metals straight through the catchment, metals are still being released hundreds of years later as the floodplains are eroded and this secondary pollution of the river is a long-term problem.By studying a range of mining catchments, the effects of key variables on heavy metal dispersal in the fluvial environment can be assessed. As no single catchment displays the whole array of possible situations, a mosaic of case studies from several areas provides a good representation of potential conditions. 相似文献
18.
A field study was conducted to clarify the effect of rhizosphere processes on the accumulation and partitioning of heavy metals
(Pb, Zn, Cu, Cr, Cd and Ni) in mangrove sediments. Metals were fractionated by a sequential extraction procedure into three
chemically distinct fractions: water soluble, exchangeable and carbonate bound (B1), Fe–Mn oxide bound (B2), and organic and
sulfide bound (B3). Results indicate that rhizosphere processes tend to increase the metal concentrations in the rhizosphere
sediments. However, plant uptake may result in the decrease of the metal concentrations in the rhizosphere sediments when
the metal concentrations are relatively low in the bulk sediments. Compared with the bulk sediments, the rhizosphere sediments
have low concentrations of heavy metals in the B1 and B2 fractions and high concentrations in the B3 fraction. Either an increase
or decrease in the residual fraction of heavy metals in the rhizosphere sediments may appear, depending on whether the formation
of the refractory metal-organic compounds or the activation of the residual fractions dominates. Results also indicate that
mangrove plants absorb and store non-essential metals in the perennial tissues, thus reducing the export of non-essential
metals via leaf litter transport. Mangrove plants are excellent candidates for phytostabilization of heavy metals in intertidal
substrates. 相似文献
19.
吉林省部分河流与湖泊表层沉积物中重金属的分布规律 总被引：13，自引：2，他引：13
河流的水化学组成具有多样性和易变性,而湖泊水则因其交换缓慢,即使与河流所在地区的气候条件和地球化学条件相似,其化学组成也明显区别于河流,沉积物中重金属的分布也不同.利用形态分析、相关分析和地累积指数法研究了吉林省境内部分河流、湖泊沉积物重金属分布规律.研究结果表明,伊通河和南湖重金属元素生物可利用态含量都很高,存在较大的、潜在的生态危害,Pb、Cu在有机物态中表现出明显的赋存趋势;河流沉积物中Cu、Pb、Zn与pH值显著相关,但湖泊中却相关性不显著.河流沉积物受重金属污染较严重,污染程度最高达到4级,属强污染,湖泊污染程度较轻. 相似文献
20.
陕西潼关金矿区太峪河底泥重金属元素的含量及污染评价 总被引：3，自引：1，他引：2
通过对潼关金矿区太峪河和太峪水库底泥中重金属元素总量的调查,探讨了金矿开发活动中重金属元素对河流底泥的污染程度。研究结果表明,除As外,河流底泥中重金属元素的含量与尾矿渣中重金属元素的含量变化一致,表明其主要来源于尾矿渣,但又明显高于尾矿渣。在同一地点河流底泥中重金属元素的含量平均高出河水中的1048.61～666030.08倍,呈显著富集。以邻近地区不受工矿活动影响的河流底泥重金属元素的含量均值作为评价参比值,太峪河底泥受到了Hg、Pb、Cd、Cu、Zn元素的极度污染,单项污染超标倍数及综合污染指数法评价结果表明,Hg、Pb、Cd平均污染超标倍数达366.90、217.42和149.97,是底泥中最主要的污染元素。河流底泥重金属元素的综合污染指数高达278.97,表明河流的复合污染亦呈极度状态。太峪河底泥受重金属元素极度污染的现实提示,矿区的环境防治工作已刻不容缓。 相似文献