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潮间带沉积物中重金属污染评价及生物有效性研究进展 总被引：1，自引：0，他引：1
潮间带是一个典型的环境脆弱带和敏感带,极易受到人类活动的破坏.潮间带重金属除了直接对潮间带生物有影响外,还可以通过过食物链的富集和放大作用影响人类健康,同时由于潮间带水动力和生物活动的影响,造成重金属的重新分布和释放,产生重金属的"二次污染",直接危害近岸环境.开展重金属元素在潮间带沉积物中含量、赋存形态、污染评价及其生物有效性已成为目前环境科学领域中十分重要的研究内容和任务,国内外学者均对河流沉积物重金属污染开展了大量的研究.文章从这4个方面阐述了潮间带沉积物重金属研究进展,以期为潮间带沉积物重金属研究提供一定的参考. 相似文献
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指出了河流是为全球人口提供淡水资源的重要渠道,其水环境状况与人类的健康、生活、生产有着千丝万缕的联系。以河流沉积物重金属研究为背景,对沉积物重金属污染研究进展和河流沉积物重金属研究方法及生态风险评价方法进行了综述和分析。结果表明:BCR法可以有效提供更多更全面关于重金属形态分析的信息;河流广泛污染以及各种现有重金属形态在河流中的不同影响评价研究却不够充分;单一重金属元素污染评价研究较为成熟,而能够反映沉积物污染环境因子的综合效应的评论方法却不够深入;在各流域内加强多种重金属和其他元素的协同污染评价研究,以解决重金属污染是否呈元素关联形态;根据评估目的以及研究的侧重点选择适当的评估方法,来确保数据结论的准确性,为水体沉积物中重金属的研究提供科学有效的实验方法。最后,提出了对在国内流域水环境全面的背景数据库依托下,研究的侧重点应偏向流域重金属污染治理方法方面,并研究经济、环保的生态恢复手段,从根本上改变污染的现状。 相似文献
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对杭州西溪湿地不同水体干扰和沉积过程干扰类型的底泥重金属进行研究,分析了底泥表层和剖面重金属Cu、Zn、Cr、Pb、Cd、Hg和As的含量及分布特征,探讨不同湿地保护措施和水体干扰类型等因素对底泥重金属含量的影响及重金属的可能来源,在此基础上,运用单因子污染指数、H(a)kanson潜在生态风险指数和基于沉积物质量基准的方法对底泥污染的生态风险进行了评价.结果表明,底泥7种重金属含量平均值均低于<土壤环境质量标准>(GB 15618-1995)的二级标准.除Hg和As外,其他元素含量平均值高于当地土壤元素背景值.重金属元素间的不同相关性指示底泥污染物的多种来源.Zn和Cd在底泥中的含量要明显高于土壤,指示底泥中有不同于土壤的重金属污染来源.空间上,底泥污染物的分布与人为活动干扰的强度具有较为密切的关系,景区外围样点污染物含量要高于景区内样点,且景区外围样点重金属污染物仍然处于一个增加的趋势,而景区内污染物输入则呈现为减少的态势.水体类型对底泥重金属的影响一般表现为封闭池塘和大水面中底泥重金属元素含量高于普通河道中的含量.H(a)kanson潜在生态风险评价表明,西溪湿地的整体生态风险较轻微,元素中Cd和Hg具有中等生态风险,其余为轻微生态风险.基于沉积物质量基准的风险评价结果则有所不同. 相似文献
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选取洪泽湖为研究对象,于2008年采集洪泽湖沉积物样品17个,以沉积物中6种重金属（Cu、Cd、Pb、Zn、Ni、Cr）的总量为主要研究内容,运用潜在生态危害指教法对沉积物中的重金属污染状况进行了评价。结果表明：洪泽湖Cu、Ni、Zn、Pb、Cr污染的主要分布在东部和北部湖区,Cd污染主要在西部湖区。Pb是全湖污染最严重的重金属。Cu、Ni、Zn、Pb、Cr的潜在生态危害较小（低风险）,Cd的潜在生态危害较大（高风险）,总的潜在生态危害为低风险,Cd的影响最大（达到81％）。 相似文献
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指出了河口沉积物重金属富集状况是河流水环境质量的重要指示标志。选取胶州湾典型大沽河口为研究区,系统采集了16个站点河流沉积物样品,测定了Zn、As、Cd、Cr、Cu、Pb共6种重金属元素含量,通过数理统计特征和站点分析,得到了重金属元素在区域内的数据变异特征,并对河口沉积物的重金属来源进行了初步判别,采用潜在生态风险指数法得出了河口沉积物分布生态风险规律。研究表明:研究区内重金属元素空间变异不大,变异系数值保持在较低水平上,Cr和As表现出低度变异,其余元素都属于较低程度的中等变异;结合采样数据特征与站点位置分析,得到各重金属元素含量的空间分布图,研究发现胶州湾大沽河口感潮河段及两侧潮滩是重金属最为富集的地带,其存在的重金属污染风险也最高;潜在生态风险指数评价得出重金属元素中Pb的潜在生态风险较大,平均为41.69,属于中等潜在生态风险水平,其余元素生态风险处于低度水平。 相似文献
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淮南矿区塌陷水域沉积物营养物质和重金属现状调查与评价 总被引：1，自引：0，他引：1
对淮南矿区潘集杨庄塌陷水域沉积物中的营养盐及重金属元素进行了分析,揭示了其环境现状和受污染程度。结果表明:潘集杨庄塌陷水域沉积物OI和ON属于尚清洁级别。沉积物的重金属污染主要以Cd元素为主,并依据潜在生态风险指数,表明该区域重金属总潜在风险达到强生态危害程度。 相似文献
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指出了水体重金属污染的来源为工业生产。针对该现象,研究了重金属在水体、大气和土壤之间的相互转化与关联,因重金属污染水体对动植物和人类有巨大的危害,故着重阐述了几种常见的重金属污染水体处理技术及其进展,如吸附法、化学沉淀法和生物法。通过对这几种方法的基本原理与近些年的研究结果的分析,为后期重金属污染水体治理人员提供相应参考。 相似文献
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《绿色科技》2019,(24)
为了了解浙江省金华市某100亩农田土壤中重金属污染情况,对该地进行了土壤调研。采集了该地的30个表层土壤样品以及3个土壤剖面,分析了6种重金属元素的含量以及pH值和有机质,初步了解了土壤重金属污染状况;同时采集各20个表层、中层土壤样品,通过BCR形态分级方法测定结果,确定了不同的重金属其污染来源;利用生物有效性分析,确定了研究区重金属的污染情况;最后对当地进行了土壤重金属污染评价分析。研究结果得出研究区土壤重金属Cd含量超标,其他重金属均未超标。根据重金属形态分级、以及土壤剖面分析得出重金属:Pb以残渣态和可还原态较高;Zn、Cu、Cr、Ni主要以残渣态为主,Cd以弱酸提取态和可还原态为主。依据生物有效性分析,得出Pb具有潜在的危害,Cd在中层的生物活性系数K1急剧上升,对作物易造成危害。利用RSP污染评价方法得出Pb和Cd的污染程度为中度污染。因而,提出了在下一步的修复工作中需要针对不同来源,进行土壤中相应重金属含量的控制。 相似文献
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In this study, we combined a program to optimize forest road alignments with a method for prediction of surface erosion and
related sediment delivered to streams. Combining the forest road design program with the high-resolution digital elevation
model made it possible to estimate soil sediment based on a standard methodology, because a relatively accurate road prism
could be generated. The combined program properly places and spaces drainage structures based on the Washington State Forest practice board manual. We applied the program to a part of Capitol State Forest in Washington State and optimized horizontal and vertical alignments
while estimating movement of soil sediment from roads to streams. We discussed the effects of road surface materials, near-stream
culvert distance to stream, and out-sloped forest road template on total road costs and soil sediment delivered to streams.
Using lower quality rock surfacing reduced total costs, but the amount of soil sediment from lower quality rock surfacing
was 1.5 times more than that on a higher quality rock traction surface. Therefore, lower quality rock surfacing should not
be used near the stream. The placement of near-stream culverts 15 m upstream and out-sloped road template were examined using
a traction surface on 15-m sections upstream and lower quality rock surfacing on other sections in order to reduce soil sediments
to the stream and total costs. As a result, placing near-stream culverts 15 m upstream and using an out-sloped road template
significantly reduced total road cost and soil sediment. Finally, we optimized horizontal and vertical alignments while limiting
soil sediment to a specified maximum level. The model successfully optimized forest road alignments, which reduced total road
cost as well as soil sediment. 相似文献
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土壤/沉积物中的铁、锰和铝的(氢)氧化物对磷和重金属的吸附解吸,在极大程度上控制着这些元素在土壤/沉积物和水体中的浓度、形态和迁移转化,关系到人类健康。本文列举了磷和重金属的环境效应,以铁、锰和铝的(氢)氧化物为例,阐述了土壤/沉积物中氧化物的组成、氧化物吸附磷和重金属的3种机制(内层络合、外层络合和存留于扩散团间)与吸附模型(等温吸附的经验和半经验方程与表面络合模型),分析了氧化物对磷和重金属行为调控的影响因素,指出氧化物间可能存在的竞争或协同吸附现象。认为当前结合各种现代测试技术在原子或分子水平上认识氧化物-水界面的吸附反应本质以及多晶型或不同氧化物共同参与下的多界面复杂反应过程意义重大。 相似文献
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A well developed network of roads must exist as a necessary infrastructure system in modern forestry to facilitate forest operations. But forest roads have the potential to disrupt the drainage characteristics of watersheds and lead to negative impacts on the environment with increased erosion and sediment yields. Numerous factors affect surface erosion of roads and sediment production potential; determining and ranking them could be a guide for management decisions to erosion control. In this study, the CULSED model (as an extension of ArcGIS) was used to estimate sediment delivery and the distribution of a road network, given the existing culverts. Using the model, some culverts were added to the road network around places with high sediment delivery in order to minimize it. After a correlation analysis and adjustment between sediment production and the factors, i.e., road width, road gradient, age of road and vegetation cover, the trend of changes in sediment delivery with model changes in the input was investigated with a sensitivity analysis of the model. The results show that adding new culverts to the road resulted in a significant reduction of sediment delivery. The most important factor affecting sediment delivery was road width, followed by road gradient, vegetation cover and age of road. Road width and gradient were positively correlated with sediment delivery, while vegetation cover and age of road were negatively correlated. The best model to show the relation between sediment delivery and road width as well as with road gradient was a linear model, for vegetation cover a cubic equation and for road age a power model. The results of sensitivity analysis showed that sediment delivery had the greatest sensitivity to changes of road width and was least sensitive to changes in the age of the road. This model can help to estimate sediment delivery with its spatial distribution, which can be used for optimization of cross drain systems and strategies of sediment control. Application of the model requires field trials to acquire the necessary input data. The reliability of our results is a function of the accuracy of inputs, especially digital elevation model. 相似文献
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Access systems are a necessary element of resource production in bottomland hardwood sites. However, road building may have a detrimental effect on hydrologic function of the site. This report describes initial results of a study designed to examine the effect of different road surfacing treatments on water quality.
Four surfacing treatments installed on two test roads included native soil, native soil with vegetative stabilization, 6 cm of gravel, and 15 cm of gravel over geotextile. During the first flooding season periodic sampling measured floodwater suspended sediments and location of erosion and sediment deposition within the road prism. Initial results suggest that sediment movement was confined to the road right-of-way, with no statistically significant sedimentation effects detected beyond the clearing limits of the road. The study is continuing for another field season. 相似文献
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Contrasting impacts of localised versus catastrophic oil spills in mangrove sediments 总被引：1，自引：0，他引：1
Several truckloads of mixed waste oil were dumped onto a short section of road and into the intertidal wetlands near Cairns, Queensland in January, 1994. The oil contaminated a band of mangroves 15–44 m wide along approximately 200 m of road. Impacted marsh included Melaleuca forest and high-intertidal mangroves. The initial concentrations of petroleum hydrocarbons in surface sediments reached 17% of the dry weight in heavily impacted areas. These high concentrations observed in limited spatial areas were similar to those observed over large spatial areas after a catastrophic oil spill in Panama in 1986. No large scale biological damage was observed from this localised spill. Clean up efforts and natural dissipation processes reduced sediment hydrocarbon loads to non-acutely toxic levels in 1.5 years in the intertidal mangroves. High hydrocarbon concentrations remained in the Melaleuca sediments for at least two years post spill. Internal molecular markers were used to detail hydrocarbon dissipation and degradation rates. This study provides a contrast between impacts of localised versus catastrophic oil spills in tropical mangrove habitats. 相似文献
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《林业研究》2020,31(4)
Soil characterization is a vital activity to develop appropriate and effective restoration protocols for mine wastelands while insights into the total content of heavy metals in the soil is an important step in estimating the hazards that the metals may pose to the vital roles of soil in the ecosystem.This study addressed the following research questions:(1) To what extent do the physico-chemical characteristics vary between mine waste sediments and the nearby forest soil?(2) Are the concentrations of heavy metals high enough to be considered as toxic?and(3) Are heavy metals present in mine waste sediments potential sources of pollution?We hypothesized that the physicochemical characteristics of mine waste sediments are less favorably for plant establishment and growth while the concentrations of heavy metals are very high,thus restricting the success of revegetation of mine waste lands.Mine waste sediments were sampled following a diagonal transect across tailings dams,overburden dump sites and the local forest soil from the top layer(0-20 cm) using a closed auger.Samples were analyzed for arsenic,barium,lead,cadmium,cobalt,copper,chromium,nickel,vanadium,and zinc as well as for soil physico-chemical properties.The mine waste sediments were dominated by silt whilst the forest soil by sand particles,with significantly high bulk density in the former.Both the forest soil and overburden sediments were acidic than the alkaline tailings dam sediment.Total organic carbon and nitrogen contents were significantly low in mine wasteland substrates but the concentration of Ca and Mg were significantly higher in tailings dam substrate than the forest soil.The concentrations of available P,K and Na were similar across sites.The mean concentrations of heavy metals were significantly(p 0.01) higher in mine waste sediments than the forest soil;except for cadmium(p=0.213).The order of contamination by heavy metals on the tailings was CuCo Ba Ni As Zn Pb Cr V Cd,and that on the overburdens was Cu Co Ba Ni ZnCr Pb V As Cd.The pollution load index(PLI)was nearly twice higher for the tailings dam(8.97) than the overburden(5.84).The findings show that the copper mine wastes(the tailings dams and overburden waste rock sites)are highly contaminated by heavy metals;which,in turn,might pose serious hazards to human health and agricultural productivity.In addition,poor macro-nutrient availability,substrate compaction and soil acidity(particularly on overburden sites) coupled with toxic level of heavy metals would be the main challenges for successful phytostabilization of copper mine wastelands. 相似文献
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The accumulation of metals in natural systems is common in many industrial societies, with variation in historical output reflected in the sediment record of these systems. This study of the Severn Estuary, south-west U.K. clearly demonstrates such temporal trends for three commonly occurring heavy metals (copper, lead and zinc) within saltmarshes whose accretion period has spanned the last few centuries. The results obtained support previous data for metal trends in the Severn, but importantly, add hitherto unrecorded detail to small-scale concentration variations with depth which have increased our knowledge of how this system behaves in respect of both metal storage and sediment cycling.In addition, the accretion and erosional cyclicity of the Severn Estuary means that there are up to 4 marsh units present, each unit covering finite periods of time from initiation to the present day. As the younger marshes accrete lower in the tidal frame, they are represented by thicker sedimentary sequences, and, therefore, with respect to pollutant content and sedimentary detail, represent expanded sequences with reference to the older marshes. The presence of these inter-marsh unit relationships in conjunction with the new information on metal trends is used to add detail to the overall temporal trends in metals shown by the older marsh sequence. The resulting pollution trends demonstrate a distinct 3-fold division, including low, pre-industrial levels, leading up into a zone of rapidly increasing concentrations relating to the period of post industrial-revolution industrial growth, and finally, an upper zone of declining concentrations representing industrial decline and general increase in environmental awareness, resulting in reduced metal inputs. The fine detail provided by this methodology also reveals some interesting smaller-scale variation, linked to specific catchment events. The onset of the second world war coincides with an unexpected decline in metal levels, at a time when production was increasing. It is also at this time, however, that the estuary was in a regime of net erosion, and so the reworking of less polluted sediments also becomes significant.As a result of the increased detail provided, it is possible to establish that metal trends in salt marsh sediments owe their temporal variability both to socio-economic activities, but also to system hydrodynamics, and that a knowledge of both is important in the successful interpretation of metal/depth trends. 相似文献