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1.
Electron microprobe studies on soil samples with varying heavy metal contamination. 1. Methods and analysis of elements in pedogenic oxides EMA point analysis, line scan profiles and microprobe photos were performed on thin sections from 19 soil samples with variing heavy metal content to show the distribution of elements in soil particles on a microscopic level. The investigations showed that the detection limits generally have a range of 110-830 mg/kg in anorganic soil matrix respectively 80-320 mg/kg in organic soil matrix. The element specific heavy metal accumulation capacities on the pedogen oxides compared to the average content of the soil samples can be described for Co, Ni, Cu, Zn, Cd and Pb. The maximum trace element accumulations in concretions related to their element total content in the soil samples were by Co 3.170 times, Ni 6.635 times, Cu 323 times, Zn 112 times, Cd 2.000 times and by Pb 745 times. The accumulation and immobilization of heavy metals by iron oxides suggests that additions of Fe oxides could be used to reduce heavy metal availability and leaching to the subsoil on highly contaminated soils. 相似文献
2.
Behaviour of heavy metals in soils. 1. Heavy metal mobility 158 soil samples with widely varying composition were analysed for their total, EDTA, DTPA and CaCl2 extractable contents of Cd, Zn, Mn, Cu and Pb. By means of single and multiple regressions the relations between the different heavy metal fractions and the pH, organic carbon and clay content were considered. The correlations between the total, EDTA and DTPA extractable contents are very close, whereas the CaCl2 extractable contents are not or only weakly correlated with these fractions. According to these statistical results the former fractions are considered to be the total quantity (total content) and the reactive quantity (EDTA and DTPA extractable contents) of the heavy metals, whereas the CaCl2 extractable fraction represents the mobile fraction of the heavy metals in soils. The multiple regressions show that the mobile content of heavy metals is closely correlated with each of the quantity fractions and with soil pH. In the same way the proportion of the mobile fraction (in %) of the total, EDTA and DTPA extractable heavy metal content of the soil samples is closely related to the soil pH. Hereby the proportion of the mobile content of the various elements increases in the pH range 6,5 - 3 below element-specific threshold pH values (in brackets) in the order Cd (6,5) > Mn (5,7) > Zn (5,3) > Cu (4,5) > Pb (3,5). In the pH range 6,5 - 7,5 mainly Cu and to a lesser degree also Pb show an increasing mobility due to the influence of soluble organic substances. 相似文献
3.
为了研究和分析北京市朝阳区（五环内）土壤重金属的分布特征及影响因素,通过居住绿地、公园绿地、街旁绿地以及附属绿地（包括公共设施用地、对外交通用地和市政设施用地）4种土壤利用类型分别进行了土壤重金属铜（Cu）、锌（Zn）、镉（Cd）、铅（Pb）以及土壤pH值、有机质的测定。结果表明:表层土壤中的重金属平均含量,除Pb外,均高于中国土壤背景值,尤其是重金属Cd,已达到0.26 mg/kg,超过了国家土壤环境质量1级标准;从土壤利用类型上来看,Cu在附属绿地土壤含量最高,达到33.576 mg/kg,Zn在居住绿地土壤含量最高,达到80.636 mg/kg,Cd在街旁绿地土壤含量最高,达到0.296 mg/kg,Pb在公园绿地土壤含量最高,达到24.706 mg/kg;在空间分布上,重金属Cu和Zn空间分布格局相类似,整体呈由西北向东南递减趋势,而Cd高值区在中部,整体北部高于南部,重金属Pb整体上呈由西南向东北递减趋势;通过相关性分析可知,土壤pH值对土壤重金属含量没有明显的影响,而土壤有机质与重金属Zn,Cd和Pb的含量有明显的相关性;4种重金属呈显著正相关（p<0.01）。 相似文献
4.
Robert Mayer 《植物养料与土壤学杂志》1978,141(1):11-28
Adsorption isotherms as regulators controlling heavy metal transport in soils The adsorption and desorption of Pb2+ and Cd2+ from equilibrium solutions with heavy metal contents up to 5000 μg/1 were determined in bulk experiments for soil samples from an acid Braunerde developed in loess loam, taken from the humic surface layer of the mineral soil (0–10 cm) and from the subsoil fairly free from organic matter (30–40 cm). Pb and Cd in solutions were determined by flameless atomic absorption spectroscopy. Pb was more strongly retained in the solid phase than Cd, and higher amounts of heavy metals were retained in the humic surface soil than in the subsoil free of organic matter. In the case of Pb adsorption/desorption showed slight hysteresis in the subsoil. The quantity/intensity (Q/I) relationships found in the experiments could be described by the Freundlich equation. The Q/I-relationships were substituted in the general transport equation. With a simulation model the transport of Pb and Cd through the soil with vertical water flow was calculated by the use of the Continuous Simulation Programming Language (CSMP). Two different cases were considered: a small, continuous increase in the heavy metal input of the soil surface, and a high, instantaneous peak input. Simulation of the transport and distribution mechanisms induced by the inputs over a period of 10 years showed strong retention of lead in the surface layer and consequently a strong damping of the concentration peak in the soil solution. In contrast, cadmium is distributed more quickly over the whole profile, yet the concentration peak in the solution phase is, too, damped considerably in the surface layer by temporary retention in the solid phase. The results of the simulation runs are in accordance with the situation in real soils where often strong accumulation of Pb is found in the top soil, while Cd is accumulated only slightly. 相似文献
5.
W. R. Fischer 《植物养料与土壤学杂志》1984,147(4):449-455
Complexation of Cu, Pb, and Cd by water soluble humic substances I. The polarographic proof of heavy metal complexation by water soluble humic substances The complexation of Cu, Pb, and Cd by water soluble humic substances in aqueous solution decreases the peak height of differential pulse polarograms. Using the law of mass action with respect to definite complex formulae, empirical stability constants can be calculated, which are roughly independent from the presence of other cations. 相似文献
6.
Behaviour of heavy metals in soils. 2. Extraction of mobile heavy metals with CaCl2 and NH4NO3 156 soil samples from arable fields, grassland and forest stands were analysed for the CaCl2? and NH4NO3? extractable contents of Cd, Zn, Mn, Cu and Pb. The average amounts of Cd, Zn, Cu and Pb extracted with CaCl2 are higher compared with NH4NO3 whereas the relation for Mn is vice versa. The proportion of the NH4NO3? extractable contents in percent of the CaCl2? extractable contents of Cd, Zn and Pb decrease with increasing pH, whereas the contents of Mn and Cu increase. Inspite of a differing extraction behaviour of the two salt solutions the CaCl2? and NH4NO3? extractable amounts of Cd, Mn, Zn und Pb are highly correlated and can be converted one into another. The mobile (CaCl2, NH4NO3) proportion of the corresponding total, EDTA and DTPA heavy metal contents is in close relation to the pH of the soils. Using CaCl2 solution the threshold pH values for an increasing mobility decrease in the order Cd > Mn > Zn > Cu > Pb, using NH4NO3 as extractant the order is Mn > Cd > Zn > Cu > Pb. In the case of CaCl2 as extractant soluble chloro-Cd-complexes will be formed so that the Cd mobility in soils will be overestimated in most cases. 相似文献
7.
水稻子实对不同形态重金属的累积差异及其影响因素分析 总被引：3，自引：0，他引：3
在分析成都平原核心区土壤重金属(Cd、Cr、Pb、Cu、Zn)全量、各形态含量及相应点位种植的水稻子实重金属含量的基础上,通过统计分析、空间插值及线性回归方程的模拟,研究了土壤Cd、Cr、Pb、Cu、Zn全量的空间分布状况、各形态重金属含量统计特征,以及水稻子实对重金属各形态的累积差异及其影响因素。结果表明,成都平原水稻土重金属污染较轻,除Cd外,均低于国家土壤环境质量二级标准。土壤中重金属的可交换态含量均较低,Cd主要以铁锰氧化态存在,Cr、Cu、Zn、Pb主要以残渣态存在。水稻子实对5种重金属的累积效应顺序为:Cd>Zn>Cu>Pb>Cr。与水稻重金属累积关系密切的重金属活性形态(可交换态、碳酸盐结合态、铁锰氧化物结合态和有机物结合态)主要有:Cd的碳酸盐结合态、Cr的可交换态、Pb的有机物结合态和Cu的碳酸盐结合态含量;Zn各活性形态对水稻子实含量的影响不明显。土壤理化性质对不同活性形态重金属元素的影响效应各不相同。活性态Cd主要受有机质、pH和容重的影响;活性态Cr与pH、有机质、CEC和容重密切相关;活性态Pb与有机质、容重、中细粉粒、砂粒等均有密切的关系;Cu的活性主要受粘粒、有机质含量的影响;Zn的有效性主要受pH、有机质、砂粒、容重的影响。总的看来,对土壤Cd、Cr、Pb、Cu、Zn各活性形态含量影响效应较强的是有机质、pH、容重,而与土壤吸附性能密切相关的颗粒组成、CEC的影响不甚明显。 相似文献
8.
Flux balances and current rates of change of heavy metal stores in forest ecosystems of the Soiling The inventory of the heavy metals Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb is calculated for a beech and a spruce forest ecosystem in the Soiling mountains on the basis of measured concentrations in the vegetation and soil compartments and their dry mass per hectare. The inventory is compared with measured heavy metal fluxes coupled with precipitation above and below the canopy, with seepage water fluxes below the rooting zone (50 cm depth), with litterfall, and with the current increment to biomass. The ratios between heavy metal stores in the forest floor layers (table 3) and the annual flux with litterfall (table 4) show decreasing tendency for liberation of the elements by decomposition of organic matter (OM) in the following order: Mn>OM>Ni>Cd>Cu>Cr ≈? Zn>Co ≈? Fe ≈? Pb Manganese is set free faster than total organic matter. The flux balances for the total ecosystems (table 4) show input > output in the case of Cr, Fe, Cu, Cd, and Pb; input ≈? output for Ni and Zn; input < output for Mn and Co. Heavy metal stores in mineral soil are decreasing by percolation losses and increment to biomass (mainly wood) in the case of all elements investigated, except Zn (under beech), Cd and Pb (table 4). The concentrations of Cu and Pb in the forest floor layers have reached levels at which deleterious effects on microorganisms and litter decomposition are to be expected. 相似文献
9.
The influence of organic matter in the translocation of metals between soil and soil solution of an acid forest soil Water extracts were prepared from soil samples which were collected from a soil profile showing very little variation in the texture down to a depth of 120 cm and thus only little translocation of clay in the soil profile. The aim of the study was to describe the distribution between soil and soil solution of several metals like Cu, Pb, Cd, Zn, Al and Mn as a function of humic substances, electrolyte concentration and pH. From the experimental results the following hypothesis on the reaction mechanisms involving metals and humus derived substances has been deduced. The metals Cu, Fe, Al and Pb are mobilized through complexation by soluble humus substances in addition to the usual pH dependent desorption and dissolution of hydroxides. This mobilization determines the solution concentration of Cu and Fe at pH > 3.7 and Al and Pb at pH > 4.2. Al, Fe and Pb are complexed selectively by high molecular weight humus derived substances which undergo adsorption on soil mineral surfaces. Cu interacts with low molecular weight humus derived substances which are not easily adsorbed by the mineral surfaces. Zn, Cd and Mn primarily undergo sorption and are thus controlled by pH and electrolyte concentration of solutions because their complexation with humus derived substances seems to be weak or nonexistant. It is further postulated that the humus derived substances mobilize Al3+ and Fe3+ ions. By this, other metals like Cd, Zn, Mn, Ca and Mg can occupy the free exchange sites. 相似文献
10.
Christian B. Sekomo Egide Nkuranga Diederik P. L. Rousseau Piet N. L. Lens 《Water, air, and soil pollution》2011,214(1-4):321-333
The Nyabugogo natural wetland (Kigali City, Rwanda) receives all kinds of untreated wastewaters, including those from industrial areas. This study monitored heavy metal concentrations (Cd, Cr, Cu, Pb, and Zn) in all environmental compartments of the swamp: water and sediment, the dominant plant species Cyperus papyrus, and fish (Clarias sp. and Oreochromis sp.) and Oligochaetes. Cr, Cu, and Zn concentrations in the water were generally below the WHO (2008) drinking water standards, whereas Cd and Pb were consistently above these limits. Except Cd, all metal concentrations were below the threshold levels for irrigation. The highest metal accumulation occurred in the sediment with up to 4.2 mg/kg for Cd, 68 mg/kg for Cu, 58.3 mg/kg for Pb, and 188.0 mg/kg for Zn, followed by accumulation in the roots of C. papyrus with up to 4.2 mg/kg for Cd, 45.8 mg/kg for Cr, 29.7 mg/kg for Cu, and 56.1 mg/kg for Pb. Except Cu and Zn, other heavy metal (Cd, Cr, and Pb) concentrations were high in Clarias sp., Oreochromis sp., and Oligochaetes. Therefore, there is a human health concern for people using water and products from the swamp. 相似文献
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13.
Concentrations of chemical elements in tree roots including heavy metals from air pollution Total concentrations of P, S, Na, K, Mg, Ca, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb were measured in roots from beech, spruce, ash, maple and a forest herb (Mercurialis perennis). The root samples were taken from a site with an acid soil type (Saure Braunerde) and from a site with calcareous soil (Rendzina). All elements except Mn, Zn and Pb (on acid soils) and Ca (on calcareous soils) showed higher concentrations in finest roots (<1 mm diameter) compared to fine roots (1–2 mm). In the case of the toxic heavy metals, this is interpreted as a consequence of reduced root uptake due to physiological processes or to organic complexing, followed by an accumulation at the root surface. Compared with aboveground plant parts, roots show accumulation of Al, Pb, Cd and Zn, indicating reduced translocation from roots to shoots. Roots from acid soil show higher concentrations of P, Mn, and Pb than in calcareous soil. The concentrations of Al and heavy metals in the roots are considered to be a consequence of the contamination of the investigated forest sites by long-range transported air pollutants, i.e. acid precipitation and deposition of heavy metals. 相似文献
14.
土壤可见光-近红外反射光谱与重金属含量之间的相关性 总被引：13，自引：0，他引：13
发展基于反射光谱技术的快速、简便、低成本的土壤重金属信息提取方法是区域土壤重金属污染治理所需要的。选择江西贵溪铜冶炼厂污染区,分析了9种重金属元素(Cu、Pb、Zn、Cd、Co、Ni、Fe、Mn及Cr)与土壤可见光-近红外反射光谱之间的相关性及其相关的原因。研究表明,研究区土壤中存在Cu(含量介于66.71~387 mg kg-1之间)和Cd(含量介于0.36~6.019 mg kg-1之间)的强烈富集。土壤重金属含量与反射光谱之间存在显著相关,污染元素Cu的最高相关系数为-0.87,Pb、Zn、Co、Ni、Fe的最高相关系数达到高度相关(|r|>0.80),Cr、Cd、Mn的最高相关系数达到显著相关(|r|>0.70)。微分光谱适于获取土壤中的重金属元素信息,利用组合波段能显著提高相关性。Cu与反射光谱之间的相关性主要受有机质的影响;Pb、Zn、Co、Ni主要受黏土矿物和铁锰氧化物的影响;Cr与反射光谱之间的相关性同时受有机质和黏土矿物的影响。 相似文献
15.
Evaluation of Heavy Metal Pollution in the Arabian Gulf Using the Clam Meretrix meretrix Linnaeus, 1758 总被引：1，自引：0，他引：1
Hamad Alyahya Amel H. El-Gendy Saleh Al Farraj Magdy El-Hedeny 《Water, air, and soil pollution》2011,214(1-4):499-507
The present study is an attempt to assess the heavy metal contamination in the marine environment of the Arabian Gulf of Saudi Arabia. The concentrations of heavy metals in water and the soft tissues of the bivalve species Meretrix meretrix Linnaeus, 1758, from different stations along the Arabian Gulf coastline, were determined during the summer season of 2008. Bioaccumulation of some heavy metals (Cd, Pb, Cu, and Zn) in fresh parts of the clam (M. meretrix) was measured by an atomic absorption spectrophotometer. The average concentrations of heavy metals in the clam tissues were 0.224?C0.908, 0.294?C2.496, 3.528?C8.196, and 12.864?C24.56 mg/kg wet weight for Cd, Pb, Cu, and Zn, respectively. In water, the mean concentration values of these metals were arranged in the following descending order: Pb > Cu > Zn > Cd. The heavy metal concentrations in tissues of M. meretrix were within the acceptable standards set by the US Environmental Protection Agency, the Commission Européenne, and the Food and Drug Administration of the USA. From the human public health point of view, these results seem to show no possibility of acute toxicities of Cd, Cu, Pb, and Zn if the edible clam is consumed. It is recommended that relevant authorities should carry out a continual assessment on the levels of these pollutants in the studied area. 相似文献
16.
W. R. Fischer 《植物养料与土壤学杂志》1986,149(1):120-129
Complexation of Cu, Pb, and Cd by hot water soluble humic substances II. The stability of the complexes Soxhlet extracts of terrestrial and underwater soils were used to determine polarographically the stability of heavy metal complexes. Stability constants were calculated using the law of mass action. They were independent of concentration at levels higher than 2 mg Cd or 5 mg Pb/g humic substance, respectively. For Cu, constants increased below 8 mg Cu/g. At pH values in the polarographic medium between 4 and 8, the stability of the Pb complexes increased markedly with increasing pH. In most cases this was also valid for the copper complexes, cadmium complexes were either not influenced by pH or stability maximum was obtained at about pH 5. Drying of the samples before extraction did not alter significantly complex stabilities. Complex stabilities increased with increasing degree of humification for oligotrophic, underwater soils and nutrient poor, low moor peat, but reduced horizons of eutrophic gyttjas exhibited lower stability values. 相似文献
17.
《Communications in Soil Science and Plant Analysis》2012,43(4):390-407
The To Lich and Kim Nguu Rivers, laden with untreated waste from industrial sources, serve as sources of water for irrigating vegetable farms. The purposes of this study were to identify the impact of wastewater irrigation on the level of heavy metals in the soils and vegetables and to predict their potential mobility and bioavailability. Soil samples were collected from different distances from the canal. The average concentrations of the heavy metals in the soil were in the order zinc (Zn; 204 mg kg?1) > copper (Cu; 196 mg kg?1) > chromium (Cr; 175 mg kg?1) > lead (Pb; 131 mg kg?1) > nickel (Ni; 60 mg kg?1) > cadmium (Cd; 4 mg kg?1). The concentrations of all heavy metals in the study site were much greater than the background level in that area and exceeded the permissible levels of the Vietnamese standards for Cd, Cu, and Pb. The concentrations of Zn, Ni, and Pb in the surface soil decreased with distance from the canal. The results of selective sequential extraction indicated that dominant fractions were oxide, organic, and residual for Ni, Pb, and Zn; organic and oxide for Cr; oxide for Cd; and organic for Cu. Leaching tests for water and acid indicated that the ratio of leached metal concentration to total metal concentration in the soil decreased in the order of Cd > Ni > Cr > Pb > Cu > Zn and in the order of Cd > Ni > Cr > Zn > Cu > Pb for the ethylenediaminetetraaceitc acid (EDTA) treatment. The EDTA treatment gave greater leachability than other treatments for most metal types. By leaching with water and acid, all heavy metals were fully released from the exchangeable fraction, and some heavy metals were fully released from carbonate and oxide fractions. The concentrations of Cd, Cr, Cu, Ni, Pb, and Zn in the vegetables exceeded the Vietnamese standards. The transfer coefficients for the metals were in the order of Zn > Ni > Cu > Cd = Cr > Pb. 相似文献
18.
污灌对潮土重金属含量及分布的影响——以开封市化肥河污灌区为例 总被引：26，自引：2，他引：24
以开封市化肥河污灌区为例,研究了污水灌溉对潮土中重金属(Cd、Pb、Cr、Cu、Zn、Ni和 As)含量及分布的影响。结果表明,污水灌溉已经导致了该区潮土较明显的重金属累积,其中Cd和As平均含量分别达1．70 mg/kg和26．28 mg/kg,远远超出了土壤环境二级标准值。进入潮土的重金属主要累积在潮土的耕作层,随着土壤深度的增加,重金属含量逐渐减少;相对其他重金属而言,As更易于在潮土表层滞留。污灌区潮土 Cu、As与Cd含量与距污染源距离呈线性相关。相关分析表明,污灌区土壤Cu、Zn、Pb、Ni和As含量与土壤理化性质及其他重金属含量有关,而土壤Cd和Cr含量则与其他重金属含量及土壤性质的相关性不明显。 相似文献
19.
广东大宝山矿区植物对重金属的富集特征 总被引：4，自引：0，他引：4
对大宝山矿区自然定居和人工种植的13种优势植物根际土壤污染状况及其对重金属的富集特征进行研究.结果表明,大宝山矿区土壤受重金属Cd、Pb、Zn、Cu污染,其中以Cd、Cu的污染最为严重.在调查的13种优势植物中,铺地黍地上部分的Pb含量达到1 214.00 mg/kg,泡桐叶中Cu含量达到1 024.80mg/kg,超过了Pb和Cu超富集植物含量的临界值(1 000 mg/kg);其运转系数分别为1.77.13.74,都大于1.0,符合超富集植物的标准,表明铺地黍可能是Pb的超富集植物,泡桐可能是Cu的超富集植物.除铺地綦、泡桐外,其他11种优势植物的重金属吸收能力没有达到超富集植物的标准,但它们能在此区域定居,表现出对重金属有较强的耐性,其中象草、纤毛鸭嘴草、芒萁、五节芒、马尾松对重金属复合污染胁迫的耐性较强,可作为大宝山矿植被重建的先锋物种. 相似文献