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1.
为了系统地探讨洞庭湖平原土壤铅(Pb)活动性特征及其影响因素,本次研究在常德市、益阳市、株洲市共采集了110件水稻根系土样品,讨论了土壤Pb活动态含量和活动系数与有机质、pH值、阳离子交换量(CEC)等土壤理化性质的相关性,并据此建立了Pb活动态含量和活动系数的预测模型。研究结果表明:土壤Pb含量、pH值、有机质含量、CEC和风化程度都是影响Pb活动态含量及活动系数的主要因素。pH值、CEC和有机质含量都会影响土壤缓冲能力,进而影响Pb的活动性。土壤Cd含量和Zn/Pb值也与Pb活动态含量有显著相关性;在不同的浓度梯度内,Cd与Pb的交互作用不同;土壤具有较高的Zn/Pb 值时,Pb活动态含量较低。采用逐步回归法建立了土壤Pb活动态含量以及活动系数的预测模型,土壤Pb活动态含量用土壤pH、Pb含量、CEC和Na2O/K2O值进行预测,活动态系数用pH、CEC、SiO2/Al2O3值进行预测,预测效果均较好。 相似文献
2.
土壤重金属元素地球化学行为是目前国内外研究的热点。研究显示重金属元素地球化学行为与土壤理化性质有密切关系。本文选择河北平原农田为研究区,采集了325个根系土样品,测定了Pb、Hg有效态含量,并探讨了影响其地球化学行为的主要因素。研究表明:(1)Pb、Hg水溶态和离子交换态与土壤p H值呈显著负相关关系,土壤酸化使Pb、Hg有效性增加,直接导致农作物中Pb、Hg含量增加,保持土壤p H值在弱酸性至弱碱性范围,防止土壤酸化,可以降低重金属危害。(2)土壤中有机质含量与Pb、Hg全量呈显著的正相关性,但与水溶态和离子交换态呈负相关。所以土壤中有机质的增加可以降低Pb、Hg元素水溶态和离子交换态含量。(3)随着土壤黏粒的增加,Pb、Hg水溶态和离子交换态含量降低,说明黏粒可以吸附一定量的重金属离子,与重金属元素Pb、Hg地球化学行为存在一定关系。土壤p H值、有机质、黏粒是控制重金属元素Pb、Hg地球化学行为的重要因素。 相似文献
3.
内江市双桥乡土壤重金属含量及风险评价 总被引：3，自引：0，他引：3
以四川省内江市双桥乡为研究区域,调查分析各类土壤中重金属（Cu、Pb、Zn、Cd、Cr、As、Hg、Ni）含量情况。采用单因子污染指数、内梅罗综合污染指数和富集因子评价方法,对土壤重金属污染状况进行评价。研究结果表明,该地区Cd、Cr、Cu、Ni、Pb、Zn元素平均含量高于成都经济区、四川省、中国土壤背景值,有一定程度的Cd、Cr、Cu、Ni、Pb、Zn富集,Hg元素有个别样点含量偏高,并且单因子重金属的污染程度依次为：Cd〉Ni〉Zn〉Cu〉Cr〉Pb〉As〉Hg,Cd在绝大部份区域存在轻微污染,由内梅罗污染指数和富集因子评价得出区域综合污染程度为轻度。 相似文献
4.
《Applied Geochemistry》2006,21(9):1613-1624
Ingestion of soil is a common behaviour in young children as a means of exploring their surroundings. Much attention has been given to remediation of point-source polluted sites with regard to potential health risks for children. However, because of diffuse pollution and long-range atmospheric deposition, soil contaminant levels are generally increased in urban areas compared to their rural counterparts, even in areas located away from any point sources of pollution. Intake of urban soil can thereby result in significant amounts of the child’s daily metal intake. In the present study, soil samples were collected from 25 playgrounds around urban Uppsala, Sweden and analysed for contents of Al, As, Fe, Cr, Cu, Cd, Hg, Mn, Ni, Pb, W and Zn. Prior to aqua regia digestion, the samples were wet-sieved in order to separate soil particle fractions representing deliberate (<4 mm) and involuntary (<50 μm) soil ingestion by children, as well as a third size fraction of 50–100 μm representing soil that is easily transported by suspension. While the metal and As contents in the 50–100 μm fraction were similar to those of the <4 mm fraction, the <50 μm fraction had metal and As contents on average one and a half times higher than those of the <4 mm fraction. The metal and As contents correlated negatively with the sand content in both particle size fractions <4 mm and 50–100 μm, suggesting a general decrease in metal and As content with increasing sand content. However, a positive correlation was found between sand content and the metal and As contents of the finest fraction (<50 μm), suggesting that when the sand content is high, the bulk of the sorbed elements are on the finest particles. The difference between metal and As contents in the different size fractions was greater in the soil sample with the highest sand content than in the sample with the lowest sand content. This implies that texture is a significant factor in metal and As distribution in soils with moderate metal and As contents, when the number of binding sites associated with small particles is low. Tolerable daily intake (TDI) values for Pb and As were exceeded at all sites, and at two sites for Cd, for children with pica behaviour. A high ingestion rate of mainly small particles could also result in the TDI value for Pb being exceeded at 10 sites and that for As at one site. This study also found that soil analysis by the procedure recommended by Swedish authorities accurately represents the metal intake from deliberate soil ingestion, whereas involuntary soil ingestion of mainly small particles could result in metal intakes which are up to twice as high. 相似文献
5.
Both linear and polynomial regression analysis techniques are used to assess the CIC (constant initial concentration) model of210Pb dating. Results obtained using published210Pb and porosity profiles in 12 freshwater sediment cores show that linear regression affords more reliable results. The polynomial regression, while capable of predicting the values of the constant or derived from porosity data, gives reasonable results only when all the coefficients of the polynomial are of appropriate sign. Lower values for all the parameters are obtained in all cases if the effect of compaction is not considered. 相似文献
6.
7.
The soil geochemical baseline is an important index in environmental assessment. Detailed baseline studies are necessary in large areas with complex geological settings, landforms and soil types. The Jianghan plain, a major industrial and agricultural region located in central China, has a soil geochemical baseline that has yet to be fully defined. The objective of this paper is to study the baseline of Cd, Pb and Zn in the topsoil of the Jianghan plain in a subarea using principal component regression (PCR). A total of 9030 samples were collected from the surface layer, and 2 soil profiles and 2 sedimentary columns were sampled near the Yangtze and Han rivers. Fifty-two elements and two parameters were analyzed. Data processing and the creation of spatial distribution maps of the elements were performed using MapGIS, R and SPSS software. The results show that the distributions of Cd, Pb and Zn are mainly controlled by parent material, drainage system and soil type. The study area is divided into 3 subareas, with factors reflecting the physico-chemical characteristics of the soil using factor analysis (FA). The geochemical baseline model is established in every subarea to predict the Cd, Pb and Zn values using principal component regression analysis (PCR); the exceptional values (as a result of anthropogenic input or mineralization) are distinguished by residuals (γ); and the natural background values and anthropogenic contributions are clearly distinguished. Therefore, the PCR method in these subareas is objective and reasonable, and the conclusion provides effective evidence of exceptional high values for further environmental assessment. 相似文献
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9.
土壤重金属含量是影响黄芩产量和质量的重要因素。选取承德市中部金沟屯和五道岭两处黄芩种植示范区为研究区,采集表层土壤样品355件,黄芩样品30件,重金属形态样品15件。在分析土壤Mn、Zn、Cu、Cr、Cd、As、Pb、Ni、Hg、V、Co、Sb和土壤有机质含量（SOM）及pH值,黄芩Zn、Cu、Cr、Co、Cd、Pb、Ni、Hg和As含量基础上,采用描述性统计、地累积指数、主成分和RDA分析、重金属生物富集系数、生物活性系数和迁移系数等方法论述了土壤-黄芩系统重金属生物有效性及迁移累积特征。结果表明:金沟屯和五道岭区土壤各重金属累积程度总体属无-中度累积水平。五道岭Cu和Hg累积程度高于金沟屯区,其它元素累积程度低于金沟屯区。五道岭区表层土壤Cr、Cu和Cd含量超标率分别为2.82%、1.69%和1.13%;金沟屯区土壤Cd、Cr和Ni,五道岭区土壤Zn和Hg含量超标率均为0.56%。五道岭区黄芩Cu元素含量高于金沟屯区,Co和Cu元素生物富集强度高于金沟屯区,其它元素含量和生物富集强度则均低于金沟屯区。土壤Cd和Hg元素生物活性系数相对最高,Ni、Zn和Pb元素次之,Cu、Cr和As生物活性系数相对较低。金沟屯区根系土具有较低的pH值和较高的SOM含量,区内黄芩根部As、Cd、Cr、Ni、Zn和Pb元素BCF平均值高于五道岭区,Cu元素富集强度低于五道岭区。土壤重金属生物有效性和黄芩重金属生物富集强度受土壤pH和SOM含量影响,其中Cd和Cu元素受SOM含量影响最为明显。 相似文献
10.
N. M. dos Santos C. W. A. do Nascimento V. S. de Souza Júnior R. J. Southard R. A. de Olinda 《International Journal of Environmental Science and Technology》2017,14(11):2331-2342
Todos os Santos (all Saints) Bay area on Brazil’s east coast is known for one of the most significant cases of lead contamination in the country owing to the past activities of a Pb-smelter plant. This work was carried out to assess the concentration and sources of Pb based on Pb isotopes and enrichment factor of soil profiles surrounding Todos os Santos Bay in order to understand the expansion of contamination and to help the establishment of Pb regulatory standards for the region. Forty-four samples were collected from soil genetic horizons of six pedons that represent the range of dominant soil properties and geologic materials in the region. Concentrations of Pb and the isotopes 204Pb, 206Pb, 207Pb, and 208Pb were determined on an inductively coupled plasma (quadrupole) mass spectrometry. The soil enrichment factor was calculated using Al and Fe as conservative index elements. Average Pb concentration (15.87 mg kg?1) in uppermost horizons (from all six pedons) is slightly higher than soil background concentrations commonly reported in Brazil. Samples feature a wide range of Pb isotope ratios, ranging from 36.71 to 47.38 for 208Pb/204Pb, 15.00 to 15.65 for 207Pb/204Pb, 16.86 to 20.59 for 206Pb/204Pb, and 1.10 to 1.31 for 206Pb/207Pb. For the enrichment factor calculations, only Fe demonstrated a good agreement with Pb isotopic ratios. Both Pb isotopic composition and enrichment factor were useful tools to distinguishing natural and anthropogenic influence on the Pb soil concentrations. 相似文献
11.
长春市土壤中Pb含量、化学形态和空间分布及其影响因素 总被引：3，自引：2，他引：3
以长春市7个功能区,30个采样点土壤为研究对象,研究城市土壤中Pb含量、化学形态与土壤物理化学性质的关系。结果发现:长春市土壤重金属Pb污染严重,主要以残渣态和有机结合态为主。不同功能区Pb含量及化学形态差别很大。土壤物理化学性质对Pb及各种化学形态含量影响程度明显不同,通过逐步回归方法确定主要影响因子,且建立土壤中Pb富集及其化学形态预测模型。 相似文献
12.
Lead has been exploited by man over thousands of years for a variety of metallurgical, medicinal, and industrial purposes. The cumulative output of Pb from mining is estimated to be 260 million metric tonnes and 85% of this has occurred over the last two centuries. Global annual production of Pb from mining was about 3 million tonnes at the turn of the millenium. Terrestrial ecosystems all over Norway have been contaminated moderately to strongly by Pb and other trace elements from atmospheric deposition. With the aim of developing a method for mapping the accumulated content of anthropogenic Pb and how deep in the soil profile the atmospherically deposited Pb has penetrated, the concentration of Pb and the 206Pb/207Pb ratio has been studied in podzolic forest soils at four locations with different lithology, i.e. age and type of bedrock, in the Oslo area. The concentrations of Pb in the soil profiles are 6.6–38.1 mg/kg (median 10.3). The 206Pb/207Pb ratio ranges between 1.168 and 1.314 (median 1.267) over the entire profile. In the upper 5 cm the range is 1.168–1.191, similar to ratios determined in recent atmospheric deposition. Applying three different methods, the amount of anthropogenically deposited Pb is estimated at 1–6 t/km2. 相似文献
13.
以广东省揭阳市土壤为研究对象,采集了表层土壤(0~20 cm)样1 330个和深层土壤(>150 cm)样331个,测定了土壤Pb含量。利用GIS空间分析技术、半变异函数拟合和方差分析等方法研究土壤Pb含量的空间结构、特征和影响因素。结果显示: 揭阳市不存在明显的土壤Pb污染,表层土壤Pb含量平均值39.26 mg/kg,低于揭阳市土壤Pb背景值(43.71 mg/kg),略高于广东省土壤Pb背景值(36.00 mg/kg);富集因子表明研究区表层土壤Pb富集程度主要为无富集和轻微富集,分别占52.11%和42.63%,Pb富集不明显;研究区表层土壤Pb空间分布呈中等自相关性;表层土壤Pb高值区主要分布在人类活动影响强烈的东部和南部地区。按土地利用、成土母质、土壤类型及其理化性质的分类统计表明,林地及未利用地表层土壤Pb含量最高;页岩风化形成的土壤Pb含量显著高于其他成土母质区土壤;黄壤Pb含量相对较高;有机碳和pH值均与土壤Pb含量呈显著正相关。 相似文献
14.
The contents of Pb, Cd, Cr, As, and Hg was investigated in the neighboring areas of a lead smelting enterprise and the metals contamination of soil was evaluated with the methodologies of the single factor index and Nemerow integrated index. It is found that the content of heavy metals in the neighboring areas has no obvious difference from the reference points. And the soil contamination of heavy metals varies by elements, the contamination index follows the pollution order： Cd〉Hg〉Cr〉As〉Pb. The pollution degree of Cd is at high level and Hg at low level, but Cr and As reached the warning level. Therefore, the lead smelting enterprises should not only control lead but also other heavy metals as Cd. 相似文献
15.
Roberto Wagner Lourenço Paulo M. Barbosa Landim André Henrique Rosa José Arnaldo F. Roveda Antonio César Germano Martins Leonardo Fernandes Fraceto 《Environmental Earth Sciences》2010,60(3):495-504
Spatial analysis and fuzzy classification techniques were used to estimate the spatial distributions of heavy metals in soil.
The work was applied to soils in a coastal region that is characterized by intense urban occupation and large numbers of different
industries. Concentrations of heavy metals were determined using geostatistical techniques and classes of risk were defined
using fuzzy classification. The resulting prediction mappings identify the locations of high concentrations of Pb, Zn, Ni,
and Cu in topsoils of the study area. The maps show that areas of high pollution of Ni and Cu are located at the northeast,
where there is a predominance of industrial and agricultural activities; Pb and Zn also occur in high concentrations in the
northeast, but the maps also show significant concentrations of Pb and Zn in other areas, mainly in the central and southeastern
parts, where there are urban leisure activities and trade centers. Maps were also prepared showing levels of pollution risk.
These maps show that (1) Cu presents a large pollution risk in the north–northwest, midwest, and southeast sectors, (2) Pb
represents a moderate risk in most areas, (3) Zn generally exhibits low risk, and (4) Ni represents either low risk or no
risk in the studied area. This study shows that combining geostatistics with fuzzy theory can provide results that offer insight
into risk assessment for environmental pollution. 相似文献
16.
宁沪高速公路句容段两侧土壤磁化率异常与重金属元素的关系研究 总被引：1，自引：0，他引：1
高速公路两侧土壤的磁化率从路中央向两侧具有逐渐降低的特征,相对应的样品中的重金属Cu、Pb、Zn、N i、Cr、Fe等元素的含量也具有从路中心向两侧逐渐降低的现象。相关分析表明,土壤磁化率与土壤中的Cu、Pb、Zn、N i、Cr、Fe的相关性显著,因而可以利用磁化率异常来指示高速公路两侧土壤的重金属污染状况。元素的赋存形态分析表明铁锰氧化物态与残渣态是Cu、Pb、Zn、N i、Cr、Fe的主要赋存形式;各元素的形态分析结果与土壤磁化率的相关统计分析表明,高速公路两侧土壤的磁化率与可交换态中的Cu、Pb、Zn、铁锰氧化物态中的Fe、Pb、Zn、有机还原态中的Cu、Cr、Fe、Zn和残渣态中的Cu、Pb、Zn、Cr、Co、N i具有明显的相关性。 相似文献
17.
Francisco Remonsellez Nicole Zarrias Roland Bol Bárbara Fuentes 《Environmental Earth Sciences》2017,76(7):294
Lead (Pb) dust exposure can have detrimental environmental and human health effects. Improperly enclosed stockpiles of Pb concentrates can cause dust emissions, subsequent pollution of the soil and environmental risk. The aim of this work was to study Pb form, distribution and immobilization (by using eggshell and seashell) in an industrial arid soil near a storage area of Pb mineral concentrates in northern Chile. High amounts of sulfur (S; 9900 mg kg?1) and Pb (6530 mg kg?1) were found in the polluted soil. The energy-dispersive X-ray spectroscopy analysis revealed a lead sulfide (PbS: galena). Metallic Pb particles, which were between 41 and 46 µm, were identified in the soil. After eggshell and seashell (20%) were applied, the soil pH increased from 6.0 to 7.84 and 8.07, respectively. In the studied soil, the leaching test showed a 59 mg L?1 average Pb extractable concentration. After 240 days, extractable Pb by toxicity characteristics leaching procedure decreased to 4.79 mg L?1 (93.3%) with the application of seashell at 20% compared with a decrease of 33.33 mg L?1 (53.6%) using eggshell. Pb in the polluted soil was mainly found in the exchangeable fraction (66%), followed by the reducible (24%), residual (7%) and oxidizable (6%) fractions. According to the risk assessment code, the contaminated soil before treatment was classified as very high risk. Adding eggshell (20%) and seashell (20%) decreased the exchangeable fractions to 39 and 35%, respectively. Applying these liming materials achieved Pb immobilization in the soil, but the soil remained in the high environmental risk category. We conclude that the application of seashell waste, resulting from high aquaculture activity, opens an interesting window to the treatment of contaminated arid soils. 相似文献
18.
Donald L. Suarez 《Geochimica et cosmochimica acta》1976,40(6):589-598
Soils of loamy sand on weathered, sandy dolomite were cored from six holes up to 70 ft beneath a municipal waste landfill in central Pennsylvania. Mn, Fe, Ni, Co, Cu, Zn, Cd, Pb, and Ag were determined in exchangeable and non-exchangeable forms in total and < 15 μm soil samples. Most of these metals were bound in Mn oxides, non-exchangeable with 0.5 M CaCl2. The Mn oxides (often X-ray amorphous) identified when crystalline as todorokite occurred chiefly as coatings on quartz grains.Somewhat higher amounts of acid leachable trace metals were found in the < 15 μm size fraction than in the total soil samples; however, trace metal/Mn ratios were similar in both. In general, the initial mild soil leaching, which dissolved chiefly Mn oxides, gave MnFeX>Co>Ni>Pb>Zn> Cu>Cd>Ag. The final leaching, which dissolved chiefly ferric oxides, gave Fe>Mn>Ni>Zn>Co> Cu>Pb>Cd>Ag. Samples taken from an unpolluted site and from the same soils affected for seven years by leachate from the refuse had similar metal contents.Soil extractable Co, Ni, Cu, and Zn could be predicted from the Mn extracted. Based in part on factor analysis of the data, Mn-rich oxides had at least tenfold higher heavy metal percentages than Fe-rich oxides (crystalline component goethite), reflecting their greater coprecipitation potential. Because of this potential and because of the generally higher solubility of Mn than Fe oxides, more heavy metals may be released from Mn-rich than from Fe-rich soils by disposal of organic-bearing wastes. However, leaching of the moisture-unsaturated soils in situ is rarely severe enough to completely dissolve both Mn and Fe oxides. Based on the Mn content, Cd, Cu, and Pb were depleted in soil moisture beneath the landfill relative to their amounts in the soil. This depletion may reflect factors including heterogeneity in metal content of the soil oxides; preferential resorption of these metals; and removal of the Cd, Cu, and Pb as organic precipitates or as inorganic precipitates such as carbonates. 相似文献
19.
新庄孜矿塌陷区煤矸石中重金属迁移对覆土影响 总被引：5，自引：0，他引：5
针对淮南新庄孜矿覆土造地中煤矸石填充带来的重金属元素迁移污染进行了研究。结果表明:煤矸石中有毒元素Pb、As、Cd、Hg向覆土有一定迁移,且距离煤矸石越近的土壤中重金属含量明显增高;虽然覆土中重金属含量均超过淮南土壤的均值,但是该土壤中Pb、As和Cd含量均符合国家二级标准;其中土壤中Hg含量分别符合国家一级标准和二级标准。须对覆土中重金属元素进行跟踪研究。 相似文献
20.
广西思旺地区位于钦杭成矿带西南端大瑶山金多金属成矿带上,1∶50 000水系沉积物测量成果表明该区Au、Ag、As、Hg、Sb、Pb、Cu、Sn、Mo、Bi等元素含量明显高于全国水系沉积物元素含量水平,Au、Ag、As、Pb、Cu、Sn、Bi、Mo等元素高于广西区背景含量;异常元素主要沿凭祥―大黎深大断裂两侧呈近EW和NE向带状展布。主要异常区均分布在凭祥―大黎深大断裂与近SN向断裂交汇处。根据异常特征与成矿地质条件,圈定了5个找矿远景区,为该区下一步找矿工作指明了方向。 相似文献