The distribution of metals from wastewater in the Mexican Valley of Mezquital

Since the beginning of this century, wastewater has been utilized for crop production in the Mexican Valley of Mezquital; however, few data are available for evaluating the level of heavy metal pollution in that region. Waters, soils and plants were sampled in different sites, representing three specific irrigation sources in the valley. Trace metals were determined in all samples. Total amount of most trace metals in raw municipal wastewater, and that of Ni, Cr, Pb and Zn in diluted water were quite high. Wastewater irrigation markedly increased the amounts of trace elements extracted from soils by 4M HNO₃; the amounts of metals were proportional to the amount of wastewater applied. Copper, chromium, and lead concentrations in soils roughly paralleled their organic matter contents. A wide range in tissue concentration of metals was observed. Zinc was the most metal absorbed by alfalfa and oats. Levels of Ni and Pb in plants, and to some extent, those of Co and Cu, were increased by raw wastewater irrigation. Chromium and lead accumulations in alfalfa were well above the tolerance levels suggested by some workers and the high Co concentration found in this legume may be a health risk for animals and human beings.     

Influence of prolonged use of sewage effluent in irrigation on heavy metal accumulation in soils and plants

Total content of Fe, Mn, Zn, Cu, Pb, Cd, Ni and Co in soils irrigated with sewage effluent increased with increasing years of using sewage effluent in irrigation. Iron and Co applied to the soil from sewage effluent were immobilized mainly in unavailable form; Pb, Cd, and Ni in moderately available form; and Mn, Zn, and Cu in highly available form. The concentrations of Fe, Mn, Zn and Cu in tops of alfalfa and leaves of corn grown on these soils increased substantially with increased levels of available metal content of the soil, while those of other metals were little affected. As for orange, continuous increase in leaves metal content with time was found for Fe, Mn, Zn, Co and Cd. The concentrations of Cd, Co, Ni and Pb in corn grains and orange fruits were several times higher than normal, and this reduces their suitability for human consumption.     

规模化猪场区域农田土壤重金属积累及影响评价分析

为了解长期灌溉猪场废水对农田土壤重金属的影响,采集了河北省京安猪场区域农田清洁区和灌溉8年猪场废水污灌区的耕层(0～20 cm)共52个土壤样品,并测定了样品的pH、养分和Zn、Cu、Cr、Ni、Pb和As全量和有效态含量,根据背景资料、相关分析和主成分分析确定重金属污染来源,应用富集因子分析重金属积累程度,并应用污染指数进行重金属影响评价分析。结果表明,灌溉猪场废水对土壤主要带来Zn和Cu的富集,对Ni、Cr和As几乎没有富集效应,Pb和As的富集主要由施用化肥引起。尽管灌溉8年猪场废水后土壤的Zn、Cu、Cr、Ni、Pb和As含量在安全范围内,但土壤重金属有效态含量不仅与重金属全量正相关,还与土壤pH负相关,而灌溉猪场废水会降低土壤pH,从而增加土壤重金属有效态含量。因此,长期灌溉猪场废水不但要注意土壤Zn和Cu积累,还需采取措施降低土壤Zn、Cu等重金属有效态含量以防重金属带来环境风险。     

Heavy Metals in Freshly Deposited Stream Sediments of Rivers Associated with Urbanisation of the Ganga Plain,India

Freshly deposited stream sediments from six urban centres of the Ganga Plain were collected and analysed for heavy metals to obtain a general scenery of sediment quality. The concentrations of heavy metals varied within a wide range for Cr (115–817), Mn (440–1 750), Fe (28 700–61 100), Co (11.7–29.0), Ni (35–538), Cu (33–1 204), Zn (90–1 974), Pb (14–856) and Cd (0.14–114.8) in mg kg^-1. Metal enrichment factors for the stream sediments were <1.5 for Mn, Fe and Co; 1.5–4.1 for Cr, Ni, Cu, Zn and Pb; and 34 for Cd. The anthropogenic source in metals concentrations contributes to 59% Cr, 49% Cu, 52% Zn, 51% Pb and 77% Cd. High positive correlation between concentrations of Cr/Ni, Cr/Cu, Cr/Zn, Ni/Zn, Ni/Cu, Cu/Zn, Cu/Cd, Cu/Pb, Fe/Co, Mn/Co, Zn/Cd, Zn/Pb and Cd/Pb indicate either their common urban origin or their common sink in the stream sediments. The binding capacity of selected metals to sediment carbon and sulphur decreases in order of Zn > Cu > Cr > Ni and Cu > Zn > Cr > Ni, respectively. Stream sediments from Lucknow, Kanpur, Delhi and Agra urban centres have been classified by the proposed Sediment Pollution Index as highly polluted to dangerous sediments. Heavy metal analysis in the <20-μm-fraction of stream sediments appears to be an adequate method for the environmental assessment of urbanisation activities on alluvial rivers. The present study reveals that urban centres act as sources of Cr, Ni, Cu, Zn, Pb and Cd and cause metallic sediment pollution in rivers of the Ganga Plain.     

海南岛土壤中若干元素的因子分析

本文用因子分析方法对海南岛土壤中若干元素的分布规律进行初步探讨.通过Q型分析表明,该地区土壤样品主要分成两大类.一类为富含铁族元素,另一类为铁族元素含量相对较低的.由R型分析结果表明,除铁族元素为一类外,易淋溶元素锶、抗风化元素锆分别各成一种类型.说明土壤中元素分布与成土母质类型和元素地球化学性质有关.     

Trace elements in surface soils from the mineralized area of Madison County, Missouri, U.S.A.

Duplicate, bulked surface soil samples, from sites 10m apart, were collected at 97 locations 1000 m apart on a regular grid measuring 8x11 km. Data were obtained for Ag, Ba, Be, Cd, Co, Cr, Cu, Li, Mn, Ni, Pb, V and Zn. One field sample was a good predictor of its nearby duplicate for Co, Cu, Ni and Pb, satisfactory for Ba, Be, Cr, Mn and Zn, but poorer for Cr, Li and V. Maps of the variation in precision of the field samples did not reveal any association between abandoned mine sites and high variability. The median coefficient of variation for trace elements in the field duplicates was between 8 and 19.5%. The duplicated field data were averaged to yield a mean soil metal concentration at each sample location. Concentrations of Ba, Be, Cr, Li, Sr and V were comparable with other published values for similar soils in Missouri. Concentrations of Co, Cu, Mn, Ni, Pb and Zn were higher which was explained by pollution from mining activities. A graphical technique was used to calculate background levels for metals in the second group. Samples of forest litter were collected at 12 locations: Ag, Ba, Cd, Mn, Sr and Zn concentrations were higher in the litter whereas Li and V concentrations were higher in the subjacent mineral soil. Computer isoline maps of the distribution of elements revealed an association between areas of high soil Cu, Co, Ni, Pb and Zn and abandoned mines or mineralized rocks.     

Die räumliche Variabilität von Schwermetall-Konzentrationen in Niederschlägen und Sickerwasser von Waldstandorten des Sollings

Local variability in the heavy metal concentrations of precipitation and seepage water from forest sites in the Solling Concentrations of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb in precipitation and seepage water have been measured continuously with local replicates during a 6-months period at a beech and a spruce forest site. Variation coefficients of the avarage concentrations were, in most cases, well below 30 %, being mainly caused by local differences. Comparison of means showed a significant increase of heavy metal concentration in the canopy drip of beech (Mn, Fe, Pb) and spruce (Cr, Mn, Fe, Ni, Zn, Pb) compared to bulk precipitation measured in the open field. Concentration of Mn, Co, Ni, Zn and Cd in the seepage water is significantly higher under spruce compared to beech. These results point at higher filter efficiency of the spruce canopy, compared with beech, for air pollutants, but a smaller retention capacity of the soil under spruce for heavy metals.     

长期污灌农田土壤重金属污染及潜在环境风险评价

以西安市某典型污灌区农田土壤为研究对象,分析长期污水灌溉对表层土壤重金属含量及富集状况的影响,采用内梅罗指数法和Hakanson潜在生态危害指数法对其污染现状及潜在环境风险进行评价。结果表明：长期污灌已导致农田土壤Cd、Cr、Cu、Hg、Ni、Pb和Zn7种重金属相对自然背景有不同程度累积,其富集比例依次为100%、82.69%、100%、100%、80.77%、98.08%和100%,仅有土壤As平均含量低于其背景水平;以国家土壤环境质量标准二级限量值作为污染评价阈值,其中Cd和Hg污染表现突出,按其污染指数平均值排序为Cd〉Hg〉Ni〉Cu〉Zn〉As〉Cr〉Pb;土壤重金属综合潜在环境风险为＂强＂等级,Hg、Cd的环境影响占据主导;随污灌年限增长,离灌渠越近,农田土壤重金属的污染水平和环境风险越高。鉴于该区土壤重金属已呈现较强生态危害性,应及时采取必要防治措施,调整土地利用结构,确保农田环境及农产品安全生产。     

浙江省永康城市土壤重金属元素富集特征

永康169个城市土壤X荧光光谱测试分析表明:Cu、Mn、Co、Fe、Cr、Pb、Ni、Ti八种重金属元素的平均含量超过金衢盆地土壤背景值,且以工业用地类样品的富集程度最高。永康城市土壤重金属污染水平呈整体较轻,局部严重态势;各重金属元素的离散程度均较大,Cu为强变异元素,变异系数为152.93%,其他元素也为中强变异,表明永康城市土壤重金属元素含量在研究区内有较大差异。多元统计分析表明,Cr、Ni、Cu、Pb、Mn等重金属元素主要来源于当地的五金制造等工业和交通运输的影响;Fe、Ti、Co来源主要与成土过程中元素的积累有关,其中Fe有部分来源于五金生产。     

东北及内蒙古东部的土壤微量元素

土壤中的微量元素在动植物生活中所起的重要作用日益被人们所重视.了解土壤中的这一部分资源对指导微量元素肥料的施用,从而达到农业增产以及对消除由土壤微量元素缺乏或过剩引起的某些动植物病害均具有重要的意义.探讨土壤微量元素在土壤剖面中的累积和迁移及其地理分布规律,则可进一步阐明土壤发生过程与生物地球化学特性的关系.     

新乡市大棚菜田土壤重金属积累特征及污染评价

采用微波消解-ICP-AES技术,测定不同种植年限大棚菜田土壤样品中As、Pb、Zn、Cd、Cr、Mn、Ni、Cu等重金属的含量,研究不同种植年限与大棚菜田土壤重金属累积的相关性以及大棚菜田土壤重金属累积特征,并利用地积累指数法进行污染评价。结果表明:大棚菜田土壤重金属Zn、Pb、Ni、Mn和Cu的含量与种植年限具有极显著相关性;大棚菜田土壤中重金属Cd和Cr的含量与种植年限不相关。重金属元素间相关性分析表明,Zn与Pb、Cd、Ni、Mn、Cr、Cu,Pb与Cd、Ni、Mn、Cr、Cu,Cd与Ni、Mn、Cr,Ni与Mn、Cr、Cu,Mn与Cr、Cu具有污染同源性,Cu与Cd、Cr不具有污染同源性。地积累指数法污染评价结果显示Cd的污染等级达到了6级,已构成了极严重污染;Zn和Cu的污染等级达到2级,已构成了中度污染;Pb、Mn的污染等级达到1级,已经构成了轻~中度污染;As、Ni、Cr均未构成污染。     

广东省土壤无机元素背景值的变化趋势研究

通过对“七五”期间广东省土壤环境背景监测点回顾性调查,以研究广东省土壤背景监测点13种无机元素含量变化趋势.与“七五”背景值对比,土壤A层中Hg以及A、C两层中F含量下降,其他11种元素含量均上升,特别是Se、V、Zn和Co的含量有较明显的上升.As、Co、Cr、F、Hg、Mn、Ni、V和Zn的含量从A层到C层呈增加趋势,Cd、Pb和Cu的含量呈减少趋势,Se的含量基本没有变化,此外还对无机元素含量变化的原因进行分析.     

宝鸡长青镇铅锌冶炼厂周边土壤重金属污染研究

通过野外采样和实验室分析,在分析土壤基本理化性质的基础上,重点研究宝鸡长青镇铅锌冶炼厂周边土壤中重金属元素的含量和形态特征,并进行了污染评价。结果表明,宝鸡长青镇铅锌冶炼厂周边土壤中Cu、Pb、Zn、Mn、Co、Ni、Cr的平均含量分别为31.8、41.3、102.6、704.6、14.4、37.4、83.2mg·kg-1,均高于陕西省和全国土壤元素背景值,尤其是Cu、Pb和Zn。土壤中Cu、Zn、Ni和Cr主要以残余态的形式存在,Pb、Mn和Co主要以可还原态和残余态的形式存在,重金属的迁移顺序为Mn（63.91%）〉Pb（60.08%）〉Co（51.70%）〉N（i37.12%）〉Zn（32.09%）〉C（r30.58%）〉Cu（19.95%）,其中,Mn、Pb和Co有50%~65%可以发生迁移,易被生物体利用,危害较大。评价结果表明,宝鸡长青镇铅锌冶炼厂周边土壤主要受到了Pb的轻度污染。     

不同高粱种质对污染土壤中重金属吸收的研究

利用重金属含量较高的污水污染土壤,以未污染土壤作对照,种植8个甜高粱品种、2个饲用高粱品种和1个粒用高粱品种,检测8种重金属在高粱植物体内不同器官的含量,以研究不同高粱种质对重金属的吸收特性。结果表明:甜高粱对汞(Hg)、镉(Cd)、锰(Mn)和锌(Zn)的吸收在两种土壤间差异显著,对钴(Co)、铬(Cr)、铅(Pb)和铜(Cu)的吸收差异不显著。Mn在甜高粱体内含量表现为未污染土壤高于污染土壤;而Zn含量在不同器官之间存在差异,未污染土壤叶中含量远高于穗,穗中含量远高于茎和根。不同重金属在甜高粱体内的储存部位不同,污染土壤上Hg、Cd、Co、Cr和Zn在根中积累量较高,Cu、Mn和Pb在穗中的积累量较高。甜高粱、饲用高粱和粒用高粱对重金属的吸收、运输及储存在品种之间差异较大,同一品种对不同重金属的吸收也存在差异。饲用高粱表现为叶部对Cr和Zn的储存量较高,而粒用高粱‘晋中0823’则显示了茎对多种重金属的储存能力。高粱根对土壤中重金属的富集系数较高,为0.02(Pb)~0.23(Cd),转移系数变幅为0.21(Co)~3.42(Pb)。对同一种重金属的吸收量品种间差异较大,甜高粱‘西蒙’根对Co、Cr、Cu、Mn、Pb和Zn具有高富集系数,粒用高粱‘晋中0823’茎对Hg、Cd、Mn、Pb和Zn富集系数较高。高粱对重金属的吸收能力与转移能力不同步,甜高粱‘绿能1号’具有对多种重金属的高转移能力,粒用高粱‘晋中0823’只对Zn有较高的转移能力。因此本文认为甜高粱对不同重金属的吸收和转移有选择性。对Zn吸收并转移到地上部后,首先储存在叶和穗中,当吸收量足够大时,茎和根也成为储存器官;对Mn的吸收与其他重金属的吸收存在竞争作用,Hg吸收后很少向地上部转移;而对Cu、Mn和Pb吸收后在穗部的储存量较大。饲用高粱与甜高粱相比对重金属的吸收未显示明显的不同,甜高粱‘西蒙’根对多种重金属具有强储存能力,而粒用高粱‘晋中0823’的茎秆显示了比甜高粱更强的储存能力,甜高粱‘绿能1号’对多种重金属的转移能力较强。所以,选择富集和转移能力均强的高粱品种能更有效地吸收土壤中的重金属,达到修复污染土壤的目的。     

宝鸡市某工业园区灰尘重金属含量、形态及生态风险分析

利用X射线荧光光谱法(XRF)和原子荧光分光光度法(AFS)分析了宝鸡市某工业园区灰尘中重金属的含量。结果表明,宝鸡市某工业园区灰尘中As,Co,Cr,Cu,Hg,Mn,Ni,Pb和Zn的平均含量分别为23.3,16.4,1 591.8,178.2,0.243,346.5,40.2,1 586.2和1 918.8mg/kg,其中,Cr,Cu,Hg,Pb和Zn累积比较明显;铅锌冶炼厂周边灰尘中As,Cu,Hg,Pb和Zn的含量高于电厂。采用修正BCR法(欧洲共同体标准物质局)和原子吸收分光光度法(AAS)研究了灰尘中重金属的形态特征。结果表明,灰尘中Cu主要以残渣态和可氧化态的形式存在,Pb主要以可还原态的形式存在,Zn主要以乙酸可提取态的形式存在,Mn和Co主要以乙酸可提取态和残渣态存在,Ni和Cr主要以残渣态存在。灰尘中Pb,Zn,Co,Mn和Cu有55%~85%可以发生移动,易被生物利用,危害较大。潜在生态风险评价表明,灰尘中重金属的污染及潜在生态风险达到严重水平,铅锌冶炼厂周边灰尘中重金属的污染和潜在生态风险高于电厂。     

杭州市城市土壤中重金属、磷和其它元素的特征

Health implications of inhaling and/or ingesting dust particles with high concentrations of heavy metals from urban soils are a subject of intense concern. Understanding the geochemistry of these metals is key to their effective management. Total concentrations of heavy metals, phosphorus (P) and 8 other elements from topsoil samples collected at 82 locations in Hangzhou City were measured to: a) assess their distribution in urban environments; and b) understand their differentiation as related to land use. Metal mobility was also studied using a three-step sequential chemical fractionation procedure. About 8.5%, 1.2%, 3.6%, 11.0% and 30.3% of the soil samples had Cd, Cr, Cu, Pb, and Zn concentrations, respectively, above their allowable limits for public and private green areas and residential use. However, in commercial and industrial areas, most samples had metal concentrations below their allowable limits. Statistical analyses revealed that the 16 measured elements in urban soils could be divided into four groups based on natural or anthropic sources using a hierarchical cluster analysis. Additionally, Cu, Pb, and P showed similar spatial distributions with significant pollution in commercial zones, suggesting vehicle traffic or commercial activities as dominant pollutant sources. Also, Cd, Co, Cr, Ni, Zn, Mn and Fe had the highest concentrations in industrial locations, signifying that industrial activities were the main sources of these seven metals. Moreover, the data highlighted land-use as a major influence on heavy metal concentrations and forms found in topsoils with large proportions of soil Cd, Co, Cr, and Ni found in residual fractions and soil Cu, Pb and Zn mainly as extractable fractions.     

Trace metal concentrations in borehole waters from the Upper Regions and the Accra Plains of Ghana

The concentrations of Hg, Cu, Pb, Zn, Cd, Fe, Mn, Cr and As were measured in groundwaters from the Upper West and Upper East Regions and the Accra Plains of Ghana. Apart from Fe, the trace metal levels for the two Upper Regions were similar. Samples from the Accra Plains had the highest trace metal concentration. However, Hg and As were undetected in all the samples. While the mean Cd, Mn and Cu concentrations for all the 3 study areas fell below the WHO limit, values for Pb and Cr exceeded the WHO limits for drinking water. Iron exceeded the limits in the Upper West Region and the Accra Plains. Overall, the most abundant elements in groundwaters were Zn, Fe and Cr.     

太原市污灌区土壤重金属污染现状评价

对太原市污灌区土壤重金属分布特征进行了分析评价,结果表明重金属Pb、Zn、Cu、Ni、Mn、Cr、As、Hg、Cd含量均值均未超过土壤环境质量标准（GB15618—1995）,但其平均值均显著高于太原市土壤背景值。各重金属间的相关分析表明,Pb、Zn、Cu、Ni、Mn、Cr、As、Cd之间呈极显著相关,说明这8种元素污染源可能相同。Hg是本区表层土壤重金属污染的主要因子,重金属元素的污染程度依次为Hg〉Cd〉Pb〉As〉Cu〉Zn〉Cr〉Mn〉Ni。土壤重金属单项污染指数均值均大于1,综合污染指数为2.81,总体上,污染水平为中度及其以上。各种重金属单因子污染指数和综合指数在研究区有相似的空间分布格局,总体分布趋势为东南部小店地区和中南部晋源区相对较高,南部清徐县相对较小;通过因子分析并结合污灌区污染源调查,表明Hg除受污水灌溉的影响外,燃煤释放的Hg可能是重要来源之一,Cd、Zn、Pb和Cu可能来自污水灌溉和大气沉降,以污水灌溉的贡献为主,Ni、Mn、As、Cr来自污水灌溉。Hg、Cd是太原市污灌区土壤中需要优先控制的重金属。     

Heavy Metals, Phosphorus and Some Other Elements in UrbanSoils of Hangzhou City, China

Health implications of inhaling and/or ingesting dust particles with high concentrations of heavy metals from urbansoils are a subject of intense concern. Understanding the geochemistry of these metals is key to their effective management. Total concentrations of heavy metals, phosphorus (P) and 8 other elements from topsoil samples collected at 82locations in Hangzhou City were measured to:a) assess their distribution in urban environments;and b) understand theirdifferentiation as related to land use. Metal mobility was also studied using a three-step sequential chemical fractionationprocedure. About 8.5%, 1.2%, 3.6%, 11.0% and 30.3% of the soil samples had Cd, Cr, Cu, Pb, and Zn concentrations,respectively, above their allowable limits for public and private green areas and residential use. However, in commercialand industrial areas, most samples had metal concentrations below their allowable limits. Statistical analyses revealedthat the 16 measured elements in urban soils could be divided into four groups based on natural or anthropic sourcesusing a hierarchical cluster analysis. Additionally, Cu, Pb, and P showed similar spatial distributions with significantpollution in commercial zones, suggesting vehicle traffic or commercial activities as dominant pollutant sources. Also, Cd,Co, Cr, Ni, Zn, Mn and Fe had the highest concentrations in industrial locations, signifying that industrial activities werethe main sources of these seven metals. Moreover, the data highlighted land-use as a major influence on heavy metalconcentrations and forms found in topsoils with large proportions of soil Cd, Co, Cr, and Ni found in residual fractionsand soil Cu, Pb and Zn mainly as extractable fractions.