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1.
东莞市农田土壤和蔬菜重金属含量分析(英文)   总被引:7,自引:1,他引:6  
A total of 118 of agricultural soil and 43 of vegetable samples were collected from Dongguan City,Guangdong,China. The spatial distribution,sources,accumulation charac-teristics and potential risk of heavy metals in the agricultural soils and vegetables were de-picted in details by three different approaches,including total contents of eight metal ele-ments in soils and vegetables,GIS maps and multivariate analysis of heavy metals in soils in the study. The results show that there are higher accumulation of heavy metals such as Cu,Zn,Ni,Pb,Cd and Hg in agricultural soils,and the contents of Pb (65.38 mg kg-1) and Hg (0.24 mg kg-1) are 1.82 and 2.82 times of the background contents of the corresponding heavy metals in soils of Guangdong Province,respectively. There are about 3.4% of Cu,5.9% of Ni,1.7% of Cd and 28% of Hg in all collected soil samples from all investigated sites which have overran the contents for heavy metals of the China Environmental Quality Standard for Soils (GB15618-1995,Grade Ⅱ ). The pollution characteristics of multi-metals in soils are mainly reflected by Hg. There are different sources to eight metal elements in soils,Cu,Zn,Ni,Cr and As are predominantly derived from parent materials,and Pb,Hg and Cd are affected by anthropogenic activities. The spatial distribution shows that the Cu,Zn,Ni,Cr,Pb,As and Hg contents of agricultural soils are high in the west and low in the east,and Cd contents are high in the northwest,southeast and low in the southwest in Dongguan. The ratios of vegetable samples which Ni,Pb and As concentrations higher than the Maximum Levels of Con-taminants in Foods (GB2762-2005) are 4.7%,16.3% and 48.8%,respectively. The order of bio-concentration factors (BCF) of heavy metals in vegetables is Cd Zn Cu As Ni Hg Cr Pb. It is necessary to focus on potential risk of heavy metals for food safety and hu-man's health from agricultural soils and vegetables in Dongguan City,Guangdong Province.  相似文献   

2.
A total of 118 of agricultural soil and 43 of vegetable samples were collected from Dongguan City, Guangdong, China. The spatial distribution, sources, accumulation characteristics and potential risk of heavy metals in the agricultural soils and vegetables were depicted in details by three different approaches, including total contents of eight metal elements in soils and vegetables, GIS maps and multivariate analysis of heavy metals in soils in the study. The results show that there are higher accumulation of heavy metals such as Cu, Zn, Ni, Pb, Cd and Hg in agricultural soils, and the contents of Pb (65.38 mg kg?1) and Hg (0.24 mg kg?1) are 1.82 and 2.82 times of the background contents of the corresponding heavy metals in soils of Guangdong Province, respectively. There are about 3.4% of Cu, 5.9% of Ni, 1.7% of Cd and 28% of Hg in all collected soil samples from all investigated sites which have overran the contents for heavy metals of the China Environmental Quality Standard for Soils (GB15618-1995, Grade Ⅱ). The pollution characteristics of multi-metals in soils are mainly reflected by Hg. There are different sources to eight metal elements in soils, Cu, Zn, Ni, Cr and As are predominantly derived from parent materials, and Pb, Hg and Cd are affected by anthropogenic activities. The spatial distribution shows that the Cu, Zn, Ni, Cr, Pb, As and Hg contents of agricultural soils are high in the west and low in the east, and Cd contents are high in the northwest, southeast and low in the southwest in Dongguan. The ratios of vegetable samples which Ni, Pb and As concentrations higher than the Maximum Levels of Contaminants in Foods (GB2762-2005) are 4.7%, 16.3% and 48.8%, respectively. The order of bio-concentration factors (BCF) of heavy metals in vegetables is Cd > Zn > Cu > As > Ni > Hg > Cr > Pb. It is necessary to focus on potential risk of heavy metals for food safety and human’s health from agricultural soils and vegetables in Dongguan City, Guangdong Province.  相似文献   

3.
湘江中下游农田土壤和蔬菜的重金属污染   总被引:11,自引:0,他引:11  
A total of 219 agricultural soil and 48 vegetable samples were collected from the midstream and downstream of the Xiangjiang River(the Hengyang-Changsha section)in Hunan Province.The accumulation characteristics,spatial distribution and potential risk of heavy metals in the agricultural soils and vegetables were depicted.There are higher accumulations of heavy metals such as As,Cd,Cu,Ni,Pb and Zn in agricultural soils,and the contents of Cd(2.44 mg kg^-1 ),Pb(65.00 mg kg^-1 )and Zn(144.13 mg kg^-1 )are 7.97,3.69 and 1.63 times the corresponding background contents in soils of Hunan Province,respectively. 13.2%of As,68.5%of Cd,2.7%of Cu,2.7%of Ni,8.7%of Pb and 15.1%of Zn in soil samples from the investigated sites exceeded the maximum allowable heavy metal contents in the China Environmental Quality Standard for Soils(GB15618-1995,Grade Ⅱ).The pollution characteristics of multi-metals in soils are mainly due to Cd.The contents of As,Cd,Cu,Pb and Zn in vegetable soils are significantly higher than the contents in paddy soils.95.8%, 68.8%,10.4%and 95.8%of vegetable samples exceeded the Maximum Levels of Contaminants in Foods(GB2762-2005)for As,Cd,Ni and Pb concentrations,respectively.There are significantly positive correlations between the concentrations of Cd,Pb and Zn in vegetables and the concentrations in the corresponding vegetable soils(p〈0.01).It is very necessary to focus on the potential risk of heavy metals for food safety and human health in agricultural soils and vegetables in the midstream and downstream of the Xiangjiang River,Hunan Province of China.  相似文献   

4.
With rapid economic and social development, soil contamination arising from heavy metals has become a serious problem in many parts of China. We collected a total of 445 samples(0–20 cm) at the nodes of a 2 km×2 km grid in surface soils of Rizhao city, and analyzed sources and risk pattern of 10 heavy metals(As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb and Zn). The combination of Multivariate statistics analysis and Geostatistical methods was applied to identify the sources and hazardous risk of heavy metals in soils. The result indicated that Cr, Ni, Co, Mn, Cu, and As were mainly controlled by parent materials and came from natural sources. Cd and Hg originated from anthropogenic sources. Pb and Zn, belonging to different groups in multivariate analysis, were associated with joint effect of parent materials and human inputs. Ordinary Kriging and Indicator Kriging suggested that single element and elements association from the same principal components had similar spatial distribution. Through comprehensive assessment on all elements, we also found the high risk areas were located in the populated urban areas and western study area, which could be attributed to the higher geological background in the western part and strong human interference in the eastern part.  相似文献   

5.
6.
Three kinds of tundra plant samples including Dicranum angustum(a type of boreal bryophyte),Puccinellia phryganodes(a type of fringy plant),Salix polaris(a type of vascular plant) and surface soil were samples in 200 at Ny-lesund of the Arctic.The levels of eight heavy metal elements(Hg,Pb,Cd,Cu,Zn,Ni,Fe and Mn) and three metal-like elements(As,Se,Sr) in the plant and soil samples of the areas within previous coal mining activities are significantly higher than those of other areas.The relative accumulation of these elements in these tundra plant samples is consistent with the one in the soil samples,especially in the areas affected by previous coal-mining activities.Thus,the pollution is apparently from local coal mining activity.Dicranum angustum has the highest concentrations among those elements,and it can be a good bio-indicator for heavy metal pollution in Ny-lesund.Though Ny-lesund is less polluted by heavy metal than nearby Northern European human living areas,but much more than the tundras of the Alaska,Greenland and the Antarctic.  相似文献   

7.
Groundwater is the most appropriate and widely used source of drinking water,which is increasingly threatened by pollution from industrial and agricultural activities.To check the severity of the problem,156 groundwater samples were collected from various depths(60-110 ft) of 52 different localities in Faisalabad city,the third largest metropolis in Pakistan,and analyzed for the metals(Zn,Cu,Cd,Ni,Pb,Mn and Fe) concentration in 2009.Quantification was done by using Flame Atomic Absorption Spectrophotometer technique and the results were compared with WHO standards for drinking water quality.Results showed that the levels of Cu,Mn and Fe were below the WHO standards while the concentrations of Zn,Cd,Ni and Pb were above the recommended levels of safe drinking water.Correlation analysis among the occurrence of these heavy metals revealed a highly significant and positive correlation of Mn with Zn and Fe.A significant and positive correlation of Cd was also found with Cu and groundwater depth showing that there is strong association between Cu-Cd pair and that the Cd concentration varies with depth of groundwater in the study area.Regional patterns of heavy metals occurrence were mapped using Geographical Information System(GIS) for the identification and demarcation of risk areas.The concentration maps may be used by policymakers of the city to mitigate groundwater pollution.  相似文献   

8.
上海市崇明岛农田土壤重金属的环境质量评价   总被引:21,自引:1,他引:20  
通过对上海市崇明岛28个菜地土壤表层样品、65个稻田土壤表层样品及9个西瓜地土壤表层样品的分析测试,利用国家、行业和地方的相关标准评价了农田土壤重金属(Pb、Cd、Cr、As、Hg)的环境质量状况.研究发现:崇明岛农田土壤重金属的总体含量为Pb21.597 mg·kg-1、Cd 0.176 mg-kg-1、Cr 69.395 mg·kg-1、As 9.209 mg·kg-1、Hg O.128 mg·kg-1.与上海市土壤背景值相比,除Pb、Cr外,其余重金属平均含量均高于其背景值,Cd、As和Hg分别高出背景值33.O%、1.2%和26.3%.在GIS软件支持下,通过空间插值分析了研究区农田土壤重金属含量的空间分布特征,结果发现,农田土壤质量整体尚好,土壤生态率为1.26%,优良率为97.14%,合格率为1.47%,不合格率为0.12%.以背景值为标准,崇明岛农田土壤Pb、Cd、Cr、As、Hg的超标率分别为10.1%、85.7%、27.0%、55.4%、55.2%;3种土地利用类型中,菜地受重金属污染最为严重,这主要与菜地施用更多农药有关.崇明岛重金属的年沉降通量分别为Pb 7735.470 ug·m-2.a-1、Cd 208.432ug.m-2·a-1、As 2237.738 ug·m-2·a-1、Hg 52.783 ug·m-2·a-1,农作物秸秆焚烧处理是崇明岛大气重金属沉降的重要来源,大气沉降对崇明岛农田土壤重金属有较大的影响.  相似文献   

9.
澜沧江-湄公河重金属污染评价及大坝影响(英文)   总被引:1,自引:1,他引:0  
The resource development and changes of hydrological regime,sediment and water quality in the Mekong River basin have attracted great attentions.This research aimed to enhance the study on transboundary pollution of heavy metals in this international river.In this study,eight sampling sites were selected to collect the bed sand samples along the mainstream of the Mekong River.In addition,the contents of 5 heavy metal elements and their spatial variability along the mainstream of the river were analyzed.The geoaccumulation index(I geo) and potential ecological risk analysis were employed to assess heavy metal pollution status in the mainstream of the Mekong River.The results show that the average content of the heavy metal elements Zn is 91.43 mg/kg,Pb is 41.85 mg/kg,and As is 21.84 mg/kg in the bed sands of the Upper Mekong River,which are higher than those(Zn 68.17 mg/kg,Pb 28.22 mg/kg,As 14.97 mg/kg) in the Lower Mekong.The average content of Cr in the Lower Mekong is 418.86 mg/kg,higher than that in the Upper Mekong(42.19 mg/kg).Luang Prabang has a very high Cr concentration with 762.93 mg/kg and Pakse with 422.90 mg/kg.The concentration of Cu in all of the 8 sampling sites is similar,except for in Jiajiu with 11.70 mg/kg and Jiebei with 7.00 mg/kg.The results of the geoaccumulation index reveal that contaminations caused by Zn and Pb while Pb and As are more than those by Zn in Upper Mekong.Cr is the primary pollutant in the Lower Mekong,especially at Luang Prabang and Pakse.Slight pollution with As also occurs in Pakse.The potential ecological risk index indicates that the potential ecological risk of heavy metals in the mainstream of the Mekong River is low.We argue that the pollution of water quality and contamination of heavy metals in bed sediment caused by mining of mineral resources or geochemical background values in the Mekong is not transmitted from the Upper to the Lower Mekong because of the reservoir sedimentation and dilution along the river.  相似文献   

10.
The spatial distributions of lead, arsenic, and copper(Pb, As, and Cu, respectively) in surface snow along the transect from the Zhongshan Station to Dome A, East Antarctica, are presented. The mean concentrations of Pb, As, and Cu are1.04±1.56 pg/g, 0.39±0.08 pg/g, and 11.2±14.4 pg/g, respectively. It is estimated that anthropogenic contributions are dominant for Pb, As, and Cu. Spatially, Pb concentrations show an exponentially decreasing trend from the coast inland, while a moderate decreasing trend is observed for Cu concentrations in the coastal area(below 2,000 m above sea level(a.s.l.)).In the intermediate area(2,000–3,000 m a.s.l.), the concentrations and enrichment factors of all these elements show high variability due to the complicated characteristics of climate and environment. On the inland plateau(above 3,000 m a.s.l.),the high concentrations of As and Pb are induced by high deposition efficiency, the existence of polar stratospheric precipitation, and the different fraction deposition to East Antarctica. The extremely high concentrations with maximum values of9.59 pg/g and 69.9 pg/g for Pb and Cu, respectively, are suggested to result mainly from local human activities at the station. Our results suggest that source, transport pathway, and deposition pattern, rather than distance from the coast or altitude, lead to the spatial distributions of Pb, As, and Cu; and it is further confirmed by spatial variations of the three metals deposited over the whole continent of Antarctica.  相似文献   

11.
The environmental quality of heavy metals (Pb, Cd, Cr, As, Hg) in agricultural surface soil of Chongming Island was assessed by national, local and professional standards based on a large scale investigation, in which 28 samples from vegetable plots, 65 samples from paddy fields and 9 samples from watermelon fields were collected from whole island area. Results showed that the average concentration of Pb, Cd, Cr, As and Hg was 21.6 mg·kg-1 , 0.176 mg·kg-1, 69.4 mg·kg-1, 9.209 mg·kg-1 and 0.128 mg·kg-1, respectively. Compared with the background value of Shanghai City soil, except for Pb and Cr, all the other heavy metals average concentrations in Chongming Island agricultural surface soil exceeded their corresponding natural-background values. The concentrations of Cd, As and Hg were 33.0%, 1.2% and 26.3% higher than the background value of Shanghai City, respectively. In addition, inverse distance interpolation (IDW) tool of GIS was also applied to study the spatial variation of heavy metals. The results indicated that most of agricultural soil quality was good, and the ratio of ecological, good soil, certified soil and disqualified soil were 1.26%, 97.1%, 1.47% and 0.12%, respectively. About 10.1%, 85.7%, 27.0%, 55.4% and 55.2% soil samples exceeded the Pb, Cd, Cr, As and Hg background value of Shanghai City, respectively. Among these three land use type soils, vegetable soil was most seriously polluted by heavy metals, which is probably related to the over-application of pesticides. The annual deposition fluxes of Pb, Cd, As and Hg were 7736 μg·m-2·a-1, 208 μg·m-2·a-1, 2238 μg·m-2·a-1 and 52.8 μg·m-2·a-1, respectively. Crop straw burning was the important source of heavy metals of atmospheric deposition, and atmospheric deposition contributed a lot to heavy metals in agricultural soil in Chongming Island.  相似文献   

12.
东莞市农田土壤和蔬菜重金属的含量特征分析   总被引:28,自引:1,他引:27  
从东莞市采集118 个农田土壤样品和43 个蔬菜样品, 测试其中Cu、Zn、Ni、Cr、Pb、 Cd、As 和Hg 等8 种重金属元素的含量, 并结合GIS 制图和数据统计, 对农田土壤中重金属 的空间分布和来源、土壤和蔬菜中重金属的富集特征及其潜在风险进行了分析。结果表明, 农田土壤中Cu、Zn、Ni、Pb、Cd 和Hg 等元素含量均高于相应元素的广东省土壤背景值, 其中, Pb (65.38 mg kg-1) 和Hg (0.24 mg kg-1) 含量分别为其对应背景值的1.82 和2.82 倍。与我国《土壤环境质量标准》中II 级标准(pH < 6.5) 相比, 土壤中Cu、Ni、Cd 和Hg 含量样本超标率分别为3.4%、5.9%、1.7%和28%, 表现为以Hg 为主的多种重金属共同污染。土壤 中8 种重金属中Cu、Zn、Ni、Cr 和As 等元素主要来源于成土母质, Pb、Hg 和Cd 等元素主要与人类活动有关。空间分布上, Cu、Zn、Ni、Cr、Pb、As 和Hg 等7 种重金属含量呈现出西部高、东部低的特点, Cd 含量在西北部和东南部较高, 西南部较低。与《食品中污染物限量》(GB2762-2005) 等相关标准比较, 蔬菜中Ni、Pb 和As 含量的样本超标率分别为4.7%、16.3%和48.8%。蔬菜中重金属富集系数的顺序为: Cd > Zn > Cu > As > Ni > Hg > Cr > Pb。  相似文献   

13.
Concentrations of heavy metals (Cu, Pb, Zn, Cr and Cd), and phosphorous (P) were determined in surface tidal flat sediments of the Yangtze estuary and Shanghai coast. Results demonstrate that there were significant differences among the accumulation of the heavy metals in sediments, following the order: Zn > Cu > Cr > Pb > Cd. The spatial distribution and chemical forms of heavy metals in tidal flat sediments were closely related to the distribution of pollution resources (outlet of sewage) and the local sedimentary and hydrodynamic conditions. The dominated form of non-residual heavy metals is bound to Fe/Mn oxides, and the next form is bound to carbonates. Moreover, contents of total P in sediments range from 18.0 μmol.g−1 to 31.4 μmol.g−1 along the coastline, speciation of P in sediments was different, most of P in tidal flat sediments is associated with calcium phases (as Ca-P) similar to marine sediments.  相似文献   

14.
黄河下游滩区开封段土壤重金属空间分异规律   总被引:5,自引:0,他引:5  
对黄河下游滩区开封段及滩外土壤采样48个,按照土壤化学分析方法,对铅(Pb)、铬(Cr)、汞(Hg)、砷(As)和镉(Cd)5种重金属进行分析,采用单因子污染指数、普通克里格法和相关分析对研究区土壤重金属含量特征、污染状况和分布特征进行了计算。结果表明:①研究区土壤5种重金属Pb、Cr、Hg、As和Cd含量就平均值而言,Cr的平均含量最大,Pb、Hg的平均含量最小。Pb、Cr、Hg、As和Cd4种重金属元素的变异系数在0.13~0.28之间,属于中等变异强度,Hg变异系数较大,Hg的空间差异相对较大;②重金属元素Pb、Cr、Hg、As、Cd之间具有较强的线性关系,可能具有共同来源——水沙输入;③主要污染元素为Hg、As、Pb,其中Pb的污染为中度污染且范围较广,而As和汞Hg构成三级轻度污染。Cr和Cd在各村间变化不大,Cr,Cd没有构成污染,且Cd是全部清洁表现出污染没有积累;④土壤各重金属元素的空间分布特征在研究区内上下段之间分异明显,上段呈清洁状态,中段有少量污染,下段表现出明显富集的分布状态。  相似文献   

15.
Recent heavy metal accumulation in Dongjiu and Xijiu lakes,East China   总被引:3,自引:0,他引:3  
Taihu Lake has been recognized as a seriously contaminated waterbody with regard to Cd, Cu, Pb and Zn over the last two decades. The input of pollutants has increased due to economic and social development and population increase. Seventy percent of the pollutants in Taihu Lake comes from rivers, with the Yili River being a major source of pollutants. Lakes Xijiu and Dongjiu are connected to the Yili River and Taihu Lake and are sites where material is preferentially deposited because of hydrodynamic conditions. Sediment cores were collected from Xijiu Lake (core XJ-1) and Dongjiu Lake (core DJ-5) to investigate anthropogenic heavy metal contamination. Concentrations of Cu, Pb and Zn gradually increased since the late 1930s, peaked in 1970, and then dropped slightly. A sudden increase in concentrations of Cu, Pb and Zn occurred in 1991 and peaked again in 1996, then dropped markedly. Maximum concentration of Cd in core XJ-1 was 21.2 mg kg−1 and mean concentration was 12.1 mg kg−1. In core DJ-5, the maximum and mean concentrations were 6.9 and 5.4 mg kg−1, respectively. Cr showed a pattern of variation different from the other heavy metals, but its concentration also dropped after peaking in 1996. Enrichment factors and anthropogenic factors revealed that human activities in the catchment played a key role in the heavy metal contamination. Increases in Cd, Cu, Pb and Zn concentration were caused by industrial development, particularly from non-ferrous metal smelting industries. The recent drop in Cd, Cu, Pb and Zn concentrations is attributed to pollution reduction measures instituted by the government. Cr was influenced by both natural and anthropogenic processes.  相似文献   

16.
通过田间试验和室内分析相结合,对兰州市蔬菜和土壤中重金属cd、Hg、Pb、As和cr的含量进行测定并评估经食入途径对人体的健康风险,同时运用改进的物元模型综合评价兰州市三县四区土壤重金属污染并进行分区。结果表明:(1)兰州市菜地土壤中Cd、Hg、Pb、As和cr的平均含量都高于背景值,存在明显的积累,但均低于《土壤环境...  相似文献   

17.
钱翌  于洪  王灵 《干旱区地理》2013,36(2):303-310
利用地理信息系统(GIS)及地统计学方法,对乌鲁木齐米东区农田土壤中重金属(Hg、Cu、Zn、Pb、Ni、Cd及Cr)的含量进行空间变异性分析。结果表明:除Cu、Zn、Pb和Hg超过土壤背景值外,7种重金属的平均含量均未超过国家环境质量二级标准(GB15618-1995);7种重金属均具有较好的空间变异结构,可以用指数模型、球状模型和高斯模型拟合,且具有不同程度的块金效应;Cd、Cr具有强烈的空间自相关性,Pb、Ni、Cu、Zn和Hg属中等强度空间相关, 说明其含量受外源污染的影响较大;采用普通克里格插值法得出7种重金属的空间分布图,除Cd空间分布规律不明显外,其它6种重金属均存在显著的空间分布规律。  相似文献   

18.
太仓市表层土壤Zn、Cu属强变异强度,呈对数正态分布;Cd、Ni、Hg、As、Cr和Pb属中等变异强度,呈正态分布。Cu、Hg、Zn、As显著高于当地背景值,以As累积指数和超背景值率最高;8种重金属除As自表层向下递增外,其余元素均为表层向下递减。土壤复合污染严重,土壤潜在生态风险达中等水平,黄泥土生态风险高于沙夹垅;重金属生态风险以印染厂最大,其次为电镀厂和养殖场,产生潜在生态风险为Hg、Cd,而As、Cu、Zn、Cr、Ni、Pb等多属轻微水平。  相似文献   

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