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1.
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   

2.
以江苏昆山市为典型区,对长三角地区土壤盐酸可提取态重金属含量的结构特征进行分析,得出该区盐酸可提取态重金属的空间分布格局并揭示了引起这种分布格局的成因和污染来源,结果表明:昆山市盐酸可提取态Cd、Cr、Cu、Pb、Zn、Hg属强变异,Ni和Co为中等变异。半方差函数模型拟合表明所有盐酸可提取态重金属元素均符合球状模型,8种重金属元素在一定范围内均存在空间相关性。采用Kriging最优内插法得到了盐酸可提取态重金属含量的空间分布格局,表明土壤盐酸可提取态重金属含量与工业活动、污水灌溉和大气降尘密切相关。通过主成分分析与地统计学相结合的方法,得出该区盐酸可提取态重金属由4个主成分构成,第一主成分为Cd、Cu、Pb、Cr和Zn,决定这一成分的主要因素为工业污水灌溉、大气降尘和元素地球化学特征;第二主成分为Ni,决定这一成分的主要因素为土壤内部因子;第三主成分为Hg,该成分主要受工业点源污染的影响;第四主成分为Co,该成分可能主要受地形影响。  相似文献   

3.
贵阳市城区土壤重金属分布特征及污染评价   总被引:12,自引:0,他引:12  
王济  张浩  曾希柏  白玲玉 《土壤》2010,42(6):928-934
调查了贵阳市不同功能区表层土壤中重金属含量及其分布特征,以基线为参比值,采用Hakanson潜在生态危害指数法对重金属的潜在生态风险进行了评价。结果表明,贵阳市城区土壤重金属(Hg、Cd、As、Pb、Cr、Cu、Ni、Zn)主要来源于工业、交通以及燃煤等活动,其平均含量分别为0.108、0.320、20.53、22.17、35.71、64.87、48.65、217.90mg/kg,除Cr外,均显著高于相应基线。工矿区土壤中Pb、Zn含量显著高于其他功能区(p0.05)。Hg和Cd是主要的生态危害因子,其污染已达强生态危害水平,其余均显示为轻微生态危害水平;不同功能区土壤重金属污染均已达强生态危害水平,且污染程度依次是:商务区工矿区文教区居民区城市绿地交通区。  相似文献   

4.
博斯腾湖湿地边缘带农田土壤重金属的污染风险评价   总被引:2,自引:0,他引:2  
对新疆博斯腾湖湿地边缘带农田土壤中8种重金属元素(As、Cd、Cr、Cu、Mn、Ni、Pb和Zn)地球化学特征进行分析。采用污染负荷指数(PLI)、潜在生态风险指数(RI)和生态风险预警指数(IER)对农田土壤重金属污染与环境风险进行评价。结果表明:(1)湿地边缘带农田土壤Pb和Zn呈现重度污染,As、Cd、Cr和Ni轻度污染,Cu轻微污染,Mn无污染。土壤As、Cd、Cr、Cu、Ni、Pb和Zn平均含量处于轻微风险水平。Cd是污染程度与生态风险等级最高的重金属元素;(2)湿地边缘带农田土壤PLI平均值为1.43,呈现轻度污染,RI平均值为20.62,呈现轻微生态风险状态,IER的平均值为–4.53,呈现无警态势。湿地边缘带PLI、RI与IER空间分布格局基本一致;(3)湿地边缘带农田土壤Pb与Zn来源主要受到人类活动的影响,Cr、Cu、Mn与Ni来源主要受到土壤地球化学作用的控制,As与Cd受自然因素和人为因素共同影响。  相似文献   

5.
城市化、工业化和农业集约化的发展影响着土壤环境和健康质量。本研究以位于长江三角洲地区的江苏省太仓市为典型区,采用地统计学方法对其耕层土壤中Cd、Cr、Cu、M、Hg、Pb、Zn和As等8种重金属结构特征和空间分布格局进行了分析,并用模糊数学法综合评价了土壤重金属的污染程度,结果表明: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。除Cd、Cr和Pb略低于背景值外,其他重金属均高于其背景值,其中以As污染指数和超标率最高。土壤重金属复合污染严重,模糊综合评价污染结果为一级。通过半方差函数模型拟合发现Hg、Cd符合球状模型,其他重金属均符合指数模型,8种重金属元素在一定范围内均存在空间相关性。采用Kriging最优内插法得到了耕层土壤重金属含量的空间分布图,发现土壤重金属含量与母质、土壤质地、有机质含量以及工业化、城市化和农业集约化程度密切相关。  相似文献   

6.
中国太原市农业土壤的重金属污染状况   总被引:5,自引:0,他引:5  
To evaluate the current state of the environmental quality of agricultural soils in Taiyuan City, a hotspot for China’s industrial development, the concentrations of 8 heavy metals in soils were investigated by means of extensive sampling in farmlands, forestlands, and grasslands in the city. Statistical analyses and spatial distribution maps were used to identify the most significant heavy metal pollutants. The mean concentrations of As, Cd, Cu, Hg, Pb, Zn, Ni, and Cr were slightly higher than their background values in Taiyuan’s topsoil, but were lower than the maximum permissible concentrations in the Chinese Environmental Quality Standard for agricultural soils. Farmland soils in Taiyuan had the highest average Cd, Cu, Hg, Pb, Zn, and Cr concentrations, but the As and Ni concentrations did not differ significantly among the farmland, forestland, and grasslands. Soil contamination by Cd, Cu, Hg, Pb, Zn, and Cr was mainly derived from farming practices, especially the use of sewage water for irrigation. In contrast, As and Ni might derive mainly from the soil parent material. The identification of heavy metal sources in agricultural soils may provide a basis for taking appropriate action to protect soil quality.  相似文献   

7.
A total of 50 farmland soil samples were collected from the Yanqi County, Xinjiang, China, and the concentrations of eight heavy metal elements (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn) were determined by standard methods. The spatial distribution, pollution level and ecological risk status of heavy metals were analyzed based on GIS technology, the Geo-accumulation Index (Igeo), the Pollution Load Index (PLI) and the Potential Ecological Risk Index (RI). Results indicated that: (1) The average contents of Cd, Cr, Ni, Pb, and Zn of farmland soils exceeded the background values of irrigation soils in Xinjiang by 1.5, 1.40, 1.33, 2.63, and 4.92 times, respectively. Cd showed a no-pollution level, Zn showed a partially moderate pollution level, Pb showed a slight pollution level, and Cr, Cu, As, Mn, and Ni showed no-pollution level, compared to the classification standard. The PLI values of heavy metal elements of farmland soils varied from 0.83 to 1.89, with an average value of 1.29, at the moderate pollution level. (2) The Individual Potential Ecological Risk Index for heavy metals in the study area was ranked in the order of: As > Ni > Cu > Cd > Pb > Cr> Zn. The RI values of heavy metals of farmland soils varied from 3.45 to 11.34, with an average value of 6.13, at the low ecological risk level. (3) Cu and Mn of farmland soils were mainly originated from the soil parent material and topography of the study area. As, Cd, Ni and Pb were mainly originated from human activities, and Cr and Zn may originated from both natural and anthropogenic factors in the study area.  相似文献   

8.
Phosphorus (P) is necessary for growth and nitrogen fixation, and thus its deficiency is a major factor limiting legume production in most agricultural soils. The effect of phosphorus supply on nodule development and its role in soybeans (Glycine max L.) was studied in a nutrient solution. Plants were inoculated with Bradyrhizobium japonicum and grown for 35 days in a glasshouse at a day and night temperature of 25℃ and 15℃, respectively. Although increasing P supply increased the concentrations of P and N in the shoots and roots, the external P supply did not significantly affect the P concentration in the nodules, and the N fixed per unit nodule biomass decreased with increasing P supply. The nitrogen content in the shoots correlated well with the P content (r=0.92**). At an inoculation level of 10^2 cells mL^-1, the P supply did not affect the number of nodules; however, at inoculation levels of 10^3.5 and 10^5 cells mL^-1, increasing P supply increased both the number and size of nodules. Irrespective of the inoculation level, increasing P supply increased the nodule biomass relative to the biomass of the host plant. It is suggested that the P deficiency specifically inhibited the nodule development and thereby the total N2 fixation.  相似文献   

9.
【目的】加强高速公路沿线土壤重金属污染管控及农业安全生产,亟需明确高速公路周边土壤重金属的分布特征与影响因素。【方法】选择贯穿江苏省境内的4条典型高速公路(沪宁、京沪、宁通和连霍)周边土壤为研究对象,利用高精度X射线荧光光谱仪(XRF)测定土壤重金属含量,从而分析高速公路沿线土壤重金属的空间分布特征,并探究其主要影响因素。【结果】(1)高速公路沿线表层土壤镉(Cd)、铅(Pb)、铜(Cu)、锌(Zn)含量总体呈南高北低、南北向公路小于东西向公路的分布特征,部分点位土壤Cd存在超标现象;(2)距公路路肩距离是影响两侧土壤重金属含量的重要因素,主要影响范围在50 m内,不同土地利用类型条件下土壤金属含量差异较大,路龄越长,土壤重金属富集系数越大。【结论】高速公路沿线表层土壤均存在重金属累积现象,其中Cd的累积最为明显,深层土壤重金属受到公路交通的影响较小。公路交通对沿线土壤重金属含量的影响主要在50 m以内,并且受到沿线土地利用类型、路龄和车流量的共同影响。在高速公路两侧设置不同范围的绿化带种植防护林,可在一定程度上防控重金属向周边农田的扩散与风险。  相似文献   

10.
采用盆栽试验方法研究了不同盐分含量处理下番茄不同器官盐分离子(Na+、K+、Ca2+)和重金属离子(Cd2+、Pb2+、Cr2+、Zn2+、Cu2+、Ni2+)的分布特征,探讨盐分离子对番茄不同器官吸收重金属离子的影响机制,为重金属污染盐渍土壤的农业可利用性评价提供科学依据。结果表明,番茄根、茎、叶和果实Na+含量均随盐分含量增加而增加;番茄根K+含量随盐分含量增加小幅上升,茎K+含量则显著下降,叶K+含量无显著变化;番茄各器官Ca2+含量随盐分含量增加无明显变化。番茄根Cd、Pb、Cr、Zn和Cu含量以及番茄茎、叶Cd含量均随盐分含量增加而增加;番茄根Ni含量、番茄茎叶Pb、Cr、Ni、Zn和Cu含量以及番茄果实各重金属含量受盐分含量变化影响不大。因此,土壤盐分含量的增加对番茄根部吸收重金属(Ni除外)有促进作用。  相似文献   

11.
为了解浙江龙游硫铁矿区农田重金属污染状况,采集矿区265件农田土壤样品,分析8种重金属Cu、As、Hg、Zn、Cd、Ni、Pb、Cr元素全量,利用地统计学软件GS+9.0对研究区土壤各元素指标进行半变异函数拟合,并利用普通克里格法进行插值并绘制空间分布图。采集30件水稻籽粒样品,分析重金属在研究区中水稻籽粒的累积特征,并进行了健康风险评价。结果表明:矿区土壤中8种重金属元素的变异系数从0.72到1.76,离散程度较高。8种重金属的土壤空间半变异函数Cu、As、Hg元素符合指数模型,Zn、Cd、Ni、Pb符合球状模型,Cr符合高斯模型。元素Cu、Pb、Zn、Cr、Ni的块金值与基台值的比值C0/C0+C都小于0.25,说明空间变化主要受地质背景等因素影响;元素Cd、Hg和As的块金值与基台值的比值C0/C0+C在0.25~0.75之间,说明除了地质背景因素,人为活动等随机因素也有影响。矿区水稻籽粒中重金属Ni和Cd的变异系数最高,分别为0.95和0.87,说明Ni和Cd元素可能存在异常积累。矿区水稻籽粒对重金属的富集能力由大到小依次为Cd、Zn、Cu、Ni、As、Hg、Cr、Pb。健康风险评价结果表明矿区农田水稻籽粒中元素As、Cd的风险商大于1,存在潜在健康风险;而其他6种重金属Cu、Hg、Zn、Ni、Pb和Cr基本属于安全范围。  相似文献   

12.
双城市土壤重金属空间分异及影响因子分析   总被引:13,自引:1,他引:13  
采用地理信息系统(GIS)和地统计学相结合的方法,研究了黑龙江省双城市的土壤全量铜、锌、铅、镍、镉5种重金属元素的空间分异规律及其影响因子。结果表明:研究区土壤锌、镍、镉具有强烈的空间相关性,表明这3种元素受土壤内在属性影响较大;而铜、铅具有中等强度的空间相关性,表明这2种元素由土壤内在属性和人为因素共同起作用。镉、铅、铜较锌、镍的变程小,说明前3种重金属元素含量可能主要受到较小尺度因子的影响。研究区土壤各重金属元素空间分异规律如下:铜和镍呈东高西低的趋势,铅呈南高北低的趋势,而锌和镉分别表现为块状分布和岛状分布的特点。影响重金属元素空间分布的影响因子主要有自然因素(土壤类型、高程、土壤理化性质等)和人为因素(乡镇、道路、各种工厂等)。  相似文献   

13.
The objective of this study was to test the suitability of a simple approach to identify the direction from where airborne heavy metals reach the study area as indication of their sources. We examined the distribution of heavy metals in soil profiles and along differently exposed transects. Samples were taken from 10 soils derived from the same parent material along N-, S-, and SE-exposed transects at 0—10, 10—20, and 20—40 cm depth and analyzed for total Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn concentrations. The heavy metal concentrations at 0—10 cm were larger than background concentrations in German arable soils except for Cr (Cd: 0.6—1.8 mg kg—1; Cr: 39—67; Cu: 40—77; Ni: 87—156; Pb: 48—94; Zn: 71—129; Fe: 26—34 g kg—1; Mn: 1.1—2.4). Decreasing Cd, Cu, Mn, and Pb concentrations with increasing soil depth pointed at atmospheric inputs. Aluminum and Ni concentrations increased with soil depth. Those of Fe, Cr, and Zn did not change with depth indicating that inputs at most equalled leaching losses. The Pb accumulation in the surface layer (i.e. the ratio between the Pb concentrations at 0—10 to those at 20—40 cm depth) was most pronounced at N-exposed sites; Pb obviously reached Mount Križna mainly by long-range transport from N where several industrial agglomerations are located. Substantial Cd, Cu, and Mn accumulations at the S- and SE-exposed sites indicated local sources such as mining near to the study area which probably are also the reason for slight Cr and Zn accumulations in the SE-exposed soils. Based on a principal component analysis of the total concentrations in the topsoils four metal groups may be distinguished: 1. Cr, Ni, Zn; 2. Mn, Cd; 3. Pb (positive loading), Cu (negative loading); 4. Al, Fe, indicating common sources and distribution patterns. The results demonstrate that the spatial distribution of soil heavy metal concentrations can be used as indication of the location of pollution sources.  相似文献   

14.
For analyzing the spatial distribution of the Cd, Co, Cu, Ni, Pb, Zn, and heavy metal (HM) sources on the Bafra deltaic plain (the central Black Sea district of Turkey), 108 soil samples were collected from the 0- to 20-cm layer in an area of about 100 thousand ha. The soil enrichment factor (the ratio between the metal concentration in the soil samples and its content in the earth’s crust (EF)) was calculated to reveal the origin of the heavy metal (HM) pollution (natural or anthropogenic). Kriging interpolation and maps of the soil’s enrichment factors were used for the characterization of the spatial HM distribution. The maximal EF was found for Cd (12.826), while smaller EF values characterized the Pb, Ni, Co, and Cu. In some districts of the studied region, the Cd, Cu, and Zn concentrations were somewhat greater, probably, due to the application of high rates of phosphorus fertilizers and intense soil cultivation. A content exceeding the critical value was recorded for Ni. Probably, this fact was related to the elevated content of this metal in the parent rocks. None of the investigated soils can be referred to the category of polluted ones.  相似文献   

15.
高精度X射线荧光光谱仪(HDXRF)是一种准确度较高的金属元素快速检测仪器。本研究将HDXRF法与电感耦合等离子体质谱(ICP-MS)法进行对比研究,探究HDXRF法在土壤重金属调查评估中的适用性。选取威宁县黑石头镇某地为研究区,基于地理探测器,以土壤理化性质(p H、有机质、CEC、黏粒、粉粒、砂粒)和地形因素(高程、坡度、坡向) 9个因子为自变量,重金属(Cd、Pb、Zn、Cr、Cu、Ni)含量为因变量,分析两种检测方法下耕地土壤重金属空间分布规律及其影响因素。结果表明:6种重金属的HDXRF法与ICP-MS法检测值均服从正态分布,两种方法检测得到的土壤重金属在耕层和剖面的分布规律基本一致,从数据统计上看,仅HDXRF法Cu的值比ICP-MS法高约16%,其他元素无显著差异。HDXRF法与ICP-MS法所测相同重金属间均存在极显著正相关关系(P<0.01),与各影响因子间相关性分析结果基本一致,Cd、Pb、Zn、Ni与土壤理化性质,Cr与土壤理化性质、高程和坡向,Cu与CEC和高程间均存在极显著相关关系(P<0.01)。地理探测器交互探测结果显示,影响因子间交互作用均显...  相似文献   

16.
红透山铜尾矿重金属分布及其对土壤重金属污染的影响   总被引:7,自引:1,他引:6  
通过对红透山铜尾矿重金属分布及尾矿区和农田区土壤重金属污染状况进行研究,结果显示:尾矿中四种重金属Cu、Zn、Pb、Cd均出现不同程度的淋滤-富集现象,对周围土壤存在较大的环境威胁。尾矿区土壤综合污染指数16.27,达重污染程度;周围农田土壤为轻度污染,综合污染指数1.29。四种重金属的污染状况分别为:Cd、Cu为重度污染,Zn为轻度污染,Pb为安全级别。  相似文献   

17.

Purpose  

The present work concerns the distribution of ten heavy metals (Sb, As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn) in the surrounding agricultural soils of the world largest antimony (Sb) mine in China. The objective is to explore the degree and spatial distribution of heavy metal pollution of the Sb mine-affected agricultural soils. The presented data were compared with metal concentrations in soils from mining and smelting sites in China and other countries.  相似文献   

18.
南宁市郊部分菜区土壤和蔬菜重金属污染评价   总被引:31,自引:0,他引:31  
对南宁市郊 1 2个主要菜区土壤和蔬菜中重金属 ( Cu、Zn、Cd、Pb)含量调查和分析测定 ,采用重金属污染单因子评价方法对土壤重金属污染状况进行评价 ,以国家规定的蔬菜卫生标准评价蔬菜重金属污染状况 ,结果表明 :南宁市郊部分蔬菜区土壤不同程度地受到了 Cu、 Zn、 Cd、 Pb的污染 ,依次是 :Cd>Pb>Zn>Cu;蔬菜中 Cd、 Pb积累较 Cu、 Zn高 ,供试点中大部分蔬菜 Cd、 Pb含量超出了国家规定的蔬菜卫生标准  相似文献   

19.
重金属污染土壤中菠菜对铅吸收和累积规律的研究   总被引:2,自引:0,他引:2  
通过盆栽试验对苗期和收获期菠菜地上部和地下部的重金属含量进行测定,并计算各元素的累积率和分配率,以了解土壤Pb污染和重金属复合污染条件下菠菜Pb的吸收和积累规律。结果表明,Pb、Cd、Cu、Zn复合污染条件下对Pb毒害起到抑制作用;在Pb、Cd、Cu、Zn复合污染条件下,Cd、Cu、Zn等金属离子的存在抑制了菠菜根系对Pb离子的吸收,而对菠菜植株内Pb离子的运转影响不大。在本试验条件下,Pb元素在地上部的分配率较低,为14.73%~28.72%。  相似文献   

20.
Analysis of vegetation and soils of the Rhondda Fawr, South Wales, shows that there is contamination by the heavy metals Pb, Cd, Cu and Ni throughout the valley, in particular within the urban development area. It is suggested that this contamination occurs mainly by aerial deposition, and that in the case of Pb, Cd and Ni the motor vehicle is the primary source. A correlation between the average heavy metal load of the soil of the urban strip, the urban strip width, and traffic frequency is established. Levels of heavy metals in soils and grasses within rural areas of the valley could be high enough to affect N mineralization in the soil, and could also have adverse effects upon grazing animals.  相似文献   

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