首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
矿粮复合区土壤-作物系统重金属污染风险性评价   总被引:4,自引:0,他引:4  
为分析矿区污染农田农作物生产的生态安全性,以焦作市中马村矿区的典型农田为例,对矿区农田土壤及植物中Zn、Cr、Cd、Cu和Pb等重金属的质量分数进行了测定,并对重金属污染风险进行了评价。结果表明,根据重金属的单项污染指数,在矿井水污灌农田(F1样地)土壤中Zn和Cd的质量分数达到中度污染水平,Cr的质量分数达到轻微污染水平,Cu和Pb元素质量分数未达到污染水平。在煤矸石污染农田(F2样地)土壤中Zn、Cr和Cd的质量分数达到轻度污染水平,Cu和Pb元素质量分数未达到污染水平。在矿区公路侧农田(F3样地)土壤中各元素质量分数均未达到污染水平。采用潜在生态风险指数法对土壤重金属污染的生态风险进行评价,F1和F2样地综合生态风险指数分别为239.60和178.42,达到中等水平,F3样地土壤达到轻微生态风险水平。采用单项污染指数和综合污染指数法对小麦(Triticumaestivum)籽粒中重金属风险进行评价,在F1和F2样地中,小麦籽粒中Cu质量分数均未达到污染水平,Pb、Cd和Cr质量分数均达到重度污染水平。Zn质量分数在Fl样地中达到轻度污染水平,在F2样地中达到中度污染水平。在F3样地中,小麦籽粒中Cd和Cu质量分数未达到污染水平,Zn质量分数达到轻度污染水平,Pb、Cr质量分数达到重度污染水平。从综合污染指数评价来看,F1、F2和F33个样地小麦籽粒中重金属污染综合指数均达到重度污染水平。评价结果对科学治理矿区污染土壤,确保矿区农田生态安全、粮食生产安全具有重要意义。  相似文献   

2.
原海燕  黄苏珍  郭智 《生态环境》2010,19(8):1918-1922
通过野外调查和实地修复铅锌矿污染土壤试验,研究了铅锌矿区排污渠污水及底泥中Pb、Zn、Cu、Cd含量和分布特征以及4种鸢尾属植物马蔺(Iris lactea var.chinensis)、黄菖蒲(Iris pseudacorus L.)、溪荪(Iris sanguinea Donn ex Horn.)、花菖蒲(Iris ensata Thunb.)对Pb、Zn、Cu、Cd的积累能力和土壤修复效率差异。结果表明,离污染源越近,重金属污染越严重。Pb、Zn、Cu、Cd4种重金属均大部分沉积在排污水渠的底泥中,污水中Pb严重污染,超标达120倍,底泥中Pb、Zn、Cu、Cd质量分数分别超标1.5倍、1.7倍、1.6倍和1.7倍。排污渠岸土壤Pb、Zn、Cu、Cd质量分数也明显超过了国家规定的土壤环境质量Ⅱ级标准1~5倍。种植4种鸢尾属植物后,土壤中Pb、Zn、Cu、Cd质量分数有所降低。其中,种植马蔺1个月后土壤Pb、Cu、Cd修复效率分别为8.13%、2.45%和22.3%。黄菖蒲和花菖蒲对Zn的修复效率相对较高。4种鸢尾属植物中马蔺对Pb、Cd的吸收能力最强,马蔺地上部(叶、茎)Pb质量分数达983mg·kg-1,且转运系数大于1,是一种潜在的Pb积累植物,黄菖蒲、溪荪和花菖蒲对Zn的吸收能力较强,且吸收的重金属主要积累在根系。  相似文献   

3.
张军  陈功锡  杨兵  廖斌 《生态环境》2011,(6):1133-1137
宝山堇菜Viola baoshanensis Shu,Liu et Lan是一种Cd超富集植物,但它对不同重金属的吸收和转运能力有待进一步研究。从湖南桂阳宝山多金属矿区中筛选4个宝山堇菜优势分布的小生境,分析这些生境中宝山堇菜及其根区土壤的重金属质量分数。化学分析结果显示,宝山堇菜优势分布土壤中Cd、Pb、Zn、Cu、Mn和Fe的平均质量分数(mg/kg)分别为471、15 044、8 273、1 776、4 702和69 054。宝山堇菜地上部Cd、Pb、Zn、Cu、Mn和Fe的平均质量分数(mg/kg)分别为387、1 077、1 037、99、379和1 812,其中Cd、Pb超过超富集植物标准,Zn、Cu的平均质量分数大约是Zn、Cu超富集植物标准的10%,Mn的平均质量分数低于Mn超富集植物标准的5%,Fe的平均质量分数高于1 000 mg/kg。上述结果表明,宝山堇菜可以超富集Cd和Pb,富集Zn、Cu和Fe以及低积累Mn。此外,宝山堇菜对不同重金属差别化吸收模式可能也代表了超富集植物适应重金属复合污染土壤的一种策略。  相似文献   

4.
宝山堇菜Viola baoshanensis Shu,Liu et Lan是一种Cd超富集植物,但它对不同重金属的吸收和转运能力有待进一步研究。从湖南桂阳宝山多金属矿区中筛选4个宝山堇菜优势分布的小生境,分析这些生境中宝山堇菜及其根区土壤的重金属质量分数。化学分析结果显示,宝山堇菜优势分布土壤中Cd、Pb、Zn、Cu、Mn和Fe的平均质量分数(mg/kg)分别为471、15 044、8 273、1 776、4 702和69 054。宝山堇菜地上部Cd、Pb、Zn、Cu、Mn和Fe的平均质量分数(mg/kg)分别为387、1 077、1 037、99、379和1 812,其中Cd、Pb超过超富集植物标准,Zn、Cu的平均质量分数大约是Zn、Cu超富集植物标准的10%,Mn的平均质量分数低于Mn超富集植物标准的5%,Fe的平均质量分数高于1 000 mg/kg。上述结果表明,宝山堇菜可以超富集Cd和Pb,富集Zn、Cu和Fe以及低积累Mn。此外,宝山堇菜对不同重金属差别化吸收模式可能也代表了超富集植物适应重金属复合污染土壤的一种策略。  相似文献   

5.
在白银市城郊东大沟沿程采集了8个沉积物样品,采用Tessier五步连续提取法和静态释放试验研究了沉积物中重金属的污染特征及在不同离子强度条件下沉积物中重金属的释放规律.结果表明:(1)东大沟沉积物中Cd、Cu、Pb、Zn的含量均超过了甘肃省土壤元素背景值,其平均值分别为背景值的128.83、12.71、26.90、17.99倍.(2)沉积物中Cd和Cu主要以残渣态和有机结合态存在,Zn主要以有机结合态和铁锰氧化物结合化态存在,Pb主要以铁锰氧化物结合态存在;沉积物中重金属的活性顺序为ZnPbCdCu.(3)随着离子强度的增大,沉积物中Cu、Pb、Zn的释放量随之增加,沉积物中Cd的释放量则是先增加后减少.  相似文献   

6.
青岛城市土壤重金属的形态分布及影响因素分析   总被引:8,自引:0,他引:8  
钱翌  张玮  冉德超 《环境化学》2011,30(3):652-657
选取青岛市不同功能区63个代表性的表层土壤样品,分析了其重金属元素的含量和存在形态.结果表明,青岛城市土壤中Cu、Zn、Pb、Cd均受到不同程度的污染,其中Cd属于重度污染,土壤重金属累积污染程度为Cd>Zn>Cu>Pb.Cu和Zn主要以残渣态为主,Pb主要以残渣态和铁锰氧化态为主,Cd主要以残渣态和有机结合态为主;土...  相似文献   

7.
在铅锌冶炼过程中产生了大量含重金属的废渣,这些废渣未经有效处置堆放于空旷地,由于风化、淋洗等作用导致废渣中重金属进入废渣堆场及周边土壤中。采用野外取样调查、室内化学分析及污染评价等方法,研究了湖南某铅锌冶炼厂冶炼废渣堆场及周边土壤中重金属的含量和分布规律。研究结果表明:废渣堆场表层土壤中各重金属的质量分数分别为Pb1 889.60 mg·kg-1、Zn 5 682.00 mg·kg-1、Cd 48.40 mg·kg-1和Cu 1 848.60 mg·kg-1,此值已超出国家规定的二级标准值(GB 15618─1995),其中Pb超出5.40倍,Zn超出18.94倍,Cd超出80.67倍,Cu超出18.49倍。距渣场10 m远处表层土壤中Pb、Zn、Cd和Cu的质量分数分别为641.01、1 509.61、38.45和1 240.10 mg·kg-1,10 m远处表层土壤中Pb、Zn、Cd和Cu相对国家二级标准值的超标倍数分别为2.14、6.04、128.17和12.40倍。1 000 m远处表层土壤中Pb、Zn、Cd和Cu的质量分数分别为309.80、685.71、8.81和875.13 mg·kg-1,1 000 m远处表层土壤中Pb、Zn、Cd和Cu各超标1.03倍、2.74倍、29.33倍和8.75倍。由此可见,废渣堆场周边土壤同样遭受重金属Pb、Zn、Cd和Cu不同程度的污染。纵向上,废渣堆场土壤重金属Pb、Zn、Cd和Cu在表层(0~20 cm)土壤中的质量分数均大于其在表层以下各土层中的质量分数,其中在40~60 cm土层中的质量分数又高于20~40,60~80和80~100 cm等土层,但其分布总体上呈现出随土层深度增加而减少的规律;横向上,废渣堆场各土壤剖层重金属Pb、Zn、Cd和Cu的质量分数均高于渣场外10和1 000 m远处各土层的质量分数,即土壤中重金属含量随距污染源距离的增加而逐渐减少。因此,冶炼废渣的大量堆置已使周围环境遭受了重金属的严重污染,相关部门有必要加强对冶炼废渣的处置和管理。  相似文献   

8.
利用地统计学方法,研究了广西岩溶地区某铅锌矿区农田土壤中Cd、Zn、Pb、Cu四种重金属有效态含量的空间分布特征及其影响因子.结果表明:研究区域不同程度地受到Cd、Zn、Pb、Cu的污染,且水田污染较旱地严重;与广西土壤背景值相比,污染程度最严重的是Cd,在水田和旱地中超标率均为100%,平均超标倍数分别为312.94和33.67;其次是Zn,在水田和早地中超标率分别为100%和34%,平均超标倍数分别为38.34和2.11;污染最轻的为Cu,超标率仅为7%.空间分析表明,有效态Cd、Zn、Pb、Cu的块金系数分别为2.7%、0.2%、6.5%、0.13%,体现了强烈的空间自相关性,且四种重金属空间分布特征相似,在离原铅锌选矿厂较近的西北偏西面有效态Cd、Zn、Pb、Cu含量最高,沿着西北偏西至东南偏东的灌溉渠流向,有效态Cd、Zn、Pb、Cu的含量呈递减趋势,东部旱地有效态Cd、Zn、Pb、Cu含量相对较低.土壤有效态Cd、Zn、Pb、Cu在污染区的空间分布与土壤基本理化性质关系密切,有效态Cd、Zn、Pb、Cu与pH、阳离子交换量、粘粒都呈极显著负相关,与有机质含量则呈极显著正相关.  相似文献   

9.
兰砥中  雷鸣  周爽  彭亮  廖柏寒  沈跃 《环境化学》2014,(8):1307-1313
为了探究湘南某铅锌矿区尾砂坝垮坝之后,该区域周围的农业土壤中重金属污染情况,在该矿区周围采集农业土壤,分析土壤中Pb、Zn、Cu、Cd和As的含量,分别运用单因子指数和潜在生态风险指数评价土壤重金属的污染状况和潜在生态风险.结果表明,土壤中Pb、Zn、Cu、Cd、As的平均含量分别为566.82、285.90、69.00、10.29、670.12 mg·kg-1,该矿区周围的农业土壤仍旧受到不同程度重金属污染,其中Cd的污染指数最髙;所有农业土壤中Pb、Zn、Cu、Cd和As的潜在生态危害性顺序是Cd>As>Pb>Cu>Zn,其中Cd和As是主要的生态风险的贡献因子.该区域的农业土壤受到重金属污染程度并没有随着时间而有所减轻.  相似文献   

10.
矿区污染土壤Pb、Cd、Cu和Zn的形态分布及其生物活性的研究   总被引:11,自引:3,他引:11  
调查湘南某铅锌矿区周围的菜园土和水稻土Pb、Cd、Cu和Zn的形态分布及其生物活性和迁移性。结果表明:两种土壤中Pb、Cd、Cu和Zn的总量分别超过国家土壤环境质量相应的标准。运用Tessier连续提取法研究发现,土壤中Pb、Cd、Cu和Zn的各形态含量之和与其总量非常的接近,其中菜园土Pb的提取率为96.3%,Cd的为94.1%,Cu的为93.4%和Zn的为91.7%;水稻土Pb的为97.6%,Cd的为92.0%,Cu的为92.1%和Zn的为91.7%,表明该形态分析方法的结果是合理的。土壤中Pb、Cd、Cu和Zn各形态的分布存在很大的差别,残渣态是主要形态,其中Pb的含量占60.7%~58.2%,Cd的是50.4%~59.2%,Cu的是37.3%~53.4%,Zn的是54.9%~46.9%,而交换态所占的比例最小。菜园土重金属的生物活性系数的大小是:Cd>Cu>Pb>Zn,迁移能力的顺序是Cd>Cu>Zn>Pb;水稻土重金属的活性大小和迁移能力的顺序都是:Cd>Pb>Zn>Cu。菜园土重金属的生物活性和迁移性较水稻土的大,其中Cd的生物活性和迁移性的最大。研究结果将为评估矿区污染土壤中重金属的危害提供科学依据。  相似文献   

11.
污染黑土中重金属的形态分布与生物活性研究   总被引:31,自引:5,他引:31  
郭观林  周启星 《环境化学》2005,24(4):383-388
通过对污染和清洁黑土的耕层、非耕层分层采样分析,比较了Cd,Pb,Cu和Zn等在同一土壤耕层和非耕层以及不同采样点土壤中的形态分布和生物活性.结果表明,无污染黑土中这些重金属的形态分布一般为:残渣态>有机结合态>铁锰结合态>碳酸盐结合态>可交换态,外源污染则使可交换态重金属的含量增加.以生物有效性系数和迁移系数进行重金属生物活性评价,其在黑土中生物活性大小的顺序为:Cd>Cu>Zn>Pb.污染愈严重的土壤,重金属的生物活性和自身的淋溶能力相对较强,在非耕层中也表现出较高的生物活性.综合重金属在土壤中的含量和生物活性,发现2个污染点的黑土中Cd和Pb对当地农业生产和地下水安全已构成潜在的威胁.  相似文献   

12.
土壤重金属化学形态的生物可利用性评价   总被引:59,自引:0,他引:59  
雷鸣  廖柏寒  秦普丰 《生态环境》2007,16(5):1551-1556
重金属化学形态是近年来土壤化学、植物营养和环境科学研究领域的一个热点和难点,利用重金属的化学形态分布和含量变化来评价重金属的生物可利用性,有利于全面研究重金属的危害性和治理重金属污染土壤。结果表明,水溶态和交换态的重金属易被生物吸收利用,而残留态重金属一般不被生物利用,其它形态如碳酸盐结合态、铁锰氧化物结合态和有机物结合态的生物可利用性主要取决于外界环境的变化。  相似文献   

13.
《Chemistry and Ecology》2008,24(2):147-156
The main objective of this study was to investigate the efficiency of different substrates to reduce the extraction of heavy metals concentration in a heavily contaminated soil. Two contaminated soils by Cu and Zn were used to evaluate the effectiveness of eight substrates (calcium carbonate, bentonite, kaolinite, charcoal, manganese oxide, iron oxide, zeolite, phosphate) to reduce metal availability and to study the change of metals speciation in different forms using sequential extraction technique (single step). Sequential extraction technique (single step, 0.11 M acetic acid, HONH3Cl, H2O2+NH4OAc, Aqua regia) was applied on contaminated soils after and before treatment to evaluate metals speciation. Results indicate that the most effective treatments in decreasing available metal concentrations were calcium carbonate, zeolite and manganese or iron oxide. Metal sequential fractionations indicate that the exchangeable fraction of Cu and Zn in contaminated soils can be transformed into unavailable forms after chemical remediation.  相似文献   

14.
Acid rain is a serious environmental problem worldwide. In the present study, we investigated the effect of acid rain (1:1 equivalent basis H2SO4:HNO3) at pH values of 2.0, 4.0 and 7.0 on the fractionation of heavy metals (Cd, Cu, Fe, Mn, Ni, Pb and Zn) and major elements (K, Na, Ca, and Mg) in contaminated calcareous soils over a 2084 h period. Heavy metals and major elements in soil samples were fractionated before and after 2084 h kinetic release using a sequential extraction procedure. Before kinetic studies the predominant fractions of K, Na, Ca, Mg, Cd and Ni were mainly associated with carbonate fraction (CARB), whereas Fe, Mn and Zn were associated with the Fe–Mn oxide fraction (Fe–Mn oxide). The highest percentage of Pb and Cu were found in the exchangeable (EXC) and organic matter (OM) fractions, respectively. After kinetic study using different simulated acid rain solutions, the major fractions of heavy metals (expect of Cu) and Na was the same as before release. Upon the application of different acid rain solutions, K and Mg were found dominantly in Fe–Mn oxide fraction, whereas Ca was in the EXC fraction. The results provide valuable information regarding metal mobility and indicated that speciation of metals (Cu and Zn) and major elements in contaminated calcareous soils can be affected by acid rain.  相似文献   

15.
韶关地区大宝山铁多金属矿产资源的开采给环境带来了严重的危害。采选冶产生的废液及固体废弃物堆积的淋滤酸水,携带浸滤出的大量重金属离子排入下游河道,严重影响矿区及酸水流域的生态环境。通过对该铅锌矿区土壤重金属分布、土壤微生物数量与植物重金属积累特征进行采样分析研究,结果表明:铅锌矿区土壤各重金属元素质量分数均高于对照土壤,矿区土壤均受到不同程度的污染;五节芒(Miscanthusfloridulus)植物中的元素质量分数表现为Zn〉Pb〉Cu〉Cd,Zn与土壤元素的相关性最为显著,其次为Pb;与对照土壤相比,矿区土壤微生物总数下降了68.43%-80.32%,各主要生理类群数量均呈下降趋势。矿区土壤生态系统处于不利于有益微生物的繁殖和活动的境地,从而大大削弱了土壤中C、N营养元素循环速率和能量流动。  相似文献   

16.
Contamination by heavy metals is the result of different industrial activities. The presence of heavy metals in soil and water causes serious problems, as these materials are not biodegradable and do contaminate both biological systems and the subsoil. Biological surface-active compounds otherwise known as biosurfactants in general and rhamnolipids biosurfactants in particular have been successfully employed in the remediation of environments contaminated with heavy metal ions. The aim of the present review is to highlight potential applications of these tensioactive compounds for use in environmental heavy metals removal and bioremediation and processes involved.  相似文献   

17.
长期受到重金属铅(Pb)和镉(Cd)污染的土壤生态危害指数较高,土壤微生物群落结构容易受到重金属的影响,重金属对土壤微生物的毒性与重金属的生物利用度直接相关。以白银市重金属污染土壤为样本,分析了土壤的理化性质、重金属Pb和Cd的污染状况及土壤微生物群落结构,探究它们之间的关联性。样本采自距离污染中心由近及远的4个位置(分别命名为S1、S2、S3和S4)。采用Hakanson指数法来评估该地重金属生态风险;选用改进的BCR顺序提取法分析Pb与Cd的组分分布情况;利用SPSS和Canoco 4.5对土壤性质、重金属和细菌群落进行相关性分析和冗余分析,探究微生物群落结构与土壤性质和重金属污染之间的相关性。结果表明:白银市该处重金属污染场地3 km以内的土壤均受到严重的Pb、Cd污染。Pb主要以弱酸可提取态和可还原态的形式存在于土壤中,Cd则以弱酸可提取态为主;土壤重金属的危害生态指数均已经达到极高污染风险程度,且危害程度S1>S3>S2>S4;微生物丰度和多样性可能受到土壤性质及重金属的共同影响,与Pb、Cd的污染程度大致呈负相关(S2相似文献   

18.
Tailings, agricultural soils, vegetables and groundwater samples were collected from abandoned metal mines (Duckum, Dongil, Dongjung, Myoungbong and Songchun mines) in Korea. Total concentrations of arsenic (As) and heavy metals (Cd, Cu, Pb and Zn) were analyzed to investigate the contamination level. Several digestion methods (Toxicity characteristics leaching procedure (TCLP), synthetic precipitation leaching procedure (SPLP), 0.1 N/1 N HCl) and sequential extraction analysis for mine tailings were conducted to examine the potential leachability of As and heavy metals from the tailings. The order of urgent remediation for the studied mines based on the risk assessment and remedial goals was suggested. The Songchun mine tailings were most severely contaminated by As and heavy metals. Total concentrations of As and Pb in the tailings were 38,600–58,700 mg/kg (av. 47,400 mg/kg) and 11,800–16,800 mg/kg (av. 14,600 mg/kg), respectively. Agricultural soils having high As concentrations were found at the all mines. Average concentrations of Cd in the vegetables exceeded the normal value at all mines areas, while As only at the Dongjung, Myoungbong, and Songchun mine area. One groundwater sample each from the Dongil and Myoungbong mines, and 4 groundwater samples from the Songchun mine had values above 10 μg/L of As concentration. The TCLP method revealed that only Pb in the Songchun tailings, 6.49 mg/L, exceeded the regulatory level (5 mg/L). Employing the 1-N HCl digestion method, the concentration of As in the Songchun mine tailings, 4,250 mg/kg, was up to 3,000 times higher than its Korean countermeasure standard. Results from the sequential extraction of As in the tailings showed that the easily releasable fraction in the Myoungbong and Songchun mine tailings was more than 30% and the residual fraction was less than 40%. Based on results showing the exposure health risk employing the hazard quotient and cancer risk of As, Cd and Zn, the Dongil mine needs the most urgent remedial action. The concentration reduction factor (CRF) of As in both soil and groundwater follows the order: Songchun>Dongjung>Dongil>Myoungbong>Duckum mine.  相似文献   

19.
The objective of this study is to compare Anyang River bed sediments with water chemical composition and to assess the anthropogenic chemical inputs into the river system. Eight sampling locations were chosen along the river channel. Bed and suspended river sediments and water samples were collected, and analyzed for their chemical and physical composition. Data revealed that trace element concentrations in the river water were generally below world average, except for As, Mn, Ni and Cr. Among the three phases: water, bed and suspended sediment, more than 99% of the trace elements was associated with the bed sediment. Concentrations of trace elements in the sediment were a function a particle size distribution and organic content. The calculated degrees of enrichment based on the least influenced sample (ASD 1) indicated the river sediments were enriched with respect to background. The enrichment factors for Pb, Zn and As were relatively lower than for Cr, Co, Ni and Zn. The difference in the enrichment seems to reflect the human activities influence in the basin, and specially for Cd. Speciation of the elements in the five different chemical forms in the sediment by sequential extraction indicated that the reducible fraction was predominant for Fe, Zinc and Cu showed an irregular variation among the different fractions; whereas, Cd and Pb were more regular. Zinc and Cu highly existed mostly in exchangeable forms. Acid soluble and reducible forms were also important for most metals. The speciation implies that the metals associated with the sediment are subject to release into water bodies as goechemical variables (pH and Eh) change. Currently, the introduced metals are deposited near the source area and are mostly associated with the sediment, implying that the river bed sediment acts mainly as a sink, rather than a pool. The accumulated and enriched toxic trace elements can pose a potential pollution of river water.  相似文献   

20.
A five-step sequential extraction technique was used to determine the chemical association of heavy metals (Pb, Zn, Cu and Cd), with major sedimentary phases (exchangeable, surface oxide and carbonate, Fe and Mn oxides, organic and residual metal ions), in samples from floodplain and recent flood sediments of the River Aire, West Yorkshire. Analysis indicates that metals Pb and Zn are primarily associated with the Fe and Mn oxides, Cu with the organic fraction and Cd with exchangeable and surface oxide and carbonate metal ions. Knowledge of the chemical speciation of heavy metals in river sediment, despite the procedure's inherent limitations, facilitates an understanding of their bioavailability, storage and remobilisation in floodplain and river channel environments.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号