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1.
以长沙某河库兼用型饮用水水源地一、二级保护区土壤为研究对象,于2018年8月采用网格布点法在一级和二级保护区分别布设3个和7个采样点,在水源地历史采样区布设5个采样点,探究土壤中Cd、Pb、Cr、Cu、Zn、Ni、Hg、As的含量分布及污染水平。结果表明:土壤中As、Cd、Cr、Cu、Hg、Ni、Pb、Zn的含量均值分别为46.56、4.90、81.87、46.64、0.19、30.11、75.11、237.93 mg/kg。重金属元素含量均值超过农用地污染风险筛选值的样品占比排序为Cd (86.7%)>Zn (60%)>As (53.3%)>Cu (6.7%)=Pb (6.7%)。土壤中As、Cd、Cr、Cu、Hg、Ni、Pb、Zn的单因子污染指数分别为1.55、16.34、0.41、0.47、0.08、0.30、0.63、0.95,主要为Cd、As污染。研究区土壤重金属综合污染指数为11.71,属重污染等级。水源地一级保护区、二级保护区、历史采样区2018年、历史采样区2014年土壤重金属综合污染指数分别为20.41、14.94、1.98、1.17。后期应加强对该饮用水水源地土壤中Cd、Pb、Cu、Zn、As的污染控制和治理。  相似文献   

2.
天津近郊农田土壤重金属污染特征及潜在生态风险评价   总被引:9,自引:5,他引:4  
以天津近郊西青区主要农产品生产基地农田表层土壤(0~20cm)作为调查对象,分析了土壤中重金属As、Hg、Zn、Pb、Cu、Cr和Cd的含量,通过数据统计分析,各项重金属平均含量均低于《土壤环境质量标准》(GB 15618—1995)二级标准,但高于天津土壤背景值和全国土壤背景值,Cd、Cu、Hg在个别点位出现超标现象。多数点位土壤内梅罗综合污染指数处于清洁水平。潜在生态风险评价表明,各点位土壤重金属潜在生态风险指数(RI)为12.96~104.49,均处于轻微生态风险水平。  相似文献   

3.
对淮安市某垃圾填埋场土壤中13个采样点中典型重金属 Cr、Pb、As、Hg、Cd、Cu、Zn 的含量进行了调查,采用单因子污染指数、综合污染指数及 Hakanson潜在生态风险指数法评价了土壤中典型重金属对其所在环境的污染程度,对周围环境造成的潜在生态风险影响。结果表明,研究区域内重金属含量均未超过《土壤环境质量标准》(GB 15618-1995)二级标准。主要的潜在生态风险因子为 As,潜在生态风险因子大小顺序为 As>Hg>Cd>Cu>Cr>Pb>Zn。  相似文献   

4.
洞庭湖表层沉积物中重金属污染特征、来源与生态风险   总被引:6,自引:1,他引:5  
选择洞庭湖9个有代表性的样点,研究了洞庭湖表层沉积物中重金属的空间分布特征、主要来源与生态风险。结果表明,洞庭湖Cd、Hg、As、Cu、Pb、Cr的含量分别为0.60~20.70、0.090~0.640、10.4~83.7、17.9~70.9、16.9~95.8、59.0~199.0 mg/kg,Cd、As出现超过土壤环境质量三级标准的现象,是主要重金属污染物;Cd、Hg的空间分布相似,表现为南洞庭湖区西洞庭湖区东洞庭湖区;As、Cu、Pb、Cr的空间分布相似,表现为南洞庭湖区东洞庭湖区西洞庭湖区。相关分析结果显示:As、Cd、Hg、Cu、Pb之间呈显著正相关,Cr与其它重金属之间没有显著的相关性。主成分分析结果表明,第一主成分的Hg、As、Cd主要受工矿业采冶支配,第二主成分的Cr、Pb、Cu主要与生活污水排放和农业生产有关。沉积物质量基准法初步评价结果表明,洞庭湖Cd、Hg、As、Cu、Pb、Cr等重金属均具有引起较低生态风险的可能性,部分点位Cd、As、Cr具有引起较高生态风险的可能性。受Cd、As含量较高的影响,南洞庭湖区具有较高的生态风险。  相似文献   

5.
通过在丰水期对贵州省某流域城市河段悬浮物和沉积物中的重金属含量进行测定,运用单因子指数法、生态风险评价法、因子分析法,初步探讨了该河段Cu、Zn、Pb、Hg、Cd、Cr、Ni及As等8种重金属元素的含量分布、污染特征、潜在生态风险及主要来源。检测结果显示,沉积物和悬浮物中Hg、Cd、Zn、Pb、As的平均含量较高,是贵州省土壤背景值的1.02~16.97倍。单因子指数评价结果表明:在沉积物中,Zn、Pb、As为轻度污染,Hg和Cd为重度污染;在悬浮物中,Cu、Pb、As为轻度污染,Zn为中度污染,Hg和Cd为重度污染。潜在生态风险指数评价结果显示,Hg和Cd的生态风险最大,为主要污染元素。研究区沉积物样品综合生态风险指数(RI)介于183.27~1 393.96,平均值为912.06,总体处于严重生态风险等级;悬浮物样品RI值介于341.53~612.38,平均值为436.85,总体处于重度生态风险等级。其中,沉积物样品重金属平均生态风险等级高于悬浮物样品,支流样品重金属生态风险等级总体上低于干流下游样品。根据因子分析法分析结果,初步推测沉积物及悬浮物Hg、Cd、Cr、Ni含量主要受工...  相似文献   

6.
对南通市51个沉积物样品中重金属Cu、Pb、Cr、Hg、As、Cd的质量浓度进行了测试,并用地积累指数法评价了河流沉积物的重金属污染。结果表明:南通市沉积物重金属基本上未受污染,只有元素As受到轻度污染。  相似文献   

7.
为探索贵州煤矿区表层水-沉积物中重金属的分布特征及来源,科学制定环境保护与污染治理措施,以新寨河为研究对象,在11个样点共采集66个表层水体和沉积物样品,通过对Cd、Pb、Cr、Zn、Cu、As、Hg、Fe、Mn等9种重金属元素进行分析,揭示其在新寨河的空间分布特征。同时,利用多指数法开展了有毒重金属元素污染状况评价,通过相关性分析和主成分分析解析了重金属的来源。结果表明,新寨河流域表层水体中,Fe、Mn点位超标率达100%。表层水中重金属元素的平均含量排序为Fe>Mn>Zn>Cu>Cr>As>Cd>Pb>Hg,而沉积物中重金属元素的平均含量排序则是Fe>Mn>Zn>Cr>Cu>As>Pb>Cd>Hg,表明新寨河表层水体和沉积物中重金属元素的空间分布存在一定差异。各重金属元素的内梅罗综合污染指数介于0.59~1.13之间,表明新寨河表层水体中重金属的污染程度达到轻微污染水平。单种重金属元素的潜在生态危害系数计算结果显示,90.91%和9.09%的沉积物样点分别被归类为轻微风险和中等风险。所有样点沉积物的潜在生态危害指数介于14.57~120.55之间(均值为72.08),表明新寨河沉积物的潜在生态风险较低。Cu、As在多个样点存在污染现象,需予以重点监控管理。新寨河流域重金属的来源可分为三大类:Cd、Pb、Cr、Zn、Cu为第一类,对应地表径流源;As、Fe、Mn为第二类,对应煤矿开采源;Hg为第三类,对应复合源。  相似文献   

8.
于2015年5—8月采集内蒙古自治区东部、中部和西部地区32个畜禽养殖场周边共160个土壤样品,分析8种重金属含量。通过单项污染指数法和内梅罗综合污染指数法评价畜禽养殖场周边土壤重金属的污染程度,主成分分析重金属污染的成因和来源。结果表明,除Hg和As外,Cd、Pb、Cr、Cu、Zn和Ni 6种重金属的平均值均高于内蒙古自治区土壤背景值,其中Cd是背景值的2. 14倍。单项污染指数评价表明,重金属Cd在东部畜禽养殖场周边土壤中呈中度污染,在中部和西部地区畜禽养殖场周边土壤中呈轻度污染。不同重金属元素平均污染程度为:Cd Pb Cr(Ni) Zn Cu As Hg。内梅罗综合污染指数评价表明,东部地区畜禽养殖场周边土壤污染最严重,为中度污染,中部和西部地区畜禽养殖场周边土壤均为轻度污染。不同地区畜禽养殖场周边土壤重金属内梅罗综合污染指数大小顺序为:东部地区(2. 27)西部地区(1. 52)中部地区(1. 35)。主成分分析结果显示,内蒙古不同地区畜禽养殖场周边土壤不同重金属的来源存在差异,其中Pb、Cr、Cu、Zn和Ni主要来源于畜禽粪便和冲洗禽舍等污水的不当排放; Hg主要来源于自然源。  相似文献   

9.
镇江内江底泥重金属分布特征及潜在生态危害评价   总被引:7,自引:1,他引:6  
对镇江内江的底泥进行采集,测定底泥中的Cu、As、Hg、Cr、Pb、Cd、Zn、总磷、总氮、有机质的含量,采用潜在生态风险评价和相关性分析的方法,研究了底泥中重金属的污染水平、生态危害、分布特征和溯源。结果表明,(1)内江底泥中的重金属污染主要为Hg、Cd、As。各重金属单项潜在生态危害指数大小关系为Hg>Cd>As>Pb>Cu>Cr>Zn。(2)内江的整体生态环境受重金属的危害程度处在中等水平,重金属的生态威胁主要来自Hg,建议在达到强生态威胁程度的3#、8#、20#、21#采样点附近清理淤泥。(3)由重金属分布特征可知,湿地生态系统对重金属具有较好的吸附去除作用;在内江流速慢、死水多的地方易造成重金属富集;入江河口重金属富集也较明显;污染企业与重金属含量有直接关系。(4)由相关性探源可知,Cu、Zn、Cr主要来自于自然界,Hg、Cd、Pb主要来自于企业污水排放,As则来自于自然界和人为排放。  相似文献   

10.
某铀尾矿库周围农田土壤重金属污染潜在生态风险评价   总被引:6,自引:1,他引:5  
为能够定量评价铀尾矿库周围农田土壤重金属污染程度及其潜在生态危害性,采用Hakanson潜在生态风险指数法对土壤中重金属进行综合污染评价。结果表明,铀尾矿库周围部分农田土壤中重金属Cd、Ni、As、Cu、Hg、Zn含量存在积累和超标情况,尤以Cd的污染最严重,Ni、As次之;Pb、Cr含量能够满足标准限值要求。潜在生态风险评价结果显示,铀尾矿库周围农田土壤重金属潜在生态风险较高,主要潜在生态风险因子为Cd,其次是Hg、As,Cr、Pb、Ni、Cu、Zn并不构成潜在生态风险。铀尾矿库周围农田土壤中较高水平的Cd在构成环境污染的同时,也构成了较严重的生态危害,应加强对重金属Cd、Hg的生态风险防治。  相似文献   

11.
This study was conducted to determine status of heavy metals in agricultural soils under different patterns of land use. A total of 38, 40 and 45 soil samples for bare vegetable field, greenhouse vegetable field, and grain crop field were respectively taken from surface layer (0–20 cm) from selected experimental areas away from suburbs of ten counties (or districts or cities) in four provinces or municipalities of Huabei plain in north China. Information of crop production history, including varieties, rotation systems and fertilizer use, at the corresponding sampling sites was surveyed. Soil total Cu, Zn, Cd, Pb, Cr, As and Hg were measured. The results showed that the contents of total Cu, Zn, Cd, Pb, Cr, As, and Hg in the soil samples, especially soil total Cu and Zn contents, were higher in the bare vegetable field and the greenhouse vegetable field than that in the grain crop field. Long-term use of excessive chemical fertilizers and organic manures in the bare vegetable field and the greenhouse vegetable field contributed to the accumulation of Cu, Zn, and other heavy metals in the soils. The contents of total Cu, Zn, and other heavy metals in soils increased with increasing vegetable production history of the research areas. In comparison with the grain crop field, the comprehensive pollution indices of the seven soil heavy metals and the single-factor pollution indices of soil Zn, Cu, Cd, Cr, and Hg based on the second criterion of Environmental Quality Standard for Soils were significantly higher in the bare vegetable field and the greenhouse vegetable field. Soils from the greenhouse vegetable field were slightly contaminated according to the comprehensive pollution index, and soils from the bare vegetable field and the grain crop field were at the warning heavy metal pollution level. The soils were contaminated with Cd according to the single-factor pollution index. The Cd pollution was relatively more serious in the bare vegetable field and the greenhouse vegetable field than that in the grain crop field. The soils selected with different land use patterns were not contaminated with Zn, Cu, Pb, Cr, As and Hg.  相似文献   

12.
苏晓燕  董铮 《干旱环境监测》2013,(4):145-149,168
以2005年以后太湖无锡区域底质为研究对象,分析了太湖底泥中重金属的含量分布及富集状况,采用地积累指数法和潜在生态危害指数法对重金属的生态危害进行评价。结果表明:太湖无锡区域底质受重金属轻度污染,含量高于全国水系沉积物平均值;地积累指数法显示太湖无锡区域底质中重金属污染排序为Cu=As〉Pb〉Zn〉Cr〉Cd〉Hg;金属对太湖无锡区域底质构成的潜在生态危害由强到弱为Hg〉Cu〉As〉Cd〉Pb〉Cr〉Zn;从区域上看,2种评价方法均表明底质中重金属危害程度为宜兴沿岸区〉梅梁湖〉五里湖〉贡湖无锡水域。  相似文献   

13.
根据1990—2006年监测资料,对海河干流(市区段)沉积物中重金属的现状和变化趋势进行了分析,采用地积累指数和Hakanson危害指数对海河干流(市区段)沉积物重金属富集现状和对水生生物危害进行评估。结果显示:海河干流(市区段)表层沉积物除Zn外,均呈现污染下降趋势。海河干流(市区段)沉积物中重金属对生物潜在危害顺序为Cd〉Hg〉As〉Cu〉Pb〉Cr〉Zn,各项指标对生物潜在危害性上游大于下游。  相似文献   

14.
The aim of this paper is to evaluate total and bioavailable concentration of heavy metals in agricultural soils in order to estimate their distribution, to identify the possible correlations among toxic elements and the pollution sources, to distinguish the samples in relation to sampling site or to sampling depth, and to evaluate the available fraction providing information about the risky for plants. In particular, we reinvestigated total concentrations of As, Be, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, V, and Zn and available concentrations of As, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, and Zn in soil from Apulia (Southern Italy). Analytical results showed that total concentrations, for all soils, are in the range permitted by regulations in force in Italy, but some soils evidence slight enrichment of Cd, Cr, Cu, Pb, and Zn. All the heavy metals in the available fraction were below the detection limits of the analytical techniques used except Cu, Ni, Pb, and Zn.  相似文献   

15.
An intensive investigation was conducted to study the accumulation, speciation, and distribution of various heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in sediments from the Yangtze River catchment of Wuhan, China. The potential ecological risks posed by these heavy metals also were estimated. The median concentrations of most heavy metals (As, Cd, Cr, Cu, Ni, Pb, and Zn) were higher than the background values of soils in Wuhan and were beyond the threshold effect level (TEL), implying heavy metal contamination of the sediments. Carbonate-bound Cd and exchangeable Cd, both of which had high bioavailability, were 40.2% and 30.5% of the total for Cd, respectively, demonstrating that Cd poses a high ecological risk in the sediments. The coefficients of the relationship among Pb, Hg, and Cu were greater than 0.797 using correlation analysis, indicating the highly positive correlation among these three elements. Besides, total organic carbon content played an important role in determining the behaviors of heavy metals in sediments. Principal component analysis was used to study the distribution and potential origin of heavy metals. The result suggested three principal components controlling their variability in sediments, which accounted for 36.72% (factor 1: Hg, Cu, and Pb), 28.69% (factor 2: Cr, Zn, and Ni), and 19.45% (factor 3: As and Cd) of the total variance. Overall, 75% of the studied sediment samples afforded relatively low potential ecological risk despite the fact that generally higher concentrations of heavy metals relative to TEL were detected in the sediments.  相似文献   

16.
Soil samples from 16 urban sites in Lianyungang, China were collected and analyzed. A pollution index was used to assess the potential ecological risk of heavy metals and a sequential extraction procedure was used to evaluate the relative distribution of Cu, Zn, Pb, Cd, Cr, and As in exchangeable, carbonate, Fe/Mn oxide, organic/sulfide, and residual fractions. The mobility of heavy metals and urease (URE) activity, alkaline phosphatase (ALP) activity, and invertase (INV) activity of soils was determined. The results showed that the average concentrations of Cu, Zn, Pb, Cd, Cr, and As in Lianyungang soils were much higher than those in the coastal city soil background values of Jiangsu and China. Among the five studied regions (utilities, commercial, industrial, tourism, and roadside), the industrial region had the highest metal concentrations demonstrating that land use had a significant impact on the accumulation of heavy metals in Lianyungang soils. Compared to the other metals, Cd showed the highest ecological risk. According to chemical partitioning, Cu was associated with the organic/sulfides and Pb and Zn were mainly in the carbonate and the Fe/Mn oxide phase. The greatest amounts of Cd were found in exchangeable and carbonate fractions, while Cr and As were mainly in the residual fraction. Cd had the highest mobility of all metals, and the order of mobility (highest to lowest) of heavy metals in Lianyungang soils was Cd > Zn > Pb > Cu > As > Cr. Soil urease activity, alkaline phosphatase activity, and invertase activity varied considerably in different pollution degree sites. Soil enzyme activities had the lowest levels in roadside and industrial regions. Across all the soil data in the five regions, the total Cu, Zn, Pb, Cd, Cr, and As level was negatively correlated with urease activity, alkaline phosphatase activity, and invertase activity, but the relationship was not significant. In the industrial region, alkaline phosphatase activity had significant negative correlations with total Cu, Pb, Cr, Zn, Cd, and heavy metal fractions. This showed that alkaline phosphatase activity was sensitive to heavy metals in heavily contaminated regions, whereas urease and invertase were less affected. The combination of the various methods may offer a powerful analytical technique in the study of heavy metal pollution in street soil.  相似文献   

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