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 187 毫秒
1.
The present study deals with the assessment of ambient air quality with respect to respirable suspended particulate matter (RSPM or PM10 < or = 10 microm) and trace metals (Fe, Zn, Cu, Cr Ni, Cd, Mn and Pb) concentrations in RSPM at five locations of Renukoot, an industrial area of Eastern Uttar Pradesh. The 24 hr mean concentrations of PM10 ranged between 69.3 to 118.9 microg m(-3), which is well within the permissible limit (150 microg m(-3)) of national ambient air quality standards (NAAQS) but found higher than the prescribed annual daily limit of US EPA (50 microg m(-3)). The ambient air was mostly dominated by the Fe and least by the Cd among the metal analysed. Murdhawa, a commercial place influenced by vehicular population, is found to be the most polluted area of Renukoot and Dongia nalla (forest area) the least. The ambient air of Murdhawa is rich in Cu and Ni, indicating contribution of mobile sources. The Rammandir a residential place near the industry, is rich in Cd and Cr suggesting contribution of point sources. The Ni concentration is found to be alarmingly high in the air at all the locations except Dongia nallah, when compared with the EC (European Commission) limit (20 ng m(-3)). The Cd concentration is found to be higher only at Rammandir as compared with the EC limit (5 ng m(-3)). Mean concentrations of Zn, Pb and Mn are found to be almost equal in the ambient air of all the locations, suggesting the significance of sources contributing to presence of these metals. Zn, Cu, Pb and Ni having a significant correlation with PM10 indicate the same source contributing these metals as well as PM10. The present study has focused on the quantitative variation in different metals in the PM10, which is extremely harmful due to their toxic and carcinogenic nature.  相似文献   

2.
王洵 《生态环境》2014,(10):1636-1642
分别运用模拟生物提取法与化学连续提取法对PM10标准参考样品城市源(NIST-1648A)和工业源(BCR-038)中6种重金属(Cd、Co、Cu、Mn、Ni、Pb)质量分数及赋存形态进行分析。其目标是验证2种提取大气固体颗粒物中重金属方法的有效性,并比较2种方法的优缺点,为将来提取PM10中重金属的方法选取提供依据。模拟生物提取法中,使用Gamble溶液模拟人体肺液对 PM10样品进行溶解,实验方法操作较为简单快捷;化学连续提取法中,不同溶解步骤则可确定重金属的不同赋存形态。在需要快速确定 PM10中某种重金属总量时,应优先使用模拟生物提取法。化学连续提取结果表明,城市源PM10中重金属赋存形态分布没有统一规律,工业源PM10中重金属多以残渣态存在。通过对2种来源的PM10样品中重金属生物可利用性分析,城市源的大气颗粒物对人体的毒性更大,其中标准参考样品城市源 PM10中生物可利用性较高的是重金属Cd(BIBio为61.65%±3.45%;BISE为69.02%±3.82%)和Cu,最低的是重金属Co和Pb;标准参考样品工业源PM10中重金属的生物可利用性最高的是Cd(BIBio为27.66%±1.52%;BISE为15.05%±2.13%),而Ni、Co和Pb的生物可利用性较低。  相似文献   

3.
土壤中金属的生物可给性及其动态变化的研究   总被引:2,自引:0,他引:2  
土壤中金属的生物可给性常应用于人体健康风险评价,如能准确地判定土壤中金属在胃肠阶段不同时间的溶出动态,研究者就可以更好地分析其对人体的健康风险。本文采集5种不同地区的重金属污染的土壤,利用改进的PBET方法,分别在胃阶段的20、40、60、80 min以及小肠阶段的1、2、3、4、5 h时取样并分析,探究土壤中8种金属元素(As、Al、Cd、Cr、Fe、Mn、Ni、Pb)的生物可给性和溶出动态,探讨造成金属溶出动态变化的影响因素,对其溶出机理进行初步探究。研究结果表明,Fe、Al的生物可给性较低,并且在胃肠阶段差异较小。与胃阶段相比,土壤中Pb、Cd的生物可给性在小肠阶段明显降低,而As、Mn、Cr、Ni的生物可给性在小肠阶段均升高。升幅最大的两个元素是Ni、Cr,其小肠阶段的平均生物可给性分别升高61.4%、29.9%。在溶出量随时间变化方面,在胃阶段,假定1 h时溶出率为100%。20 min时,土壤中Fe、Ni的平均溶出率较低,分别为59.3%、56.8%,其他6种金属元素的平均溶出率在71.2%~79.5%。As、Cd、Pb的溶出速率是先快后慢,Cr和Ni的溶出速率是先慢后快,而Fe、Mn、Al的溶出速率基本保持不变。在小肠阶段,假定4 h时溶出率为100%。Al、As、Cd、Mn的溶出率基本不变。1 h时,土壤中Cr(土壤A除外)、Ni的平均溶出率最低,分别为31.5%、32.7%,而5 h时,Fe、Cr、Ni的溶出率还在升高。由此可见,土壤中不同金属元素的生物可给性以及溶出动态是有明显差异的。  相似文献   

4.
通过收集大量国内各个地区冶炼场地的最新污染数据,试图从全国尺度范围进行分析,反映中国冶炼行业场地的土壤污染状况。运用污染指数评价法、潜在生态危害指数法和生物毒性评价法,以《土壤环境质量建设用地土壤污染风险管控标准(试行)》(GB 36600—2018)的第一类用地标准值为参比,对土壤中重金属和有机物的污染特征及生态风险进行了分析。单因子指数结果表明:As、Pb、Cd和Ni的浓度均超过了土壤污染风险管制值,其中As的单因子指数为3.80;有机物的评价结果均为清洁。内梅罗指数结果表明:As、Pb、Cd和Ni的土壤污染风险管制值的评价结果为重度污染,且指数均大于35;二苯并(a,h)蒽的评价结果为警戒限,其余有机物的评价结果均为清洁。潜在生态风险评价表明:As具有很强的潜在生态风险,Cd有较强的潜在生态风险,多种元素的综合生态风险评价指数RI为409,具有较强的潜在生态环境风险。空间分布结果表明:南方地区的重金属潜在生态风险远高于西北地区和北方地区,其中潜在生态风险等级为很强的点位主要分布在贵州、湖南和江西等地区,且As和Cd的生态风险因子占据较高的比重。生物毒性评价表明:2-甲基萘、苊烯和二苯并(a,h)蒽将频繁地发生负面生态效应。贵州等南方部分地区的冶炼行业周边土壤已受到As和Cd等重金属的严重污染,应采取有效措施减少排放。该研究可为中国冶炼行业的污染防治提供科学依据和数据支撑。  相似文献   

5.
The objective of this research was to investigate the effects of biosolids on the competitive sorption and lability of the sorbed Cd, Cu, Ni, Pb, and Zn in fluvial and calcareous soils. Competitive sorption isotherms were developed, and the lability of these metals was estimated by DTPA extraction following their sorption. Sorption of all metals was higher in the fluvial than in the calcareous soil. Sorption of Cu and Pb was stronger than that of Cd, Ni, and Zn in all soils. Biosolids application (2.5%) reduced the sorption of all metals especially Cu and Pb (28–43%) in both soils (especially the calcareous soil) at the lower added metal concentrations (50 and 100 mg L?1). However, it increased the sorption of all metals especially Pb and Cu in both soils (especially the calcareous soil; 15.5-fold for Cu) at the higher added concentrations (250 and 300 mg L?1). Nickel showed the highest lability followed by Cd, Zn, and Pb in both soils. Biosolids increased the lability of the sorbed Ni in the fluvial soils at all added concentrations and the lability of Cd, Pb, and Zn at 50 mg L?1, but decreased the lability of Cd, Pb, and Zn at 250 and 300 mg L?1 in both soils. We conclude that at low loading rate (e.g., 50 mg L?1) biosolids treatment might increase the lability and environmental risk of Cd, Cu, Pb, and Zn. However, at high loading rate (e.g., 300 mg L?1) biosolids may be used as an immobilizing agent for Cd, Cu, Pb, Zn and mobilizing agent for Ni.  相似文献   

6.
Twenty trace elements in fine particulate matters (i.e., PM2.5) at urban Chengdu, a southwest megacity of China, were determined to study the characteristics, sources and human health risk of particulate toxic heavy metals. This work mainly focused on eight toxic heavy metal elements (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn). The average concentration of PM2.5 was 165.1 ± 84.7 µg m?3 during the study period, significantly exceeding the National Ambient Air Quality Standard (35 µg m?3 in annual average). The particulate heavy metal pollution was very serious in which Cd and As concentrations in PM2.5 significantly surpassed the WHO standard. The enrichment factor values of heavy metals were typically higher than 10, suggesting that they were mainly influenced by anthropogenic sources. More specifically, the Cr, Mn and Ni were slightly enriched, Cu was highly enriched, while As, Cd, Pb and Zn were severely enriched. The results of correlation analysis showed that Cd may come from metallurgy and mechanical manufacturing emissions, and the other metals were predominately influenced by traffic emissions and coal combustion. The results of health risk assessment indicated that As, Mn and Cd would pose a significant non-carcinogenic health risk to both children and adults, while Cr would cause carcinogenic risk. Other toxic heavy metals were within a safe level.  相似文献   

7.
大气PM2.5中重金属的化学形态分布   总被引:1,自引:0,他引:1  
运用多级连续提取法,对广州市不同季节不同采样高度大气PM2.5中重金属的化学形态和生物有效性进行分析。研究表明,PM2.5中各重金属元素之间的化学形态分布差异较大,Zn、Cd、As、Mn主要分布在F1(可溶态与可交换态)和F2(碳酸盐态、可氧化态与可还原态),绝大部分的Pb以F2存在,Ni和Mo主要分布在F1和F3(有机质、氧化物与硫化物结合态),Cu主要以F2和F3存在,Cr主要分布在F3和F4(残渣态),Co则4种形态平均分布。采样高度对重金属的化学形态分布影响不大,同一采样期内楼顶与地面样品中同一元素的化学形态分布结果比较一致。两个采样季节重金属的形态百分比存在不同程度的变化,2007年春重金属的不稳定态(F1)比例比2006年秋普遍增加,次稳定态(F2、F3)比例减少。在10种重金属中,Cd、Zn、Pb和As的生物有效性系数高(>0.7),属于生物可利用性元素,在环境中的活动性要明显高于其它元素;Mn、Cu、Mo、Co、Ni和Cr元素的生物有效性系数值在0.2~0.6之间,属于潜在生物有效性元素,在环境中比较稳定。  相似文献   

8.
This work presents the results of the determination of concentrations of the trace metals Ni, Zn, Mn, Pb, Cd, Cr, Co, Cu, and Fe in eggs from farms in Southern Nigeria. The mean concentrations (µg?g?1 fresh weight) ranged from 0.6 to 1.2 for Ni, 3.1 to 8.9 for Zn, 0.45 to 0.65 for Mn, 0.4 to 1.2 for Pb, <0.09 to 0.3 for Cr, 0.1 to 0.3 for Cd, 0.26 to 0.34 for Co, 0.9 to 1.2 for Cu and 19.5 to 24.0 for Fe. The concentrations and estimated dietary intakes of these metals were below the respective statutory limits. The Target Hazard Quotient (THQ) values for the individual metals in all zones are less than 1, i.e., within safe levels. The combined THQ values for the different zones were greater than 1but less than 2, with a significant contribution of cobalt.  相似文献   

9.
氧化与还原条件下水稻土重金属形态特征的对比   总被引:8,自引:1,他引:7  
还原状态下的水稻土被风干处理后氧化还原等性质发生明显变化,对重金属的形态特征产生影响,进而影响对作物有效性的评价.利用BCR连续萃取法研究了张家港市南部不同pH水稻土在还原和氧化条件下Cu、Pb、Ni和Cd的形态变化状况.结果显示,氧化还原对重金属形态分配具有显著影响,而pH对Ni在还原状态下的形态分配有显著影响,对Cu、Pb和Cd形态分布影响不显著.样品经风干氧化处理后,氧化物结合态重金属均表现为不同程度的降低;Cu残渣态比例增加25%,氧化物结合态和有机结合态比例有所降低;Pb有机结合态比例增加33%,残渣态减少33%,酸可提取态和氧化物结合态变化不大;Ni受氧化还原条件影响更为强烈,表现为酸可提取态所占比例降低超过25%,氧化物结合态亦明显降低,残渣态提高超过60%;对Cd的影响主要表现为有机结合态所占比例降低约15%,残渣态提高约35%,酸可提取态和氧化物结合态变化不明显.氧化状态下的重金属形态并不是重金属在田间的真实状况,可能高估了Pb,低估Cu、Ni和Cd重金属在土壤中的危害性.  相似文献   

10.

Intense mining, smelting, and tailing activities of polymetallic ore deposits have affected the environment in Nandan County, Guangxi, China. Samples of particulates with aerodynamic diameters low or equal 10 μm (PM10) were collected in Nandan County to investigate the concentrations of and health risks posed by 17 metals and metalloids in the PM10. The metal and metalloid concentrations were lower than those found in other industrial cities. The mean Cr concentration was 7.48 ng/m3. Significant higher metal and metalloid concentrations were found in PM10 from mining areas (Dachang and Chehe) than from the control area (Liuzhai) (p < 0.05). Principal component analysis indicated that the main sources of Ba, Co, Cr, Fe, K, Mg, Mo, Na, and Sr were resuspension of the soil produced through mineral erosion, the main sources of As, Cd, Cu, Pb, Sb, and Zn were smelting and mining activities, and the main source of Ni was fossil fuel combustion. Higher non-carcinogenic and carcinogenic risks were posed in Dachang and Chehe than in Liuzhai. The non-carcinogenic risks posed to adults and children by individual metals and metalloids in PM10 at all the sites were low, but the non-carcinogenic risks posed to children by all the metals and metalloids together exceeded the safe level (i.e., risk value > 1). The carcinogenic risks posed by Cd, Ni, and Pb were negligible at all sites, while As, Co, and Cr posed potential carcinogenic risks to the residents.

  相似文献   

11.
Increased risk of ill-health and diseases has been associated with employment in the ferro-alloy factory. Since measurement of transition metals in human blood and hair along with respective exposure rates, provides a means of assessing individual risk, it has been the most important part of the study. In the study majority of the elements in the transition series, such as, vanadium (V), chromium (Cr), iron (Fe), manganese (Mn), cobalt, (Co) nickel (Ni), copper (Cu), zinc (Zn), molybdenum (Mo) and cadmium (Cd) were considered which are randomly emitted from the source, that is, manganese ore (used during ferro-alloy manufacturing process). The commonly available transition, metals, observed in biological samples of ferro-alloy workers, were found to be Fe, Zn, Co, Ni, Cu, Cr, Cd, V Mn and Mo in blood, while in hair, Mn, Fe, Zn, Co, Ni, Cu, Cr, Cd, V and Mo were present in decreasing order Surveillance of bio-concentration of these metals in workers, exposed to close proximity of the coke-ovens and smelting furnaces, revealed that the workers were prone to several physical disorders.  相似文献   

12.
根际环境产生的柠檬酸等小分子有机酸可能影响重金属的溶出效应.本文研究了4种重金属Cd、Pb、Cu、Ni及柠檬酸在针铁矿表面的三元体系吸附行为,结果发现柠檬酸促进了4种重金属酸性条件下在针铁矿表面的吸附量,而Cu、Ni促进了柠檬酸碱性条件下的吸附.结合红外光谱图发现,重金属-柠檬酸-针铁矿主要存在以下2种三元体系形态,即以柠檬酸为"桥键"的≡Fe2CitMe形态和以重金属为"桥键"的(≡FeOH)2MeCit形态.采用电荷分配-多位点表面配合(CD-MUSIC)模型成功预测了的三元体系重金属及柠檬酸在针铁矿表面的吸附行为,模型结果发现柠檬酸的存在显著改变了重金属的吸附形态,其中≡Fe2CitMe为Cd、Pb、Ni三元体系中酸性条件下的主要形态,(≡FeOH)2CuCit为Cu的主要形态.研究补充完善了根际环境的土壤形态模型数据库,为预测重金属的溶出及生物有效性的模型研究提供了基础数据.  相似文献   

13.
孙敏  唐莹  郝亚婷  季宏兵 《环境化学》2021,40(3):678-686
酸雨对露天粉煤灰堆积场的淋滤作用导致周围环境产生重金属污染是一种广泛现象.为研究酸雨对贵阳市水源地红枫湖周边一大型粉煤灰堆积场的重金属迁移影响,本文以这一粉煤灰堆积场为研究对象,通过静态淋溶实验探讨了粉煤灰中Cr、Ni、CU、Zn、AS、Cd、Pb等7种重金属元素的含量、存在形态、淋溶时间、堆积时间、粒度对重金属溶出规律的影响.结果表明,粉煤灰中Ni、Cu、Zn、Pb、As和Cd等6种重金属的含量随堆积时间增加而增大,Cr含量变化与上述反之;在淋溶实验中,堆积时间的增加使Cr、Ni、Cu和Zn重金属元素的可溶态减小;在淋溶第28—48天期间,Cr、Ni和Cu元素溶出浓度降低的粒度顺序为细粒度>中粒度和粗粒度、Cd元素溶出浓度降低的粒度顺序为中粒度>粗粒度>细粒度.本研究对红枫湖水源地和周边地下水的重金属防控提供一定的参考依据.  相似文献   

14.

Rapid industrialization and urbanization have contaminated air and soil by heavy metals and metalloids from biogenic, geogenic and anthropogenic sources in many areas of the world, either directly or indirectly. A case study was conducted in three different microenvironments, i.e., residential sites, official sites and official sites; for each sites, we choose two different locations to examine the elemental concentration in fine particulate matter and soil and health risk assessment. The concentration values of heavy metals and metalloid in the air and soil in the Agra region were measured using inductively coupled plasma-atomic emission spectrophotometry. The exposure factor and health risk assessment for carcinogenic and non-carcinogenic effects due to heavy metals and metalloid contaminants have been calculated for both children and adults by following the methodology prescribed by USEPA. For the elements As, Cr, Cd, Ni and Pb selected for the carcinogenic health risk assessment, the calculated results lie above the threshold ranges. We observed the lifetime exposure to heavy metals through mainly three pathways, ingestion, inhalation and dermal contact of soil and air from that particular area. Therefore, the overall hazard quotient (HQ) values for children are more than that of adults. The assessment of health risk signifies that there were mainly three exposure pathways for people: ingested, dermal contact and inhalation. The major exposure pathway of heavy metals to both children and adults is ingestion. The values of HQ are higher than the safe level (=1), indicating a high risk exists in present condition. Meanwhile, HQs value for children is higher than that for adults, indicating that children have higher potential health risk than adults in this region.

  相似文献   

15.
The BCR (European Communities Bureau of Reference) three-step sequential extraction procedure was applied to fractionate heavy metals in the sediment of Taihu Lake. For the determination of total metal concentration of the sediments, sample digestion was achieved by using HF/H2O2/HNO3 (2/1/1) acid mixture in a microwave-irradiated closed vessel system. The concentrations of Cd, Ni, Cr, Zn, Cu and Pb in various extracts solutions were analyzed by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The results obtained from the BCR three-step sequential extraction indicated relatively high mobility of Zn, Cu, Pb and Ni in the sediments while Cd and Cr were poorly mobile. Enrichment of heavy metals was found in the sediments collected in the northern parts of Taihu Lake. In the sediments collected in the southern and western sides of the Lake, heavy metal concentrations were relatively low. The relationship between total organic carbon (TOC) and heavy metals concentrations in the sediments is discussed.  相似文献   

16.
运用多级连续提取法,对广州市不同季节不同采样高度大气PM2.5中重金属的化学形态和生物有效性进行分析。研究表明,PM2.5中各重金属元素之间的化学形态分布差异较大,Zn、Cd、As、Mn主要分布在F1(可溶态与可交换态)和F2(碳酸盐态、可氧化态与可还原态),绝大部分的Pb以F2存在,Ni和Mo主要分布在F1和F3(有机质、氧化物与硫化物结合态),Cu主要以F2和F3存在,Cr主要分布在F3和F4(残渣态),Co则4种形态平均分布。采样高度对重金属的化学形态分布影响不大,同一采样期内楼顶与地面样品中同一元素的化学形态分布结果比较一致。两个采样季节重金属的形态百分比存在不同程度的变化,2007年春重金属的不稳定态(F1)比例比2006年秋普遍增加,次稳定态(F2、F3)比例减少。在10种重金属中,Cd、Zn、Pb和As的生物有效性系数高(〉0.7),属于生物可利用性元素,在环境中的活动性要明显高于其它元素;Mn、Cu、Mo、Co、Ni和Cr元素的生物有效性系数值在0.2~0.6之间,属于潜在生物有效性元素,在环境中比较稳定。  相似文献   

17.
南京城市土壤重金属含量及空间分布特征   总被引:13,自引:0,他引:13  
研究了南京城市土壤重金属含量、来源及空间分布特征。结果表明,南京城市土壤中V、Mn、Co、Ni、Cr污染不明显,但受到了不同程度的Cu、Pb、Zn、Sb、Hg、Cd污染,其中Hg污染比较严重。V、Mn、Co、Ni、Cr含量之间均呈极显著正相父;Cu、Pb、Zn、Sb、Hg、Cd含量之间也均呈极显著正相关。南京城市土壤V、Mn、Co、Ni、Cr主要继承了原土物质;Hg、Cd、Pb主要来源于城市燃煤、机动车尾气及工厂排放粉尘;Sb主要来源于机动车尾气和工厂排放粉尘。南京城市土壤Hg、Cd、Pb、Sb含量空间分布规律非常相似,均表现为外围向市中心有逐渐增加的趋势,并且在新街口—鼓楼、梅山硫铁矿形成异常高值的岛状、环状区域。  相似文献   

18.
滩涂围垦土壤是重金属等难降解污染物的主要最终归宿场所之一,其重金属的解吸将影响重金属的迁移性、生物有效性和潜在毒性,研究重金属的解吸对土壤污染评价、修复及环境容量预测至关重要.研究了烟气脱硫石膏对广州市南沙滩涂围垦土壤重金属的解吸效果,并分析了烟气脱硫石膏对重金属形态的影响.在离心管中称取20.0 g过0.25mm筛土样,加入20 mL水和不同量的烟气脱硫石膏,在室温下于恒温振荡器振荡,风干研碎后用原子吸收分光光度法测定重金属全量,并用Tessier连续提取法研究了处理前后重金属形态变化.研究结果表明,随着脱硫石膏施用量的增加,经过振荡离心后的滩涂围垦土壤中重金属质量分数先急剧下降,之后变化趋于平缓.与原土相比各重金属最大解吸率分别为:Cd 30.38%,Cu17.73%,Ni 15.00%,Zn 14.19%,Pb 9.46%,Cr 8.89%.比较处理前后重金属的形态变化,发现各重金属的可交换态解吸率均达50%以上,并且重金属碳酸盐结合态质量分数也有减少.说明烟气脱硫石膏能降低土壤对重金属的吸附,经振荡离心后能降低土壤中重金属的毒性和生物可利用性.  相似文献   

19.
The BCR (European Communities Bureau of Reference) three-step sequential extraction procedure was applied to fractionate heavy metals in the sediment of Taihu Lake. For the determination of total metal concentration of the sediments, sample digestion was achieved by using HF/H2O2/HNO3(2/1/1) acid mixture in a microwave-irradiated closed vessel system. The concentrations of Cd, Ni, Cr, Zn, Cu and Pb in various extracts solutions were analyzed by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The results obtained from the BCR three-step sequential extraction indicated relatively high mobility of Zn, Cu, Pb and Ni in the sediments while Cd and Cr were poorly mobile. Enrichment of heavy metals was found in the sediments collected in the northern parts of Taihu Lake. In the sediments collected in the southern and western sides of the Lake, heavy metal concentrations were relatively low. The relationship between total organic carbon (TOC) and heavy metals concentrations in the sediments is discussed.  相似文献   

20.
The fate and partitioning of heavy metals (including Hg, Cd, Pb, Zn, As, Cr, Ni, and Cu) from MSW incinerators located in Taiwan were determined. Results of stack sampling indicate that most Hg and As (more than 80%) exists in the gas phase while other metals partition differently among bottom ash, fly ash, and flue gases. Removal efficiencies of existing air pollution control devices for Hg and As are lower (about 70%) than other metals. Bottom ash contains higher concentration of Cd compared with European incinerators. In addition, strong enrichment of Cd on fly ash particles is observed.  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