大同市秋季大气气溶胶化学成分及来源解析

采集了大同市2004年9月大气颗粒物样品,应用外束质子激发X荧光(PIXE)方法分析得到了20种元素浓度谱分布。分析结果表明:大气颗粒物样品中绝大多数元素的浓度较低,多数元素呈粗粒模态分布;大同市秋季颗粒物污染较轻。富集因子分析结果表明,大同市秋季大气中颗粒物主要来源于源燃煤尘、土壤尘和工业排放源。     

长春市2006—2007年采暖期大气降尘来源研究

研究长春市2006—2007年采暖期大气降尘的来源,采用电感耦合等离子体法分析降尘中的元素组成,应用富集因子法分析大气降尘中各元素的来源,应用化学质量平衡法分析各污染源的特征元素。结果表明:大气降尘样品中主要元素有As、Mn、Ca、Mg、Fe、Ti、Al、Pb、Zn和Cu;采暖期间长春市区的大气降尘首要来源是燃煤尘,其次是土壤风沙尘;降尘中各污染源特征元素是,建筑尘为Ca元素,土壤风沙尘为Al元素,机动车尾气尘为Pb、Zn元素,燃煤尘为Ti、Mn元素,道路尘为Fe元素;富集因子法和化学质量平衡法在元素的来源分析上具有很好的一致性。     

杭州市道路空气细颗粒物PM_(2.5)元素组成特征

采用微波消解-电感耦合等离子体质谱法及电感耦合等离子体发射光谱法测定2010—2011年杭州市3条典型道路两侧代表秋、冬、春、夏4个季节的细颗粒物PM2.5中22种元素的质量浓度,分析其时空分布规律、特征及来源。结果表明:道路两侧PM2.5中元素含量与道路类型关系不大,呈现夏季小、其余季节大的态势,主要污染元素为Zn、Pb、Cu、Ni;受机动车排放的影响,道路两侧PM2.5呈无机元素含量小、有机元素含量大的特征;Fe、K、Mg、Na、P、Si等土壤元素主要来自机动车行驶引起的道路扬尘;机动车污染特征元素Pb、Zn、Cu、Cd来自相同人为源;机动车污染是道路两侧土壤和灰尘中重金属的主要来源;随着机动车保有量的持续增长,道路两侧PM2.5中Pb仍维持着较高的富集水平。     

不同有色金属矿区的三种植物中五种重金属元素含量的测定

本文对郴州三个有色金属矿区尾砂坝三种同样的先锋植物芒、博落回、荩草中五种重金属的含量进行测定。采用湿法消解植物样品,电热板消解完全消解土壤样品,分别用火焰原子吸收法、石墨炉原子吸收法、氢化物发生器原子吸收法测量其重金属元素Cu、Zn、Pb、Cd、As含量。测量数据显示五种元素的线性关系良好,检出限Cu、Zn为0.0006μg/m L,Pb为0.0024ng/m L,Cd为0.0015ng/m L,As为0.0288ng/m L;精密度在0.7-7.5%之间;回收率在95.00-110.00%之间,都符合测量要求,样品测量数据发现博落回对五种金属元素富集效果较好,转移系数较高,芒对As有较好的富集效果,荩草对Zn、Cd有较好的富集效果。该方法准确度高、简便可行,可作为重金属超富集植物的筛选方法。     

杭州市大气悬浮颗粒PM_(2.5)污染状况及化学组成特征分析

为了解杭州市大气悬浮颗粒物PM2.5污染状况及化学组成特征,2006年在杭州市内布设2个监测点位,按季节进行采样,并对悬浮颗粒物PM2.5中20种元素进行定量研究。结果表明:杭州市区大气中悬浮颗粒物PM2.5的年均质量浓度值为77.5μg/m3,其中S、Si、Ca、K等元素年平均质量浓度大于1.0μg/m3。元素Si、Al、Fe、Mg、V、K、Na、Ti、Mn、Ca、P、Cr、Ni主要来源于地壳,而元素Cl、Cu、Zn、Pb、As、Br、S、Se等主要来源于人为排放源。     

沈阳城区春节期间大气细颗粒元素浓度及其来源

为了解城市春节期间大量燃放烟花爆竹造成的大气污染状况,对沈阳城区进行了大气气溶胶分级采样,对细颗粒样品中41种元素进行了分析。结果表明:春节期间空气中污染物浓度明显高于平时状态,其中燃放烟花爆竹的标识元素Ba、Sr、K等元素浓度非常高;由交通和工业生产产生的污染元素Cd、As、B、Pb、Zn等在细颗粒中也有大量的富集,显示了春节期间除燃放烟花爆竹造成的颗粒物污染外,来自冶炼、餐饮、化学工业以及汽车尾气等人为污染源的释放也占有重要地位。     

矸石山周边土壤环境质量分析与探讨——以豫北某煤矿矸石山为例

本文以河南北部某煤矿矸石山为例,通过在矸石山附近纵向和垂向采集土壤样品测试分析结果,总结了矸石山周边土壤中重金属和有毒有害元素的分布规律,分析探讨了矸石中污染因子的富集和迁移规律。研究结果表明,矸石山周边土壤中金属Cd是主要的潜在生态风险因子,Pb次之,Hg、Cr、As、Cu、Zn、Ni等基本与土壤背景值相同,土壤环境质量基本达到土壤环境质量的二级标准,附近土壤未受污染。Gd元素的富集与降水作用下煤矸石发生风化和淋溶作用有密切关系。     

衡水湖地区气溶胶分布特征的航测研究

利用飞机机载粒子测量系统(PMS)对河北省衡水湖自然保护区上空的大气气溶胶粒子进行观测研究。观测结果表明:下垫面、天气条件、逆温等对气溶胶的分布存在较大的影响;衡水湖上空不同高度的气溶胶平均谱分布均呈现出单峰分布;细粒子谱分布在0.28μm左右处出现峰值;多阶Γ函数对气溶胶粒子谱有较好的拟合效果。     

燃煤与垃圾焚烧飞灰中细颗粒物PM_(2.5)的重金属元素风险评价

为了研究燃煤与垃圾焚烧飞灰中细颗粒物PM_(2.5)所含重金属元素Cu、Zn、Ni、Cr、Pb和Sn的分布特征及潜在风险,利用再悬浮技术采集样品,采用等离子体发射光谱仪与石墨炉检测样品中重金属元素的含量,分别利用富集因子与Hakanson潜在风险指数进行风险评价。结果表明:燃煤飞灰中PM_(2.5)的重金属元素按含量由大到小的顺序为Zn、Pb、Cr、Cu、Ni、Sn,垃圾焚烧飞灰中PM_(2.5)的重金属元素按含量由大到小的顺序为Zn、Pb、Cr、Cu、Sn、Ni;垃圾焚烧过程中的重金属元素富集程度高于燃煤焚烧过程中的;燃煤飞灰中PM_(2.5)的重金属元素含量相对较小,潜在风险较低;垃圾焚烧飞灰中PM_(2.5)的重金属元素含量非常大,潜在风险极高。     

衡阳市冬春季大气颗粒物中重金属的污染评价

采用潜在生态危害指数法和富集因子法,对衡阳市冬春季大气颗粒物中重金属污染进行评价。结果表明:重金属元素的潜在生态危害大小为CdCrPbCuNi,春季冬季,细颗粒物PM~2.5总悬浮颗粒物TSP,Pb、Cd、Cr的潜在生态危害程度均属于极强;重金属的富集程度为:CdCrPbCuNi,PM_2.5TSP;Pb、Cu、Cd冬季富集程度大于春季,Cr和Ni冬季富集程度小于春季;TSP和PM_2.5中重金属的富集系数EF值均大于1,说明重金属的相对富集受到人为活动的影响。     

Characteristics of heavy metals on particles with different sizes from municipal solid waste incineration

Information on the concentration and size distribution of particles in the flue gas streams is essential for selecting and designing particle removal systems. Two municipal solid waste incinerators (MWIs) were selected for conducting flue gas sampling to determine the particulate distribution and heavy metals concentration on particles with different sizes by US EPA Method 5 sampling train and a cascade impactor. In addition, the characteristics of heavy metals contained on particles were investigated via isokinetic sampling of flue gas stream of air pollution control devices (APCDs). The experimental results indicated that average particulate matter (PM) concentrations at APCDs inlet were 2288.2+/-825.9 and 3069.2+/-810. 0mg/Nm(3), while the concentrations of PM at stack were 1.51+/-0.20 and 14.81+/-4.52mg/Nm(3) in MWI-A and MWI-B, respectively. The differential mass size distribution of PM and differential elemental size distribution of Zn, Pb, and Cu in front of APCDs were of bimodal forms. Results indicate that Zn>Pb>Cu in order of mass concentration in each stage. The fine particles represent approximately 70% and the coarse particles account for the rest 30% of total particulate matters collected on eight stages for both incinerators. Zn, Pb and Cu on fine particles account for approximately 80% and those on the coarse particles are less than 20% of the total heavy metals collected on eight stages of the cascade impactor for both incinerators.     

仁怀高粱中重金属元素含量的测定及评价

用原子吸收分光光度法对仁怀市五个乡镇种植的高梁进行了Cu、Zn、Pb、Cd元素含量的测定,采用单项污染指数和综合污染指数法对高粱进行重金属污染评价。结论:该方法灵敏度、准确度高,检出限低,相对标准偏差在0.48-2.88%之间,符合质量控制要求。所检样品中铜、锌含量低于国家食品卫生标准中允许的最低标准要求,高粱中铅、镉含量低于检出限未检出。仁怀市五个乡镇种植的高粱中单项污染指数均很低,其综合污染指数为0.51,因此,所检仁怀市乡镇高粱未受重金属元素污染。     

杭州下沙河道底泥重金属检测及污染分析

检测了杭州下沙河网区18条河道表层底泥重金属Cu、Zn、Pb、Cd、Ni的含量,分析了研究区域内的重金属污染情况,并用潜在生态危害指数法对河道底泥重金属污染情况进行评价,通过聚类分析法分析重金属的空间分布特征.结果表明,Cd污染最严重,超标率为94.44%,平均超标倍数为16.50,Cd的平均潜在生态风险为很高风险,Cu、Zn、Pb、Ni的平均潜在生态风险为低风险,重金属平均综合潜在生态风险属于高风险.重金属聚类分析结果显示Cd、Ni、Pb三种元素相关性显著,应受同一污染源因素影响;采样点聚类分析结果显示下沙河网河道底泥重金属污染分布较为均匀.     

Size distribution and chemical composition of metalliferous stack emissions in the San Roque petroleum refinery complex, southern Spain

We demonstrate that there is great variation in the size range and chemical composition of metalliferous particulate matter (PM) present within petrochemical complex chimney stacks. Cascade impactor PM samples from seven size ranges (17, 14, 5, 2.5, 1.3, 0.67, and 0.33 μm) were collected from inside stacks within the San Roque complex which includes the largest oil refinery in Spain. SEM analysis demonstrates the PM to be mostly carbonaceous and aluminous fly ash and abundant fine metalliferous particles. The metals with the most extreme concentrations averaged over all size ranges were Ni (up to 3295 μg m(-3)), Cr (962 μg m(-3)), V (638 μg m(-3)), Zn (225 μg m(-3)), Mo (91 μg m(-3)), La (865 μg m(-3)), and Co (94 μg m(-3)). Most metal PM are strongly concentrated into the finest fraction (<0.33 μm), although emissions from some processes, such as purified terephthallic acid (PTA) production, show coarser size ranges. The fluid catalytic cracking stack shows high concentrations of La (>200 μg m(-3) in PM(0.67-1.3)), Cr and Ni in a relatively coarse PM size range (0.7-14 μm). Our unique database, directly sampled from chimney stacks, confirms that oil refinery complexes such as San Roque are a potent source of a variety of fine, deeply inhalable metalliferous atmospheric PM emissions.     

Distribution of heavy metals in Lakes Doirani and Kerkini, Northern Greece

The distribution of heavy metals in two lakes of high ecological significance, Doirani and Kerkini, located in Northern Greece was studied. Eight metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were determined in water, total suspended solids, fine and coarse sediments. Moreover, the modified BCR fractionation scheme was employed in sediments and suspended solids to determine soluble, oxidisable, reducible and residual fractions of metals. The Lake Doirani presents higher metal concentrations in aqueous phase than Lake Kerkini; Cd, Cu, Ni, Pb and Zn are above the chronic freshwater quality criteria for aquatic life. In both lakes, Fe and Mn are the most abundant elements in total suspended solids whereas Cd the less abundant. The Lake Kerkini exhibits higher concentrations of all the examined metals in sediments comparing to the Lake Doirani, however the concentrations are lower than the sediment quality guidelines. Cd in sediments is mainly in soluble fraction, Pb and Cu exhibit significant oxidisable fractions whereas, Cr and Fe associated mainly with residual fraction.     

Bioavailability of heavy metals monitoring water, sediments and fish species from a polluted estuary

Concentrations of heavy metals (Cu, Zn, Cd, Pb and As) were measured in water, sediment and two fish species, Sparus aurata and Solea senegalensis, from the estuary of Tinto and Odiel rivers in Huelva (Spain), one of the most metallic polluted estuaries in Europe. As a forward step to understand metal bioavailability and assess the potential impact on aquatic biota, a study of heavy metal speciation of sediments and water were achieved. High levels of total and dissolved Zn and Cu were found in water and high pollution of Zn, Pb, As and Cu were found in sediments. Availability of metals was established as following ranking: Cd>Zn>Cu>Pb in both water and sediment. In addition, the effect of this pollution was studied by evaluation of metal bioaccumulations and correlations obtained between metal levels in fractions of water and sediment and metal levels in fish tissues. High Cu and Zn levels were observed in liver tissue of both species, in according with higher total content and more available metals in water and sediment. Correlations among metal content in tissues and different fractions of metal in water for S. aurata and sediment for S. senegalensis were found.     

多氨基改性蔗渣对水溶液中Pb~(2+)、Zn~(2+)、Cd~(2+)、Cu~(2+)吸附性能的研究

蔗渣经多氨基改性处理后,得到多氨基改性蔗渣吸附剂。考察了多氨基改性蔗渣吸附剂对模拟废水中Pb2+、Zn2+、Cd2+、Cu2+的吸附性能,主要包括吸附时间、溶液pH值和温度对吸附量的影响以及吸附等温式的研究。研究表明,在实验范围内,Pb2+的吸附平衡时间为12h,适宜吸附Pb2+的pH值范围在4～5,Pb2+的最大吸附量为34.96mg/g;Zn2+的吸附平衡时间为20h,适宜吸附Zn2+的pH值在6.2左右,Zn2+的最大吸附容量为2.24mg/g;Cd2+的吸附平衡时间为20h,适宜吸附Cd2+的pH值在5.0左右,Cd2+的最大吸附容量为10.40mg/g;Cu2+的吸附平衡时间为20h;适宜吸附Cu2+的pH值在5.0左右;Cu2+在不同温度下的最大吸附容量为2.60mg/g。多氨基改性蔗渣对Pb2+、Zn2+、Cd2+、Cu2+的吸附均可用Freundlich方程和Langmuir方程描述。     

Powder Microstructure and Overlay Coating Property ofNiCrAlY Alloy

The microstructural features of NiCrAlY alloy powders with different particle size fractions and their effects on the overlay coating property have been investigated. It is shown that the finer (20~30 μm) powder particles experience rapid recalescence and heat extraction to the surroundings resulting in microcellular structure, whereas the coarser (40~50μm) powder particles exhibit a coarse cellular and dendritic mixed structure because of recalescence followed by slow cooling.In addition, it is also indicated that the finer the powder particle sizes, the higher the mechanical property and the metallurgical thermal stability of the overlay coatings deposited by as-atomized powders, which is presumably attributed to the formation of dense fine grain Structure and oxide layer for the fine size fraction of the powders.     

Seasonal trends in coarse and fine particle sources in Delhi by the chemical mass balance receptor model

A study of the source contribution of atmospheric particulate matter and associated heavy metal concentrations using chemical mass balance model Version 8 (CMB8) in coarse and fine size mode has been carried out for the city of Delhi. Urban particles were collected using a five-stage impactor at six sites in three different seasons, viz. winter, summer and monsoon in the year 2001. Five samples from each site in each season were collected. The results obtained indicate the dominance of vehicular pollutants in fine size mode, whilst the contribution in coarse mode to some extent is site specific but largely due to vehicular pollution and, soil and crustal dust. Seasons also play an important role but in coarse size fraction only.