土壤重金属X射线荧光光谱非标样测试方法研究

采用粉末压片制样,用X射线荧光光谱非标样测试方法测定土壤中Ti、V、Cr、Mn、Fe、Ni、Cu、Zn、Ga、As、Cd、Sn、Sb、Pb、Hg等15种重金属元素。研究了样品制备方法和元素测量条件等影响测试准确度的因素。结果表明此方法不需对固体样品进行消化处理,无需制备标准样片,快速、简便、效率高,是一种非破坏性的分析方法,方法的检出限、准确度和精密度基本能够满足土壤中有毒有害重金属的快速筛查要求。     

Application of portable X-ray fluorescence (pXRF) for heavy metal analysis of soils in crop fields near abandoned mine sites

To get representative soil samples, a sampling method was verified for crop fields in the vicinity of abandoned mine sites. Application of appropriate sampling or analytical methods is very important as it affects the costs, time, and accuracy of the refined investigation of soil contamination. Two-time sampling for each crop field was conducted to verify the reproducibility of a zigzag method for soil sampling. The soil analysis using a portable X-ray fluorescence (pXRF) device was conducted to measure concentrations of metal species in soils, and its results were compared to the extracted concentrations by the Korean Standard Test (KST) for soils. As a result, the determination coefficient (R ²) of linear regression analysis for data obtained by ex situ precise measurement or in situ field screening using pXRF was closely related with the ratio of the extracted concentration by KST to interference-free detection limits (IFDL) of pXRF (designated as KST/IFDL). As the specific metal species had a higher ratio of KST/IFDL, its R ² was even higher in the field screening tests. However, the slopes of linear regression analysis for most metal species extracted by aqua-regia were close to 1.0 so that extracted concentrations by aqua-regia were similar to the analytical values obtained by pXRF, whereas extraction using a weak acid (0.1 M HCl) had different slopes for soils contaminated with different ranges of concentrations of metal species. Especially Zn showed not only high ratios of KST/IFDL because of aqua regia extraction, but also high determination coefficients. Because of its simple, rapid, and accurate capacities for metal analysis, the pXRF analysis showed high applicability in ex situ precise measurements or in situ field screening of metal analysis. In terms of applicability for regulation, especially in situ pXRF field screening with the zigzag method could be effectively applied to achieve an economical survey by determining hot spots or non-contaminated areas if aqua-regia was applied as the extracting agent in the KST for soils.     

几种植物处理含重金属废水的适应性研究

试验采用蕹菜、油菜、美人蕉、水葫芦、水花生、水浮莲6种适应人工湿地的植物，在水培情况下研究了它们对Hg、Cd、Pb、Cr、Cu、Zn6种重金属的适应性，以综合考虑了植物的适水性与对重金属耐性的生物量为指标，得出了植物对6种重金属模拟废水综合耐性由强到弱的排序为美人蕉→水葫芦→油菜→水浮莲→蕹菜→水花生。不同植物对于其中一种重金属的单一耐性也有差异，美人蕉对Cr、Hg、Zn耐性较强，水浮莲对Pb、Cu、Cd耐性较强。植物对重金属的综合耐性和单一耐性的试验结果可为湿地处理含重金属废水提供参考。     

Frequency of abnormal heavy metal blood levels in Wegener's granulomatosis

Previous studies suggested environmental exposures, including mercury (Hg) and lead (Pb), may be related to Wegener's granulomatosis. In this study, investigations were extended to include the measurement of heavy metals in blood samples from patients diagnosed with Wegener's. Diagnosis was confirmed by using the 1990 Classification Criteria for Wegener's granulomatosis established by the American College of Rheumatology (ACR). Using commercial lab testing, whole blood heavy metal screenings were obtained from patients, and results were then compared with validated subject self-report questionnaire estimates of exposure. Thirty-eight Wegener's patients were enrolled; 10 of the 38 exhibited abnormal lab values. In those 10 subjects 3 had elevated nickel (Ni), 7 with increased cobalt (Co), 3 with higher manganese, 1 with elevated copper, and 1 with increased Hg. Overall, the questionnaire results did not correlate with the blood heavy metal analysis. Approximately 26% of Wegener's subjects in this study displayed abnormal heavy metal levels. These findings are likely underestimates since blood levels are an insensitive means for assessing total body burden of heavy metals. From these preliminary studies it appears that elevated Co is a common finding in Wegener's patients but Ni and Hg were also found to be increased. The proportion of patients with abnormal heavy metal levels is more than expected by chance alone. In order to yield more definitive results, further analysis is needed with a larger data set, more controls and more sensitive measurements (hair, urine, or nail samples).     

城市工业用煤X荧光分析及重金属元素污染研究

燃煤是成都市重金属污染的一个重要来源,目前对成都燃煤中重金属元素含量与城市环境污染的相关性研究相对较少。文章以成都市城东工业区为研究对象,利用X荧光分析方法对煤样、煤渣、煤灰、表层土、深层土4种重金属元素进行定量分析,探讨了燃煤中重金属含量与城市土壤重金属污染的相关关系。结果表明,(1)成都市工业用煤原产地煤样重金属元素的含量不尽相同,因此,企业需合理选择煤源。(2)土壤重金属元素污染与工业用煤正相关,工业用煤中有害元素含量较高的对当地土壤的污染也比较严重,相反工业用煤中含量较少的元素在土壤中含量也较小。(3)热电厂燃煤对城市重金属污染的行为属性表现为,Pb属于直接污染大气和土壤,而Cu、Zn、Cr富集在煤渣样、煤灰样中在后期造成对城市土壤的污染。     

Bioremediation of heavy metal contaminated medium using Lemna minor,Daphnia magna and their consortium

Single, dual and triple mixtures of totally seven different mixture combinations of the metals Al, Ba and Fe were examined in Lemna minor (L) culture, Daphnia magna (D) culture and in a consortium culture consisting of L. minor and D. magna. In this study: (a) differences in removed metal proportions at the end of 24 and 48?h, (b) differences in removed metal amounts due to cultures, (c) differences in the removed proportions of a metal in distinct mediums and (d) removal correlation of the metals due to cultures were investigated. The study results showed that among the metals Al, Ba and Fe, Al has the most toxic effect on organisms involved in this study. Although similar toxicity results of Al and Fe on test groups were observed, Ba gave different toxicity results on test groups. An overview of the bioremediation results indicates that L. minor removes the metals Al and Fe more successfully than Ba. Different mixture combinations of metals performed dissimilar removal results in the same cultures. According to the correlations analysis for the metals Ba and Fe, a high correlation was recorded between the consortium group and test groups containing only D. magna, r?=?0.88, r?=?0.91, respectively.     

Relations between heavy metal levels in soil,detritophagous and phytophagous invertebrates

Heavy metal (HM) levels in soil samples taken from surface soil horizon (up to 30 cm depth) and in the bodies of two invertebrate groups (earthworms as detritophagous and snails as phytophagous) were investigated during the vegetation period of 1993 in Central Moravia. Within the frame of large scale monitoring the above samples were taken repeatedly in ten selected habitats, mostly Protected Landscape Areas (PLA) and forests, and heavy metal levels of seven elements (Cd, Pb, Cr, Mn, Cu, Zn, Fe) were estimated by AAS after laboratory treatment. In soil samples three HM forms (fixed, soluble and available) were differentiated. Results indicated that the individual HM are distributed in a characteristic way both in soil and in invertebrate bodies. A relative comparison indicated that soil is the main depot for Pb, Cr, Mn and Fe, whereas biomass accumulates mainly Zn, Cu and Cd (related to kg dry matter). Characteristic differences were also found in the HM levels between detritophagous (earthworms) and phytophagous (snails) invertebrates. Elevated HM levels in several Protected Landscape Areas should be considered as warning symptoms.     

钢铁工业遗留场地土壤重金属洗脱剂筛选研究

土壤重金属污染限制了工业遗留场地再利用,通过振荡试验考察了HCl、HNO3和EDTA对工业遗留场地土壤中超标重金属Pb、Zn、Cd和As的洗脱效果。结果表明：土壤Pb、Zn、Cd、As的脱除效果均随洗脱剂浓度增加而增加;HCl、HNO3和EDTA等3种洗脱剂浓度分别为0.5、0.5和0.1 mol.L-1时,土壤Pb、Cd质量分数可降低至场地安全再利用的控制标准以内（分别为140 mg.kg-1、1mg.kg-1）;洗脱剂浓度分别增至2、2和0.2 mol.L-1时,土壤Pb、Cd质量分数继续降低,Zn、As质量分数有大幅降低但没有达到其相应的场地安全控制标准（分别为200、20 mg.kg-1）;与EDTA相比,HCl在低浓度时的重金属脱除效果较差,但HCl浓度增加对重金属脱除率的提高效果更为明显;洗脱液pH值（7.88~0.15）与重金属脱除率均呈显著负相关且与As的负相关系数最小,说明洗脱液pH值变化对As去除的影响相对较小;与HCl和HNO3相比,EDTA洗脱液pH值与Pb脱除率之间的负相关系数较大,与Zn、Cd、As脱除率之间的负相关系数较较小,说明EDTA洗脱液pH值变化更易对Pb的去除产生影响。     

吹扫捕集/气相色谱-原子荧光光度法测定土壤和沉积物中烷基汞

本文将原子荧光光谱检测技术与吹扫捕集/气相色谱检测技术联用,结合优化的碱性法消解前处理技术,建立了碱性法消解-吹扫捕集/气相色谱-原子荧光光谱(PT-GC-AFS)联用技术测定土壤和沉积物中烷基汞含量的方法,能够在一次分析中同时获得样品中甲基汞和乙基汞的含量.本文分别用酸性法和碱性法处理了沉积物标准样品ERM-CC580、沉积物实际样品和土壤实际样品,重点比较了本方法提出的碱性法消解和使用率较高的酸性法消解两种前处理方式.采用本方法处理实际样品进行了色谱分离研究,对低浓度的实际土壤样品进行了检出限实验,用3种不同浓度的沉积物和3种不同浓度的土壤样品验证了精密度,对沉积物标准参考物质ERM-CC580进行了测定,并用两种实际土壤样品和两种实际沉积物样品进行了加标回收率试验.实验表明,碱性法消解精密度和准确度优于酸性法消解,且步骤少、耗时短,使用的试剂种类少、毒性小,方法稳定性高、可操作性强,适用于分析测试实验室大量土壤/沉积物样品的烷基汞测定.采用碱性法消解土壤/沉积物样品,目标物实现完全分离,甲基汞、乙基汞的线性相关系数分别为0.9999、1.0000,最低检出限分别为0.02μg·kg~(-1)、0.10μg·kg~(-1)(取样量为0.50 g),样品分析甲基汞、乙基汞的RSD范围分别为1.0%—4.7%、2.5%—6.0%,加标回收率范围分别为85.1%—109%、90.3%—96.3%.     

混酸微波辅助萃取ICP-MS测定不同性质土壤中的重金属元素

比较了硝酸(HNO3)、硝酸-盐酸(HNO3∶HCl=3∶1)、硝酸-盐酸-双氧水(HNO3∶HCl∶H2O2=3∶1∶1)和硝酸-盐酸-高氯酸(HNO3∶HCl∶HCl O4=3∶1∶1)等4种消解液对土壤中铅(Pb)、镉(Cd)、砷(As)、铬(Cr)、镍(Ni)、铜(Cu)和锌(Zn)等7种重金属元素的萃取效率.结果表明,硝酸-盐酸-高氯酸混合液的萃取效果最好,硝酸-盐酸混合液次之.通过对6种土壤标准物质的分析发现,除了Cr之外,其他重金属元素在土壤中的混酸微波可提取态含量与总含量接近.土壤中的Cr有一部分是以铬铁矿的形式存在,在环境中相对较为稳定,采用混酸微波可提取态的Cr来评估其对环境的危害能够获得更加准确的结果.重金属与土壤的结合强弱与成土母质相关,冲积母质的土壤中Pb、Zn和Cu的结合较强,萃取相对较难,Cd、Ni和As与土壤的结合强弱则与成土母质关系不大.采用最优的消解液萃取矿区河流底泥和土壤中的重金属,ICP-MS分析结果表明,底泥中重金属含量较高,应为尾砂冲积而成,矿区周边的土壤也受到不同程度重金属的污染.     

Relationship between plant biodiversity and heavy metal bioavailability in grasslands overlying an abandoned mine

Abandoned metal mines in the Sierra de Guadarrama, Madrid, Spain, are often located in areas of high ecological value. This is true of an abandoned barium mine situated in the heart of a bird sanctuary. Today the area sustains grasslands, interspersed with oakwood formations of Quercus ilex and heywood scrub (Retama sphaerocarpa L.), used by cattle, sheep and wild animals. Our study was designed to establish a relationship between the plant biodiversity of these grasslands and the bioavailability of heavy metals in the topsoil layer of this abandoned mine. We conducted soil chemical analyses and performed a greenhouse evaluation of the effects of different soil heavy metal concentrations on biodiversity. The greenhouse bioassays were run for 6 months using soil samples obtained from the mine polluted with heavy metals (Cu, Zn, Pb and Cd) and from a control pasture. Soil heavy metal and Na concentrations, along with the pH, had intense negative effects on plant biodiversity, as determined through changes in the Shannon index and species richness. Numbers of grasses, legumes, and composites were reduced, whilst other species (including ruderals) were affected to a lesser extent. Zinc had the greatest effect on biodiversity, followed by Cd and Cu. When we compared the sensitivity of the biodiversity indicators to the different metal content variables, pseudototal metal concentrations determined by X-ray fluorescence (XRF) were the most sensitive, followed by available and soluble metal contents. Worse correlations between biodiversity variables and metal variables were shown by pseudototal contents obtained by plasma emission spectroscopy (ICP-OES). Our results highlight the importance of using as many different indicators as possible to reliably assess the response shown by plants to heavy metal soil pollution.     

Introducing a new metal accumulator plant and the evaluation of its ability in removing heavy metals

A field study was conducted in a dried waste pool of a lead (Pb) mine in Arak (Iran) to find the accumulator plant(s) and to evaluate the amount of metal bioaccumulation in the root and shoot portion of the naturally growing vegetation. Concentrations of heavy metals were determined both in the soil and the plants that were grown in the dried waste pool. The concentrations of total Cu, Zn, Pb, and Ni in the waste pool were found to be higher than the natural soil and the toxic levels. The results showed that six dominant vegetations, namely, Centaurea virgata, Eleagnum angustifolia, Euphorbia macroclada, Gundelia tournefortii, Reseda lutea, and Scariola orientalis accumulated heavy metals. Based on the results, it was concluded that E. macroclada belonging to Euphorbiaceae is the best Pb accumulator and also a good accumulator for Zn, Cu, and Ni. The bioaccumulation ability of E. macroclada was evaluated in experimental pots. The study showed that the amount of heavy metals in polluted soils decreased several times during two years of phytoremediation. The accumulation of metal in the root, leaves, and shoot portions of E. macroclada varied significantly, but all the concentrations were within the toxic limits. Based on the obtained data, E. macroclada is an effective accumulator plant for soil detoxification and phytoremediation in critical conditions.     

基于PCR-DGGE的重金属污染土壤微生物种群指纹分析

采用变性梯度凝胶电泳（DGGE）分析方法,研究沈阳市细河沿岸重金属污染土壤中微生物结构多样性、种群丰富度及种群结构的动态变化规律。结果表明：直接从土壤中抽提总DNA,对16SrRNAV3可变区序列进行扩增,DGGE指纹图谱分析,微生物种群结构和变化规律明显,同时也表现为重金属污染程度越重,多样性指数越低;其中细河底泥重金属含量严重超标,多样性指数最低。经方差分析,重金属污染情况与Shannon-wiener多样性指数呈负相关,其中重金属污染对微生物的均匀度指数影响最显著,并且锌污染对其影响最大为-0.985。表明PCR-DGGE技术可以用于污染环境下微生物多样性研究,也为污染环境下土壤微生物多样性研究提供了新的实验方法与依据。     

翅碱蓬对盐碱湿地重金属污染消减作用

为探究翅碱蓬对盐碱湿地重金属污染的消减作用和生态修复能力,采用现场监测与高盐水培试验相结合的方法,测定不同浓度Zn2+、Cu2+和Pb2+混合污染下,翅碱蓬对重金属的吸收消减作用.结果表明,在高盐环境下,翅碱蓬对重金属锌、铜和铅均具有消减作用,生物富集系数BCFSh-Zn＞BCFSh-Cu＞BCFSh-Pb.当重金属离...     

荧光光谱法快速检测土壤中荧光烃类污染物

探讨了正己烷、石油醚及二氯甲烷∶正己烷(1∶2,体积比)混和液三种溶剂浸泡或超声波萃取与荧光光谱相结合测定土壤中荧光烃类污染物的方法,并为了验证方法有效性,对典型煤矿区93个土壤样品中的荧光烃类进行了快速检测。结果表明,采用二氯甲烷∶正己烷(1∶2,体积比)混和液超声波萃取土壤中荧光烃类,耗时短,萃取能力较强。对于具有大量土壤样品的研究区域,超声波萃取与荧光光谱法相结合可大大缩短土壤样品中总荧光烃类污染物的检测时间,进而可快速获知某一研究区内土壤环境中荧光烃类污染物的空间分异规律及相对污染程度,具有一定的应用价值。     

Biotic contexts alter metal sequestration and AMF effects on plant growth in soils polluted with heavy metals

Investigating how arbuscular mycorrhizal fungi (AMF)-plant interactions vary with edaphic conditions provides an opportunity to test the context-dependency of interspecific interactions. The relationship between AMF and their host plants in the context of other soil microbes was studied along a gradient of heavy metal contamination originating at the site of zinc smelters that operated for a century. The site is currently under restoration. Native C3 grasses have reestablished, and C4 grasses native to the region but not the site were introduced. Interactions involving the native mycorrhizal fungi, non-mycorrhizal soil microbes, soil, one C3 grass (Deschampsia flexuosa), and one C4 grass (Sorghastrum nutans) were investigated using soils from the two extremes of the contamination gradient in a full factorial greenhouse experiment. After 12 weeks, plant biomass and root colonization by AMF and non-mycorrhizal microbes were measured. Plants from both species grew much larger in soil from low-contaminated (LC) origin than high-contaminated (HC) origin. For S. nutans, the addition of a non-AMF soil microbial wash of either origin increased the efficacy of AMF from LC soils but decreased the efficacy of AMF from HC soils in promoting plant growth. Furthermore, there was high mortality of S. nutans in HC soil, where plants with AMF from HC died sooner. For D. flexuosa, plant biomass did not vary with AMF source or the microbial wash treatment or their interaction. While AMF origin did not affect root colonization of D. flexuosa by AMF, the presence and origin of AMF did affect the number of non-mycorrhizal (NMF) morphotypes and NMF root colonization. Adding non-AMF soil biota reduced Zn concentrations in shoots of D. flexuosa. Thus the non-AMF biotic context affected heavy metal sequestration and associated NMF in D. flexuosa, and it interacted with AMF to affect plant biomass in S. nutans. Our results should be useful for improving our basic ecological understanding of the context-dependency of plant-soil interactions and are potentially important in restoration of heavy-metal-contaminated sites.     

桂北锰矿废弃地主要植物种类调查及土壤重金属污染评价

采用样方法和实地勘查法调查了桂北荔浦锰矿区废弃地自然定居和人工种植的植物,并且对8个区的主要植物及其土壤重金属含量进行了分类、测试。并采用污染指数评价法对矿区废弃地土壤重金属的污染程度进行了评价。结果表明,白茅(Imperata cylindrica)、马唐(Digitaria sanguinalis)、飞蓬(Erigeron acer)、苍耳(Xanthium sibiricum)、耳草(Hedyotisauricularia)对重金属有较强的耐性,而且能适应废弃地的不良环境,可作为锰矿废弃地生态恢复的先锋植物;用3种不同的背景值对废弃地土壤重金属污染程度的评价结果是一致的,除Pb外,5种重金属元素单项污染指数均大于2,表示被污染,其中以Mn、Zn、Cd污染最为严重。锰矿废弃地人工复垦采用典型的农业恢复模式,以种植果树和经济作物为主,果实中Cr、Cd的含量均超过食品卫生限量标准,因此矿山恢复的早期不宜直接种植果树和食用经济作物。以上研究结果可为锰矿废弃地的生态恢复和植被重建提供科学依据。     

平原典型垃圾焚烧厂周边土壤重金属分布特征及污染评价

随着固体废弃物的增加,垃圾焚烧逐步成为城市垃圾处理应用一个较为理想可行的选择。垃圾焚烧不仅可以回收能源,且相对其他处理方式其减量效果显著。垃圾焚烧厂排出的尾气中的某些特定重金属可以通过大气干湿沉降进入土壤。采用XRF 荧光光谱仪、岛津原子吸收分光光度计和测汞仪测定了杭嘉湖平原的嘉兴垃圾焚烧厂周边土壤重金属的含量,利用地统计学方法分析了该区域74个土壤样品中Cr、Mn、Cu、Pb、Fe五种重金属元素浓度的空间分布,并采用单因子指数法和内梅罗综合指数法对该地区土壤进行污染评价。结果表明：该垃圾焚烧厂周边表层土壤上述5种重金属平均含量依次为174.05、707.76、47.68、41.95、39057.89 mg·kg-1。表层富集因子分析表明表层土壤中Cu和Pb的含量受到人为影响。因子分析将5种重金属分成3类,并揭示了3类金属在该区域具有不同的空间分布特征,Cr、Mn、Fe以土壤地球化学作用（37.88%方差贡献）为主导影响因素,Cu、Pb分别以农药施用作用为主（22.06%）、垃圾焚烧源尾气排放（22.74%）为主导影响因素。污染评价结果表明该区域土壤重金属复合污染程度为轻度污染,最大污染贡献来自于Pb（单因子污染指数高达2.16）,厂区周边土壤中重金属存在累积效应,不容忽视。