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 31 毫秒
1.
The peat of the Negril Morass in Western Jamaica was sampled at depths down to 7 m in directions parallel and perpendicular to the seashore, and the samples were analysed for Al, As, B, Br, Ca, Ce, Cl, Co, Cr, Cs, Dy, Eu, Fe, Hf, I, La, Mg, Mn, Na, Sb, Sc, Sm, Sr, Ti, U and V by instrumental neutron activation analysis and by spectrophotometry. The peat is high in ash content, but the concentrations of most elements are below crustal abundances and therefore provide no evidence of nearby mineralisation. The elemental concentrations indicate that no particular environmental hazards are to expected from the use of this peat in electricity generation.  相似文献   

2.
Study of the chemical composition of shell of exoskeletonous organisms in the past has required the sacrifice of the organism. Because the beam of the proton microprobe is relatively nondestructive and analyzes the surface layer of the shell, organisms do not have to be killed. The present paper presents results of a preliminary experiment in which distribution of elements (Na to Sr) in shell of living juvenile oysters, Crassostrea virginica (Gmelin), was studied in situ with a proton microprobe at monthly intervals for four months. The relative concentration of 16 elements was measured in the newly deposited prismatic edge of the right valve of three oysters reared in controlled laboratory conditions. Na, Mg, Al, Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, Br, and Sr were detected in concentrations as low as a few parts per million relative to the concentration of standards added to pure CaCO3. Concentration of elements varied nominally among shells of the three individual oysters and in their successive ontogenetic stages. Fluctuations in concentration of Na, Mg, S, Cl, Ca, Mn, Fe, Cu, and Zn were generally similar in the two normally growing oysters, but differed from those in the oyster that stopped growing. Trends in concentration of Al, Si, and Sr were similar in the three oysters: those of Br were variable. Relative concentrations of Na, Cl, S, Mn, Fe, and Zn increased slightly with age of oysters, that of the other elements stayed relatively constant. Concentration of most elements was higher in shell than in seawater. Variable concentrations, especially of Na, Cl, and Si in valve edges, tend to support the hypothesis of earlier workers that separate mineral phases are present as impurities entrapped within the shell during calcification.  相似文献   

3.
Size segregated suspended particulate matter (PM2.5 and PM10-2.5) in air at four major petroleum-filling stations in Ile-Ife, Nigeria, were monitored using double staged “Gent” stacked samplers to assess variations in mass loads and elemental concentrations of 25 elements. Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, Zr, Cs, Ta, W, and Pb were determined in both fractions by external ion beam proton-induced X-ray emission technique. Enrichment factors and pollution indices were calculated and results revealed that most elements were anthropogenic in both fractions with concentrations exceeding the World Health Organization guideline standards.  相似文献   

4.
利用土壤元素数据2069448个,鼻咽癌死亡调查资料22560例,研究了鼻咽癌死亡率与土壤环境中61个元素质量分数的相关性。结果表明,汞、铅、硒、针、锡、钛、钽、溴、碘元素质量分数与鼻咽癌死亡率呈非常显著的正相关;铪元素质量分数与鼻咽癌死亡率呈显著的正相关;铟、镱、镥、铀、锆、铋、碲元素质量分数与鼻咽癌死亡率呈较显著的正相关。锰、钠、镁、钙、锶元素质量分数与鼻咽癌死亡率呈非常显著的负相关;钾、钡元素质量分数与鼻咽癌死亡率呈较显著的负相关。钒、铷、铯、银、铝、镓、铊、钪、钇、镧、铈、钕、钆、镝、钬、铒、铥、钼、钨、铁、砷、镉、钴、铬、铜、氟、镍、锌、锂、铍、硼、镨、钐、铕、铽、锗、锑元素质量分数与鼻咽癌死亡率无明显的相关性。  相似文献   

5.
The analytical results of 53 manure samples determined by wet digestion and dry ashing procedures were compared in order to evaluate their relative suitability for recovering different nutrient elements in manure and manure compost. Wet digestion recovered greater amounts of phosphorus (P), potassium (K), calcium (Ca), manganese (Mn), and zinc (Zn) in more samples than dry ashing. Nutrient contents in the samples were highly variable, with coefficients of variation (CV) ranging from 38% for magnesium (Mg) to 161% for copper (Cu) analyzed by the wet digestion procedure, and from 47% to 138% for Mg and Cu analyzed by the dry ashing procedure. The mean values of P, K, Ca, Mn, and Zn averaged for the 53 samples were significantly higher using wet digestion than dry ashing procedure, but both procedures recovered comparable amounts of iorn (Fe), Mg, and Cu. Correlations analysis between both procedures for each element showed reasonable to fair agreements for Ca (R 2?=?0.93), K (R 2?=?0.93), P (R 2?=?0.90), Mg (R 2?=?0.84), Fe (R 2?=?0.87), Mn (R 2?=?0.73), and Cu (R 2?=?0.66), but poor agreement for Zn (R 2?=?0.44). The low agreement between procedures for Zn suggests that wet digestion, which gave a higher recovery, should be a preferred procedure for analyzing Zn in manures.  相似文献   

6.
Various elements and inorganic ions in rice straw and ash samples were analyzed by using inductively coupled plasma atomic emission spectrometry (ICP‐AES) and ion chromatography (IC). Five major elements: Mg, Mn, Al, Ca, and Fe and eight minor and trace elements: Cr, Cu, Ti, Zn, La, Sr, Ba, and Hg were detected in these samples, at more than ppm‐level. In ash samples the trace elements such as Y, As, V, Se, and Sc were also identified. The concentrations of SO4, PO4, Cl, Na, and K ions in these samples were higher than those of other ions measured. These elements and inorganic ion concentrations were approximately one order of magnitude higher in the ash than in the straw samples. Gas chromatography/mass spectrometry (GC/MS) and library search showed the presence of fatty‐, carboxylic‐ and nicotinic acids, and their derivatives in small quantities in the straw samples.  相似文献   

7.
采用ICP法测定了不同地区何首乌植物及其生境土壤中的15种元素(Al、B、Ba、Ca、Cu、Fe、K、Mg、Mn、Na、Ni、P、Sr、Ti、Zn),分析比较了各种元素在不同地区何首乌体内和生境土壤中的分布规律及不同地区何首乌对无机元素的吸收富集能力.结果表明,不同地区何首乌和土壤中无机元素含量存在着显著差异,德庆、井冈山、靖西三地何首乌的Mn含量较高;不同地区何首乌对元素的富集系数无显著性差异,而何首乌对不同无机元素的富集系数则有显著差异,主要表现在对Ca、K、Mg、Sr的吸收富集能力较强.表6参14  相似文献   

8.
We report the results of a study with proton-induced X-ray emissions (PIXE) of the distribution and concentration of 15 chemical elements (Na to Sr in periodic chart) in four microstructural and two mineralogical regions of shell of rapidly growing adult oysters [Crassostrea virginica (Gmelin)]. Hatchery-raised oysters were grown in Broadkill Estuary, Delaware, USA, for 16 wk in summer 1978. Their valve edges were filed as a marker, and the oysters were replaced in the estuary, where they grew rapidly. Shell deposited after marking had a normal microstructure and mineralogy after a narrow zone of disturbance. After 17 d oysters were sacrificed, and different mineralogical and microstructural regions of valves of three oysters, and parts of valves of two oysters, were analyzed for the elements Na to Sr. Quadrats (2.5 × 0.45 mm) included three calcitic groups (prismatic, foliated, chalky) and one aragonitic (myostracal) microstructural group; four quadrats were on the exterior and five on the interior of right and left valves. Inhalant and exhalant margins of valves and ground right and left valves of one oyster were also analyzed. Elemental chemistry of different regions of shell varied among the three microstructural groups within the single calcitic polymorph, between aragonitic and calcitic regions, and between exhalant and inhalant margins of the valves. Elements were most concentrated in the prismatic region of the right valve. Element concentrations were similar in ground right and left valves, except for higher levels of Si, Fe, and Zn in the right valve (corresponding to their high contents in prismatic shell) and of Cl in the left valve (reflecting high concentration in chalky shell, abundant in this valve). Na, Mg, Cl, Cr, Cu, Zn and Br were more concentrated in prismatic than in foliated shell. Chalky shell contained higher concentrations of Na than did prismatic shell, and high concentrations (but lower than in prismatic shell) of Mg, Cl, Ti, Mn, Fe, Zn and Br. Element concentration in myostracum was approximately the same as, or lower than, in foliated shell, except for Sr, which was higher than that in any other shell group. In the right valve most elements were concentrated in inhalant margins, and on the left valve, in exhalant margins. With increased weathering of the exterior surface of prismatic shell, Mg, Si, and Mn increased in concentration and Na, Al, Cl, Ti, Cr, Fe, Br, and Sr decreased.  相似文献   

9.
不同栽培基质对石山珍稀濒危植物苗期生长的影响   总被引:6,自引:0,他引:6  
对 6种石山珍稀濒危植物在石灰岩土壤和酸性红壤上的苗期生长状况及体内化学元素含量进行了对比研究 ,结果表明 :(1 )每种植物在 2种土壤上的物候学特征基本一致 ;(2 )小花异裂菊和青檀在石灰岩土壤上生长量比酸性土壤上高 ,海南椴在酸性土壤上生长量比石灰岩土壤上高 ;(3 ) 6种植物体内Ca、B 2种化学元素的含量是石灰岩土上比酸性土上高 ;除小花异裂菊外 ,Al在其它 5种植物中的含量都是酸性土上高于石灰岩土上 ,小花异裂菊则是石灰岩土上高于酸性土上 ;(4 )K、Zn、B的生物吸收系数是石灰岩土高于酸性土 ,而N、P、Ca、Mg、Fe、Al、Mn则是酸性土高于石灰岩土。  相似文献   

10.
11.
采用单道扫描等离子体发射光谱仪(ICP)和微波消解仪测定了新疆沙冬青和蒙古沙冬青两种珍稀植物的叶片及生境土壤环境中15种无机元素(Al、B、Ca、Cu、Fe、Mg、Mn、Na、Ba、La、Co、Ni、Pb、Rb和Ti)的含量,其中两种沙冬青叶片及生境土壤中含量最大的元素均为Ca,最小的均为Co.应用两个独立样本检验(Independent-samples T Test)中的曼-惠特尼U检验法(Mann-Whitney U)分析15种无机元素的差异性,结果显示,两种沙冬青的土壤环境相似;叶片的无机元素除了5种元素(B、Fe、Co、Ni和Ti)呈现显著性差异以外,其余元素含量差异不显著;通过比较叶片和土壤的元素含量发现,15种元素均呈现显著性差异;通过叶片内无机元素的浓度与生境土壤中该元素浓度的比值比较,发现Pb和Ti两种元素的叶片内浓度与生境土壤中浓度比值存在显著差异.图1表7参25  相似文献   

12.
用核子微探针进行单个大气颗粒物的分析   总被引:7,自引:1,他引:7  
沙因  谷英梅 《环境化学》1995,14(6):518-523
本文对单个大气颗粒物进行了分析研究,用核子微探针对首钢地区单个大气颗粒物进行了扫描分析,用三维等高线法给出了各种元素在一群单个大气颗粒物中的二维分布。从一群单个大气颗粒物中各元素的二维分布可对首钢地区大气污染的特征及来源进行分析研究。  相似文献   

13.
大气气溶胶中元素种态研究   总被引:18,自引:0,他引:18  
应用化学逐级提取流程对国际原子能机构(简称IAEA)气溶胶、室内和室外气溶胶、煤飞灰中元素的组成和种态进行了分析,应用仪器中子活化法测定了各种态中元素的含量,计算出元素在各种态中的分配比例。按照气溶胶中元素不同种态的环境和生物活性以及主要来源来分类,评述了元素在环境和生态系统中的吸收和转化能力,并对气溶胶中元素对环境的影响作出了初步的探讨。实验数据表明,气溶胶中的不同元素在各种态中的分布是有差异的。地壳来源元素中,Sc,Al,Fe和Ti主要分布在不溶物态中,稀土元素主要分布在氧化物态和不溶物态;不溶物态沉降到地表后不易进行迁移和转化,对环境的影响较小;氧化物态性质比较活泼,可以在大气中发生化学反应。Mn在气溶胶中主要分布在水可溶态和氧化物态,环境可交换性要比Al,Fe,Ti等大得多。人为来源元素的环境可交换态的比例都比较高,这说明它们通过干、湿清除过程沉降到地表后,水可溶态可以直接进入水循环;碳酸盐、氧化物和有机物态可以在适当的条件下与环境中的其他物质发生化学反应,生成易溶于水的化合物进入生态环境中,对环境影响较大。  相似文献   

14.
The concentration levels of major (Al, Ca, Fe, K, Mg, Mn, Na, Si, Ti) and some trace (Be, Se, Tl) elements were determined by atomic absorption spectrometry for the coal fly ashes emitted in the combustion of anthracite and soft coals. Total contents and concentration profiles were established for all elements studied as a function of the mean particle size. The content of those elements volatilized during coal combustion (Se, Tl) decreases with increasing particle size, while the unvolatilized elements show small changes in their concentration profiles. The content of aluminium shows a minimum level at a mean particle size of about 25 μm.  相似文献   

15.
池塘养殖及野外移殖三角帆蚌元素积累的差异   总被引:1,自引:0,他引:1  
以从湖北公安养殖池塘移殖到三峡库区童庄河自然水域试养1 a和仍在原池塘养殖的同1批次三角帆蚌(Hyriopsis cumingii)为对象,用电感耦合等离子质谱仪测定了2地三角帆蚌软组织中K、Mg、Ca、Fe、Zn、Mn、Cu、As、Al、Cr、Ni、Se、Mo、Ag、Cd、Ti、Pb 17种元素的含量.结果表明,虽然2水域中三角帆蚌软组织内各元素含量间的高低差异具有相似的趋势,体现了三角帆蚌对元素积累的特征,但自然水域蚌中有9种元素的水平高于养殖水域,提示不同栖息环境背景对元素的积累水平能产生重要影响.自然水域单个三角帆蚌体内软组织中元素积累的平均负荷量普遍高于养殖池塘的个体,提示三角帆蚌具有显著的元素吸收、净化能力.本研究为今后通过大规模移殖双壳贝类来监测自然水域元素污染提供了依据.  相似文献   

16.
Reconnaissance soil geochemical survey of Gibraltar   总被引:2,自引:0,他引:2  
The extreme density of population of Gibraltar, situated at the southern tip of Spain, exerts considerable pressure on land use and thus future planning is of utmost importance. An initial reconnaissance soil geochemical survey of Gibraltar was based on 120 surface samples (0–15 cm) taken from a wide range of exposed, either bare soil or vegetated sites, to provide the optimum geographical distribution. The total elemental concentrations of 26 elements (Li, Na, K, Be, Mg, Ca, Sr, Ba, Al, La, Ti, V, Cr, Mo, Mn, Fe, Co, Ni, Cu, Ag, Zn, Cd, Pb, P, S, As) were determined by nitric/percholric acid digestion followed by inductively coupled plasma-atomic emission spectrometry (ICP-AES) analysis. The reconnaissance data shows that the spatial distribution of various elements depended on previous and present land use. Most elements (Ca, Cr, Mg and Mn excluded) exhibited relatively high concentrations in civilian and natural soils. Trends have been established for many elements, and concentrations exceeding guideline values have been found in certain areas of Gibraltar. This reconnaissance of Gibraltar is at present being followed by a more detailed baseline geochemical survey, which will establish the extent and magnitude of the variations in major and trace elements in soils and dusts, assess the impact of industrial, commercial and urban development on the geochemical landscape and to make recommendations concerning sustainable development.  相似文献   

17.
Scanning electron microscopy with energy-dispersive spectroscopy has been used for both morphological and elemental chemistry analyses of atmospheric particles. This technique allows the in situ observation of individual aerosol particles in the sample chamber. Aerotransported particles were analysed from seven monitoring stations located in the Metropolitan Zone of Toluca Valley (MZTV). Several different morphologies were identified: aggregates, porous spheres, rough and smooth compact material. The elemental composition included C, Na, Mg, Al, Si, S, Cl, K, Mn, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn and Ce. These are semiquantitative analyses considering the bulk sample or individual particles. It was possible to correlate or confirm some chemical associations such as C–S, Ca–S–O and Si–Al–O, probably due to the presence of compounds derived from incomplete combustion, building tailing materials and aluminosilicates of cortical origin. Bioaerosols such as pollen, spores, brochosomes and diatoms were identified in the zone; all these types of particles have a natural origin too. Several types of suspended particles were identified in the MZTV, they were from different sources (natural and anthropogenic) to which the population can be potentially exposed, and may cause harm in the short- and long-term, according to their chemical element composition and size.  相似文献   

18.
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   

19.
Eleven metals (Ca, Mg, Fe, Zn, Cu, Mn, Cd, Co, Cr, Ni and Pb) were estimated in hair samples of metal arc welders and a control group with the same socioeconomic background. Nitric acid–perchloric acid wet digestion procedure was adopted for the estimation of endogenous metal contents by ICP-AE technique. The study exhibited the following increasing order of the metal concentrations: Cd??1, dry weight, respectively. On average, the levels of Mn, Ni, Pb and Fe were found to be 1.5–2.4 times higher in the hair of welders compared with controls. Besides age and exposure which were strongly correlated, Cu–Mg, Mn–Mg, Ca–Co and Cd–Zn also showed significantly positive correlations. The identification of metal sources, done by cluster and principal component analyses, revealed four factors: age and exposure; Cu, Mg, Mn and Fe; Ca and Co; Cd, Zn, Ni and Pb. High levels of Fe were found to have a depleting impact on Co levels. The arc welders were feared to accumulate heavy metals in their bodies due to long-term endogenous exposure.  相似文献   

20.
Investigations of the dandelion, Taraxacum officinale Web. in Poland, Romania and Germany showed that the species concentrates various elements dependent on the intensity of the pollutants. In this study, we followed up the question of whether T. officinale enriches pollutants by the atmospheric deposition on the leaves or via the soil. Therefore, samples from at least 10 plants and a soil sample at 57 sample sites were collected from a grid of 500 m × 500 m. In addition to the analysis of the total soil sample, the (mobile) ion pool of the soil (DIN V 19739) was analysed. The elements Al, As, Ba, Ca, Cd, Ce, Co, Cr, Cu, Fe, Ga, K, Mg, Mn, Mo, Na, Ni, Rb, Sr, Ti, Tl, V, and Zn were determined through the use of spectrometry with inductive coupled plasma (ICP-MS and ICP-OES). The results are compared with the element concentrations of washed and unwashed leaf samples in T. officinale. We could only find two direct correlations (Ti and Zn) between the element content, of the entire soil samples, but 14 correlations (As, Ba, Cd, Cu, Ga, K, Mn, Mo, Na, Ni, Rb, Ti, Tl und Zn) between the ion pool of the soil and the washed samples. The grid point data interpolation by ArcInfo showed a similar distribution pattern for the unwashed leaf elements Al, Ce, Fe, Ti and V (r≥0.75). The elements Al, Ce, Fe, Ti, and V are washed out at the same ratio. Thus, although the concentration of these elements were significantly reduced by the washing procedure, the correlations were not influenced. The admissibility of the grid point data interpolation for a distribution map of the town area was investigated, as well. It is shown that the element content varies with the land use (meadow, field, rural areas), the sampling point and the local pollutants. However, none of the discussed elements, Al, Ce, Fe, Ti, and V, is significantly influenced by the land use. The data allows one to make the conclusion that the elements of Al, Ce, Fe, Ti and V are dependent on the dry and wet deposition on the leaves of T. officinale. These elements are taken up not only by the roots, but also by the surface of the leaves. This is evident because there is no correlation between one of these elements in the leaves and the ion pool of the soil.  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