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1.
The uptake and accumulation of the traffic-related platinum group elements (PGE) Pt, Pd and Rh by the aquatic fauna was investigated. Zebra mussels, eels and barbels were maintained in water containing either road dust or ground catalytic converter material. Following the exposure, samples of fish liver and kidney, as well as the soft tissues of the mussels, were analysed. Our results revealed that all three catalytic noble metals were accumulated by aquatic organisms. The highest bioavailability was found for Pd, followed by Pt and Rh. The concentration factor of Pd forDreissena polymorpha was 5 times higher compared with Pd and only 6 times lower than the essential element Cu. With regard to the increasing emission of Pd the level of this metal has to be monitored very carefully in the environment.  相似文献   

2.
上海市道路灰尘中铂族元素(PGEs)富集特征   总被引:4,自引:0,他引:4  
分析了上海市道路灰尘铂族元素(PGEs)累积水平和分布特征,并探讨了来源变化.样品经王水消解后由ICP-MS测定.研究结果表明,上海市道路灰尘Rh,Pd,Pt浓度分别达到:27.68(61.05-4.50)ng·g~(-1),107.72(12.98-241.4)ng·g~(-1)和34.89(0.36-108.6)ng·g~(-1),分别是参照点的18.33倍、11.12倍和65.83倍,高出地壳丰度值两个数量级以上,与国际其他城市道路灰尘PGEs水平相比,Pt含量较低,Pd和Rh含量处于中间水平;内环-中环区间的道路灰尘PGEs含基最高,从此区域分别往城区内和城区外,PGEs含鼍逐渐降低,至郊区道路,灰尘PGEs含量达到最低,车流量及道路是否限行高污染车辆是主要致因;不同类型道路PGEs浓度水平表现为:快速路(包括环线)>主干道>次干道>高速公路>郊区公路,道路类型会对PGEs分布产生较大的影响,但并没有对其产生决定性作用;PGEs间相关性很好,汽车催化转化器(VECs)排放是道路灰尘PGEs主要来源,Pd含量远高于Pt和Rh,不同于大多数文献的研究结果,VECs类型发生变化是主要原因;同为交通污染排放的元素,Cr与PGEs的相关性很好,Cu与PGEs之间有一定相关性,Zn只与Pt有相关性,而Ph与PGEs没有相关性,Pb和Zn为汽车催化剂毒物是主要原因.  相似文献   

3.
上海市不同类型道路灰尘铂族元素(PGEs)空间分布特征   总被引:1,自引:0,他引:1  
刘玉燕  刘敏  王玉杰 《生态环境》2010,19(10):2414-2418
车辆行驶特征对PGEs排放影响很大,而不同类型道路,其车辆行驶特征会有很大差别。基于此,对上海市5条不同类型的道路进行灰尘PGEs空间分布规律的探讨。灰尘样品用王水消解制样,ICP-MS测定。结果表明:道路灰尘Rh、Pd、Pt的平均含量在主干道为24.50、96.40、29.04 ng·g-1,次干道为23.18、76.92、37.21 ng·g-1,快速路为41.73、188.05、57.21 ng·g-1,郊区高速公路为13.35、63.34、18.01 ng·g-1,郊区公路为7.49、22.76、0.97 ng·g-1,除次干道Pt含量高于主干道外,5种类型道路的PGEs含量均表现为:快速路﹥主干道﹥次干道﹥郊区高速公路﹥郊区公路,郊区高速公路及郊区公路虽然车流量大,但PGEs含量并不高,车流中许多车辆因未安装VECs而不排放PGEs是主要原因。如以1.5-1.6 km道路(两端为路口)为长度单位,主干道、次干道及快速路灰尘PGEs的分布呈波浪型;郊区公路灰尘PGEs的分布呈半圆弧型;郊区高速公路(仅有一端为收费口)灰尘PGEs分布呈先高后低再趋于平稳的折线型,车辆行驶特征的差异是造成不同类型道路灰尘PGEs分布模式差异的主要原因。郊区高速公路及郊区公路的路口(或收费口),PGEs含量往往很高;而主干道、次干道及快速路的路口,PGEs含量不一定很高,频繁的怠速和加减速使得上述三种道路远离路口的地方也常出现怠速是主要原因。  相似文献   

4.
The potential accumulation of platinum group elements (PGE) in the environment from automobile catalysts is high in urban areas, with the major sinks being roadside soils. Therefore, this investigation presented the detailed study on characterized concentrations of Pt and Pd and their enrichment ratios in urban roadside soils in Xuzhou, China in March 2003. Data from 21 roadside topsoil samples analyzed by inductively coupled plasma-mass spectrometer (ICP-MS) illustrated that the medians of concentrations of Pt and Pd were 2.9 and 2.8 ng/g, respectively. Hierarchical clustering analysis indicated that Pt and Pd were mainly from traffic emissions. Compared to unpolluted soils, computation of Pt and Pd enrichment ratios suggested that the Xuzhou roadside soils had average enrichment factors of 3.53 for Pt (in range of 1.22–5.73) and of 3.37 for Pd (in range of 1.35–4.46). Lower Pt/Pd ratios (in range of 0.35–2.86) in relation to similar studies in other countries were observed, which might be due to the different Pt/Pd ratios in Chinese automobile catalytic converters. Moreover, fine fraction (<250 μm) contained higher concentrations of Pt and Pd compared to the coarse fraction (250–500 μmm).  相似文献   

5.
城市地表汞含量及释放通量影响因素分析   总被引:5,自引:1,他引:5  
测定了长春市不同类型地表汞含量及其释放通量,分析了地表汞释放通量的影响因素。研究结果表明,不同地表土样的汞含量存在很大的差异;煤炭堆放地和沥青地地表汞含量较高,应引起足够的重视。地表汞释放通量受地表汞含量、地表类型、降水、太阳辐射等因素的影响。降水期间或降水后期地表汞释放通量明显增加。可见,地表汞释放是一个动态过程,随时间和空间而变化。  相似文献   

6.
The inhibitory and mutagenic action of some Pd(II), Pt(II) and Rh(I) complexes towards various bacterial strains has been evaluated, and some correlations have been found between the chemical behaviour of the complexes and their selective biological activity: most of the complexes cause only a DNA damage repaired by the excision repair system. Particularly, the Rh(I) complexes used in this work show selective antibacterial effects on defective but no effect on wild‐type strains.  相似文献   

7.
In Germany automobile exhaust control by platinum-group element (PGE) loaded catalysts is now well established. By mechanical or chemical attrition, these catalysts could act as a potential source for a significant increase of PGE abundances in the environment. During a recent research program concentrations and distributions of PGE in different soils were measured along the highway A66 Frankfurt-Wiesbaden. 71 nearsurface soil samples were analysed by graphite furnace atomic absorption spectrometry (GFAAS). The results revealed average abundances of 10 ppb platinum and 3 ppb ruthenium. Palladium as well as rhodium were below the analytical detection limit of 2 ppb. With increasing distance from the highway edge PGE values gradually decreased. Only the upmost soil layer, down to 20 cm depth, contains measurable PGE concentrations. Results: There are irregular PGE concentrations of anthropogenic origin in different soils along the highway A66 Frankfurt-Wiesbaden possibly arising from automobile exhaust catalysts. Further monitoring could help to avoid potential environmental hazards. *** DIRECT SUPPORT *** A00HP020 00002  相似文献   

8.
• Pt/CZL exhibits the optimum catalytic performance for HC and NOx elimination. • The strong PM-Ce interaction favors the oxygen mobility and DOSC. • Pd/CZL shows higher catalytic activity for CO conversion due to more Olatt species. • Great oxygen mobility at high temperature broadens the dynamic operation window. • The relationship between DOSC and catalytic performance is revealed. The physicochemical properties of Pt-, Pd- and Rh- loaded (Ce,Zr,La)O2 (shorted for CZL) catalysts before/after aging treatment were systematically characterized by various techniques to illustrate the relationship of the dynamic oxygen storage/release capacity and redox ability with their catalytic performances for HC, NOx and CO conversions. Pt/CZL catalyst exhibits the optimum catalytic performance for HC and NOx elimination, which mainly contribute to its excellent redox ability and dynamic oxygen storage/release capacity (DOSC) at lower temperature due to the stronger PM (precious metals)-support interaction. However, the worse stability of Pt-O-Ce species and volatile Pt oxides easily result in the dramatical decline in catalytic activity after aging. Pd/CZL shows higher catalytic activity for CO conversion by reason of more Olatt species as the active oxygen for CO oxidation reaction. Rh/CZL catalyst displays the widest dynamic operation window for NOx elimination as a result of greater oxygen mobility at high temperature, and the ability to retain more Rh-O-Ce species after calcined at 1100°C effectively restrains sintering of active RhOx species, improving the thermal stability of Rh/CZL catalyst.  相似文献   

9.

This study presents the level of platinum in urban environment in and around Seoul, the capital city of Korea. Road dust, roadside soil, and tree bark samples were collected from the sites of various traffic volumes and from control sites in the suburbs. The above samples were analyzed for Pt by ICP-MS and other heavy metals by ICP-OES. Platinum levels in road dusts and roadside soils from Seoul were in the range of 3.8–444 ng/g (av. 115.0 ng/g) and 0.7–221 ng/g (av. 49.7 ng/g), respectively, whereas those in the suburbs were in the range of 2.3–5.2 ng/g (av. 3.9 ng/g) in road dusts and 0.4–5.1 ng/g (av. 2.4 ng/g) in roadside soils. The highest Pt levels in road dusts were found from major roads with high traffic volume. The remarkable difference in average Pt level between heavy traffic roads (av. 132.2 ng/g) and light traffic roads (av. 22.8 ng/g) reflects that an important source of Pt in roadside environment is automobile catalytic converter. High Pt level in road dust was found from the site of erratic stop–start driving condition, for example, 178 ng/g Pt in road dust around a vehicle crossing gate. Platinum level in tree barks ranged from 0.9 to 4.5 ng/g, which indicates the existence of Pt-containing particulate matter in the atmosphere. Road dusts with high Pt level were enriched in traffic-related heavy metals.

  相似文献   

10.
This study presents the level of platinum in urban environment in and around Seoul, the capital city of Korea. Road dust, roadside soil, and tree bark samples were collected from the sites of various traffic volumes and from control sites in the suburbs. The above samples were analyzed for Pt by ICP-MS and other heavy metals by ICP-OES. Platinum levels in road dusts and roadside soils from Seoul were in the range of 3.8–444 ng/g (av. 115.0 ng/g) and 0.7–221 ng/g (av. 49.7 ng/g), respectively, whereas those in the suburbs were in the range of 2.3–5.2 ng/g (av. 3.9 ng/g) in road dusts and 0.4–5.1 ng/g (av. 2.4 ng/g) in roadside soils. The highest Pt levels in road dusts were found from major roads with high traffic volume. The remarkable difference in average Pt level between heavy traffic roads (av. 132.2 ng/g) and light traffic roads (av. 22.8 ng/g) reflects that an important source of Pt in roadside environment is automobile catalytic converter. High Pt level in road dust was found from the site of erratic stop–start driving condition, for example, 178 ng/g Pt in road dust around a vehicle crossing gate. Platinum level in tree barks ranged from 0.9 to 4.5 ng/g, which indicates the existence of Pt-containing particulate matter in the atmosphere. Road dusts with high Pt level were enriched in traffic-related heavy metals.  相似文献   

11.
Traffic related platinum deposits on, or near to, the roads. Platinum accumulation was studied using the method of standardised culture of grass (Lolium multiflorum) at locations with different traffic exposure in the region of Munich. Grass cultures from 6 locations with high traffic exposure, and 3 reference locations far away from traffic emissions, were analysed in 1992 and 1993. The results show a good indication of the platinum emissions byLolium multiflorum. The platinum concentrations rose with the increasing traffic. They diminished with growing distance from the verge of the road. The highest average platinum concentrations were measured at locations close to highly frequented urban roads, in the range 0.8 to 2.9 μg/kg dm. The average platinum concentration at locations far from emissions was found in the range of 0.17 to 0.51 μg/kg dm in 1992 and 1993. The good correlation between the platinum concentrations in grass cultures and the concentrations of other traffic-related elements, like antimony, chromium and lead, verifies the dependence of platinum accumulation from traffic.  相似文献   

12.
钟铱钧  刘泽菊 《环境化学》1997,16(3):204-207
本文考虑了乙腈、硝基甲烷和乙二胺在Pt/HM,Pd/HM和CuO/HM催化剂上氧化降解产物随反应温度的变化。在实验温度范围内,含氮产物在N2,N2O和NO2。随着反应温度的升高,硝基甲烷氧化降解的N2选择性呈单调下降;而乙腈和乙二胺的N2选择性出现极小值;高温时N2选择性升高可能是氧化生成的NO在高温时更在利于和CN基或NH2基相互反应生成N2的缘故。对于乙腈和乙二胺的催化氧化降解活性为:Pt/H  相似文献   

13.
Above-ground biomass biomass of Molinia caerulea from 36 sites throughout Britain was analysed for concentrations of elements (N, P, K, Ca, Mg, Fe, Mn, Cu, Zn and Na), with matching analyses of soil nutrients, together with pH and LOI. Between-year and seasonal variation in the nutrients was also studied at one of the sites. the grass was found on acid sites ranging between pH 3.1 and 5.8. the soil humus content varied widely, and there were significant correlations between that and elements (N, P, K, Ca, Mg and Na) in the soil. Concentrations of calcium, magnesium, zinc and manganese in the plant material were significantly correlated with extractable levels in the soils. Between year variation in the plant nutrient concentrations at one site was of a similar order to variation between the sites. Generally there was less variation in nitrogen, phosphorus and potassium tissue levels than in calcium, magnesium, zinc and copper. Iron and sodium were the most variable. Tissue concentrations of nitrogen, phosphorus, potassium and copper declined throughout the growing season, whereas magnesium, calcium and iron built up until August/September after which a decline set in as the leaves senesced. the results are discussed in relation to the importance of standardizing the time of sampling, in comparison with concentrations of tissue levels in other plants and the growth strategy of this deciduous grass.  相似文献   

14.
Vinylbenzyl chloride/divinylbenzene gel copolymer beads have been modified using piperidine, hexamethyleneimine, piperazine, 1-(2-aminoethyl)piperazine, and N-cyclohexyl-1,3-propanediamine. These resins were then tested for the sorption of noble metal ions, namely, Re(VII), Pd(II), Pt(IV), and Au(III), from a 0.1 M HCl solution. The effect of these resins on the sorption of other coexisting ions, such as Cu, Ni and Fe, was also studied. Of the resins tested, resin 4 [1-(2-aminoethyl)piperazine groups] showed the highest sorption capacity for Pt(IV) and Re(VII) from single and multicomponent solutions, with the sorption of Pt(IV) from the multicomponent solution (Re, Au, Pd, Pt, Cu, Ni Fe) in 0.1 M HCl reaching 68 mg Pt/g.  相似文献   

15.
This study presents the level of platinum in urban environment in and around Seoul, the capital city of Korea. Road dust, roadside soil, and tree bark samples were collected from the sites of various traffic volumes and from control sites in the suburbs. The above samples were analyzed for Pt by ICP-MS and other heavy metals by ICP-OES. Platinum levels in road dusts and roadside soils from Seoul were in the range of 3.8-444 ng/g (av. 115.0 ng/g) and 0.7-221 ng/g (av. 49.7 ng/g), respectively, whereas those in the suburbs were in the range of 2.3-5.2 ng/g (av. 3.9 ng/g) in road dusts and 0.4-5.1 ng/g (av. 2.4 ng/g) in roadside soils. The highest Pt levels in road dusts were found from major roads with high traffic volume. The remarkable difference in average Pt level between heavy traffic roads (av. 132.2 ng/g) and light traffic roads (av. 22.8 ng/g) reflects that an important source of Pt in roadside environment is automobile catalytic converter. High Pt level in road dust was found from the site of erratic stop-start driving condition, for example, 178 ng/g Pt in road dust around a vehicle crossing gate. Platinum level in tree barks ranged from 0.9 to 4.5 ng/g, which indicates the existence of Pt-containing particulate matter in the atmosphere. Road dusts with high Pt level were enriched in traffic-related heavy metals.  相似文献   

16.
化学农药污染土壤植物修复中的环境化学问题   总被引:7,自引:1,他引:7  
报道了利用植草修复受DDT,BHC和Dicofol污染的研究,讨论了化学农药污染土壤植物修复中,农药在植物中富集与在土壤中降解以及结合残留等环境化学问题。研究表明,在植物修复的过程中,通过草对农药吸收的途径而去除土壤中污染物的作用所作的贡献很小,植草的作用可能是通过草的根部向土壤释放酶和某些分泌物,从而激发土壤中微生物的活性,并加速农药生物降解作用的结果。草在不同土壤中修复能力的差异,可能与不同土壤中所存土著微生物的差异以及其活性受酶和某些分泌物所激发差异的结果。选择能使根际区产生强烈的生物降解作用的草品种,是利用草作为化学农药污染土壤修复的关键。土壤与植株中农药结合残留的形成可能是土壤中污染物消除的又一个重要因素。  相似文献   

17.
In order to study the relation of the mobility and distribution of metals between Tamarix parts and their crystal salts – soil system, different experiments were conducted with plant-rich and plant-free soils at the banks of river Nile, Aswan, Egypt. For these purposes, Tamarix top and subsoil samples near and far from the plant were collected from six different locations at the banks of river Nile. Elemental analysis of Fe, Mn, Ca, Mg, Cr, Cu, Ni, Zn, Cd and Pb in soil, and in different parts of Tamarix and their crystal salt samples was carried out by atomic absorption spectrometry, whereas Na and K were measured by atomic emission spectrophotometry. The bioavailability of metals in the soil samples was evaluated by determining their contents using sequential extraction single-step, providing higher metal concentrations in occluded Fe/Mn oxide fraction. The ratio of heavy metal concentrations in topsoil to that in subsoil enhancement (RTE) ranged from 0.67 to 4.4 and 0.22 to 4.61 for soil Tamarix and soil free from plant, respectively for all measured total element concentrations. Data indicate that the mobility expressed as transfer factor (TF) was obtained as Fe?>?Mg?>?Cr?>?Mn?>?Ca?>?K?>?Na, for Tamarix leaves. The major part of accumulated Na in Tamarix is retained in the plant leaves, while roots accumulated high concentration of Co.  相似文献   

18.
Concentrations of platinum and lead were measured in common grass sampled near the Autobahn. Additionally, platinum was determined in spot checks of ash from seawage sludge incinerators to 1972. The increase in Pt levels since 1987 was traced back to releases from automobile catalytic converters. The emission rate of a car equipped with a catalytic converter has been estimated by comparison with Pb.  相似文献   

19.
Soil samples were taken from residential gardens, grasslands and forests at 22 locations in Marsberg, North Rhine-Westphalia, and analyzed for PCDD/F. Sampling was concentrated on the vicinity of a former copper smelter where copper waste material (calledKieselrot) was deposited and emissions from former stacks contaminated a large land area. Maximum PCDD/F-concentrations were 407 ng TE GBA/kg dm in garden soil (0–30 cm depth), 98 ng TE BGA/kg dm in agricultural grassland (0–10 cm depth), 227 ng TE BGA/kg dm in wasteland, and up to 8073 ng TE BGA/kg dm in forest soils. PCDD/F-levels in soil decreased with increasing distance from the former sources providing a large historic emission problem, apart from the still existing kieselrot waste site. Ash residues from former flue gas duct showed up to 2,4 mg TE BGA/kg dm. PCDD/F-concentrations in vegetable samples from highly contaminated garden soils and grass from agricultural grassland were found to be relatively low in relation to soil values. PCDD/F-levels in salad showed a mean of 2,2 ng TE BGA/kg dm while grass concentrations were <6 ng TE BGA/kg dm. Thus, no correlation was found between soil and vegetation values with the exception for carrot roots where obviously a small transfer of PCDD/F between the two media took place. PCDD/F-content in grass taken over the vegetation period showed a tendency to increase toward the end of the growing season, which is probably related to changes in the dry matter yield over the season. No correlation was found in general between soil, grass and milk PCDD/F contents when all samples were taken from the same grassland. PCDD/F-concentrations in milk ranged between 0,6 and 1,1 pg TE BGA/g milkfat and were thus in the same range as consumer milk in the Federal Republic of Germany. PCDD/F in needles from conifers showed a clear relationship with respect to distance from the former waste site. The relatively high levels in conifer needles [36 ng TE BGA/kg dm] were obviously due to sporting activities (i.e. motocross racing where contaminated material was resuspended and deposited on surrounding trees).  相似文献   

20.
Topsoils from Poland were analysed for total and extractable zinc, and for a range of major elements and selected soil properties. Plant samples from the same locations were also analysed for zinc content. The geometric mean concentrations of zinc in samples were (mg/kg dry weight): soil total-Zn, 45.9; soil extractable-Zn 3.1; grass, 30.0; dandelion-tops, 45.9; dandelion-roots, 23.2; oat-leaves, 20.0; oat-grains, 29.7; lichens, 111.5. Significant relationships were found for zinc in grass and extractable-Zn in soils as well as for zinc in lichens and both total and extractable Zn in soils. Zinc in soils varied for soil kinds and regions.  相似文献   

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