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1.
Twenty-eight pairs of coarse and fine air particulate samples were collected in front of an automotive workshop located at Tasmasipabad on Chaklala Road in Rawalpindi using a Gent sampler and polycarbonate filters. These samples were collected during the period; 7th to 27th of April 2009. The gravimetric data (PM2.5 and PM10) were obtained for these samples and were found to exceed the Pakistani standards. Black carbon (BC) was also determined using reflectance measurements and it was found that BC contributed significantly more to the fine mass than to the coarse fraction; i.e. ~10 to ~3 %, respectively. This is not surprising as soot is emitted by combustion processes and is usually found in the fine particulate mass. Using instrumental neutron activation analysis technique all 28 pairs of filters were analyzed for >30 elements. Major elements, in the coarse mass fraction, include Al, K, Fe, Sr, Na, and Zn implying soil as the major source while BC was found to be a higher contributor of PM2.5. An episode of high PM2.5 was observed on the 18th of April 2009. Back trajectory analysis showed that the air mass originated from the Middle East where a dust storm was in progress over Iraq.  相似文献   

2.
Air particulate matter (PM) was collected in two size fractions using stacked filter units (SFUs) provided by the International Atomic Energy Agency (IAEA) from the industrial area of Islamabad. Nucleopore polycarbonate filters were used for collecting from Oct 98 to Jun 99 the particulate matter in coarse and fine size fractions. The samples were characterized by the instrumental neutron activation analysis (INAA). About 33 elements were quantified using different irradiation and counting protocols.  相似文献   

3.
Summary This study provides useful information about the level and chemical composition of particulate matter and about the possible sources of the aerosol pollutant in Islamabad, the capital of Pakistan. Atmospheric aerosol samples were collected during winter (January and February) 1995, from two locations of Islamabad, namely of Sector F-7 and Sector I-9. Twenty-four elements were detected by using thermal neutron activation analysis (NAA) and atomic absorption spectrometry (AAS). The concentration of total suspended particulates (TSP) in the area around the industrial sector (I-9) was found to be more than twice higher (297 μg/m3) than in the Sector F-7 (133 μg/m3). The enrichment factor analysis revealed Zn, As, Br, Sb, I and Pb, originated mainly from anthropogenic sources. The elemental ratio analysis indicated that both Sectors I-9 and F-7 are under the influence of coal burning processes whereas transportation is responsible for the toxic pollutants Pb and Br. The present results were discussed and compared with those of the literature. The results may also serve as base line level as this work employed samples collected in 1995 and many of the air environmental change factors occurred after the sampling year.  相似文献   

4.
One Plus Sequential Air Sampler??Partisol was placed in a small village (Foros de Arr?o) in central Portugal to collect PM10 (particles with an aerodynamic diameter below 10???m), during the winter period for 3?months (December 2009?CMarch 2010). Particles masses were gravimetrically determined and the filters were analyzed by instrumental neutron activation analysis to assess their chemical composition. The water-soluble ion compositions of the collected particles were determined by Ion-exchange Chromatography. Principal component analysis was applied to the data set of chemical elements and soluble ions to assess the main sources of the air pollutants. The use of both analytical techniques provided information about elemental solubility, such as for potassium, which was important to differentiate sources.  相似文献   

5.
Ambient aerosol particles smaller than 2.5 µm (PM2.5) are getting more and more attention worldwide. While legal focus is mainly on sample mass, the composition of the particles is an important research field gaining increased interest. The interest is not only connected to possible health effects of the elemental content of the particles, but the elemental determination can also add valuable information for source apportionment. Samples were collected during 20 days in November 2007 at the campus of the Chemistry Department, University of Gothenburg, Gothenburg, Sweden. The particles were collected using a cyclone that separates the PM2.5 particles from the air stream and impacts them on polycarbonate filters. Filters were changed at early afternoon. The samples were analyzed for particulate mass, black carbon (BC) and the elements S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, As, Br, Cd and Pb. Several of the elements were above detection limit in only a few of the samples. Total reflection X-ray fluorescence (TXRF) spectrometer based on the Wobi TXRF module supplied by the International Atom Energy Agency (IAEA) has been used for the determination of most trace elements in the samples. A Graphite Furnace Atomic Absorption Spectrometer (GF-AAS) was used for complementary trace element analysis and a reflectometer was used to analyze black carbon. Before elemental analysis the filters were digested using a microwave digestion system with temperature and pressure control. The results showed a large variation in sample mass, BC and analyzed elemental concentrations. The variation of the different constituents did not show the same pattern. This added to the picture of different sources for different pollutants. The highest S concentration was noted on a day when the air masses were determined to come from the southeast, i.e. Poland and some other Eastern European countries. From the results it can be concluded that more work is needed on the TXRF spectrometer to optimize it for determination of the EU legally regulated elements As, Ni, Pb and Cd. Despite this the study shows that there is no problem in meeting the AAQS limits for Cd and Pb in Gothenburg.  相似文献   

6.
An approach for producing simulated air particulate matter (APM) deposited on filters has been developed and investigated as to its usefulness for yielding large batches of filters as a future reference material. The APM deposited on the filters was a material collected from an urban industrial area, and had been milled to approximate a material of PM-2.5 particle size distribution. The milled APM material was loaded onto filter substrates (Nuclepore) through the deposition of aliquots from a liquid suspension via vacuum filtration. It should be noted that these filters do not represent a typical PM-2.5 elemental composition, since the milling increased the proportion of crustal materials and the suspension in liquid decreased the sulfate content. Homogeneity between filters was tested using INAA (whole filter analysis) and ED-XRF and PIXE and was estimated to be in the 5% range (relative standard deviation). Homogeneity within the filters and among the filters was also tested using micro-XRF and found to be acceptable for the elements tested. The results of the tests carried out on the filters indicate that this approach is appropriate for large-scale production of similar filters for distribution as reference materials.  相似文献   

7.
The development of quality control materials for the determination of selected trace elements in air pollution studies is described. Three types of test samples were prepared for proficiency testing: (1) filters loaded with PM10 fraction of urban air particulate matter (APM) using high-volume air samplers, which were subsequently divided into smaller sections, (2) a bulk sample of APM collected in an automobile tunnel in Prague, and (3) simulated air filters loaded with APM using a wet deposition process. Homogeneity of the test samples was studied using instrumental neutron activation analysis, proton induced X-ray emission and atomic absorption spectrometry, and inductively coupled plasma optical emission spectrometry and mass spectrometry. Sufficiently homogeneous samples were prepared by all three procedures. The simulated air filters appeared to be the most suitable test samples for proficiency testing.  相似文献   

8.
Thermal neutron activation analysis technique was used in air pollution and aerosol elemental content and size distribution investigations. Air pollution samples were collected on Whatman 41 paper filters which were activated along with known quantities of standards in a flux of ~1013 n·cm?2·s?1. The activity of the samples was measured with a 40 cm3 Ge(Li) detector and analyzed with the computer program JANE, which identified the isotopes and found their quantities by normalization with the standard measurement results. Correlation between the various elements, in particular those belonging to dust from the desert and those considered typical urban air pollution, is investigated.  相似文献   

9.
Instrumental neutron activation analysis was used to determine the elemental concentrations in water and air solid samples collected on Nuclepore and Whatman filters from the Walker Branch Watershed. The results from this study show that the trace element concentrations removed by water from the watershed vary seasonally, as well as geographically. The data point up the usefulness and versatility of absolute neutron activation analysis. The NBS Standard Orchard Leaves was assayed in a similar manner, and good agreement was obtained between results here and standard values.  相似文献   

10.
At ITN, PM10 and PM2.5 aerosols were collected on Nuclepore® polycarbonate filters of 47 mm diameter, using Gent samplers at 15–17 l/min air flux. Filters were analyzed by INAA and PIXE. The availability of certified filters was very scarce, viz.: (1) fly ash embedded in a methyl cellulose 47 mm foil 10 µm thick, BCR CRM128, (2) particle-size reduced air particulate matter (APM) to simulate PM2.5 aerosol matter deposited on a 47 mm polycarbonate filter membrane, NIST SRM 2783. The high price and scarcity of APM standards did not permit their frequent use for analytical quality control. At ITN, to control the filter results' accuracy, the chemical elements potassium, iron and zinc, determined by both techniques, were systematically compared. After a few improvements introduced in INAA, this technique was now considered at ITN as the reference technique in air particulate measurements. Comparison of INAA to PIXE was discussed. Compared to previously reported situation it was concluded that the results were in better agreement for iron and zinc, and potassium values were still biased to the same extent as before.  相似文献   

11.
Hairless rats, clothes, human hair, filter paper and water were exposed to gaseous elemental iodine in a glass chamber for 60–120 minutes. The deposition of gaseous elemental iodine on skin and lung of rats, human hair, water, clothes and paper were investigated by measuring iodine content in the exposed material by epithermal neutron activation analysis (ENAA). For measurement of the iodine concentration in the chamber air, elemental iodine in the air was collected by continuously sucking air through an active charcoal column. The trapped iodine in the active charcoal was then determined by ENAA. The measured deposition velocity in the test chamber of gaseous elemental iodine on skin, clothing, hair and water ranges from 0.006 on filter paper and water to about 0.05 cm/s on skin and clothes. The variation of elemental iodine concentration in air of the glass chamber was investigated by collecting and analyzing air samples at various time intervals. The results show that the variation with time in the concentration of the iodine can be described by an exponential function.  相似文献   

12.
In order to find out if there is a relation between atmospheric particulate matter composition and human health effects, metals and other elements measurement are performed. Analysis of atmospheric aerosols collected in filters is the usual method to achieve this task. Biological monitors provide an advantageous alternative way of sampling, since there is no need of special sampling devices, and accumulation time can be as long as desired. In this study, Tillandsia usneoides a reliable air pollution biological monitor that occurs naturally throughout Mexico was used to monitor air quality of Tula–Tepeji corridor at central Mexico. This area is considered critical zone because of atmosphere contaminants high concentration. Some biomonitors were transplanted from a clean environment to four sites at the Tula corridor. Plants samples were collected every two weeks from February to April 2008. PM10 sampling in filters was also performed simultaneously at three locations where T. usneoides was transplanted, for a comparison. Chemical composition was determined by PIXE. Results showed that T. usneoides incorporates anthropogenic elements reaching maximal levels after 6 to 10 weeks approximately. Since results obtained with biomonitors agree with those obtained with aerosol filters, T. usneoides could be employed as a first approximation to provide insights of the atmospheric pollution level previous to a detailed study using filters.  相似文献   

13.
To clarify the magnitude of wash-out effect of rain on the elemental composition of airborne dust and the possible origin of the dust, the dust samples were collected with a high-volume air sampler at the JAERI-Tokai. The dust suspended in rain was also collected from rain by filtration. Up to 20 elements in both types of the dust were determined by instrumental neutron activation analysis. It was found that the elements determined could be classified into 3 groups from the elemental composition and the elemental correlation in both types of the dust samples.  相似文献   

14.
The modified BCR three-step sequential extraction procedure has been applied to two different samples of urban particulate matters (PM). The distribution of selected trace elements As, Cd, Cr, Mn, Ni, Pb, Zn was investigated and, in a comparative study, the presence of common organic air filters in extraction procedures was evaluated. Analytes in separate fractions were determined by ICP-OES and GFAAS, respectively, depending on concentration levels. While, due to air filters, a significant increase of some analytes mobility in individual fractions has been observed in case of the jet-milled PM (tunnel Letna), but in case of the PKC sample such effect was not found. The analyte impurities built in some filters has been tested, and the impact on the reliability of analyte results has been discussed. The arsenic species occurrence and their stability in presence of air filters (size 47 mm) were investigated in both urban PM samples as well, using HPLC-ICP-MS technique. Water soluble and by three-step BCR procedure extractable arsenic forms are shown in chromatograms  相似文献   

15.
Airborne particulate matter has been collected by a high volume and a Gent-type stacked filter unit (SFU) low volume sampler during the 2000-2001 period. The high volume sampler used S&S cellulosic and the SFU two Nuclepore polycarbonate filters to collect fine and coarse size fractions. The elemental analysis of the collected TSP, fine and coarse particles has been performed using instrumental neutron activation analysis and atomic absorption spectrometry. Twenty-two trace elements on Nuclepore and twenty-four elements on S&S filters have been measured. The collected data have been compared with the previous data of Tehran air and with other cities in the world. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

16.
An International Monitoring System (IMS) is being created to monitor the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Radionuclide aerosols will be monitored to provide positive proof of an atmospheric explosion. In addition, a group of laboratories will perform quality assurance and confirmatory analyses of samples of interest. The field and laboratory systems will perform gamma-ray spectrometric analysis of air filters. While laboratories may undertake additional analysis such as chemical separation and beta counting, the scope of the work reported here is to make evaluations with respect only to gamma-ray spectrometry. Activation products have not been completely considered and are shaded with uncertainty, from the probability of escape from an underground test and the dependence on the sub-surface elemental composition.  相似文献   

17.
A study on the concentration of natural and fallout radionuclides in environmental samples collected from different localities of Islamabad was performed. For the determination of gamma-emitters such as 238U, 232Th, 40K and 137Cs high purity germanium (HPGe) detector was used while for the analysis of 90Sr, a beta-emitter, liquid scintillation counting system was used. The indoor absorbed dose rate was measured by a CaF2 : Dy thermoluminescence detector. Other radiation parameters were also determined to evaluate the radiation hazard. All the results were well within the permissible limits showing that there is no radiation hazard in the environment of Islamabad.  相似文献   

18.
《Microchemical Journal》2011,97(2):386-390
In order to find out if there is a relation between atmospheric particulate matter composition and human health effects, metals and other elements measurement are performed. Analysis of atmospheric aerosols collected in filters is the usual method to achieve this task. Biological monitors provide an advantageous alternative way of sampling, since there is no need of special sampling devices, and accumulation time can be as long as desired. In this study, Tillandsia usneoides a reliable air pollution biological monitor that occurs naturally throughout Mexico was used to monitor air quality of Tula–Tepeji corridor at central Mexico. This area is considered critical zone because of atmosphere contaminants high concentration. Some biomonitors were transplanted from a clean environment to four sites at the Tula corridor. Plants samples were collected every two weeks from February to April 2008. PM10 sampling in filters was also performed simultaneously at three locations where T. usneoides was transplanted, for a comparison. Chemical composition was determined by PIXE. Results showed that T. usneoides incorporates anthropogenic elements reaching maximal levels after 6 to 10 weeks approximately. Since results obtained with biomonitors agree with those obtained with aerosol filters, T. usneoides could be employed as a first approximation to provide insights of the atmospheric pollution level previous to a detailed study using filters.  相似文献   

19.
A comparison study of the measurement of metals in ambient particulate matter collected on air filters, using energy-dispersive X-ray fluorescence (ED-XRF), laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) and wet chemical digestion followed by ICP-MS analysis according to the European ‘reference method’ EN14902, is presented. Whilst it is shown that the methods have a low systematic bias with respect to each other, overall they do show a high random variability, and when considered individually using regression methods, some analytes have shown bias with respect to the EN14902 method. The low systematic bias observed is not unexpected since both the ED-XRF and LA-ICP-MS methods have been calibrated using results from the EN14902 technique. The uncertainty of each analysis has been estimated and compared with the data quality objectives for uncertainty specified in the relevant European air quality legislation. This has tentatively shown that approximately 75% of the analyses using ED-XRF and LA-ICP-MS meet the requirements of the legislation. However, improvements in repeatability and calibration methods for both ED-XRF and LA-ICP-MS would be needed before these methods were truly applicable for routine use in air quality measurements of this type.  相似文献   

20.
A total of 44 pairs of airborne particulate matter samples were collected in the intersection of Simprug, Pondok Indah, South Jakarta. Sampling of airborne particulate matter was conducted in July 2008–July 2009 using a Gent stacked filter unit sampler in two size fractions of <2.5 µm (fine) and 2.5–10 µm (coarse). Mass concentrations, black carbon as well as elemental concentrations were investigated as a pre-study in step to the evaluation of air quality in these roadside areas. Black carbon was determined by reflectance and elemental analysis was performed using proton induced X-ray emission, PIXE. The data set of fine particulate matters obtained from the characterization was then analyzed using receptor modeling EPA PMF3 for source apportionment. Source apportionment identified 5 factors, i.e. soil (9.2 %), construction mixed with road dust (20.9 %), motor vehicles (31.5 %), biomass burning mixed with seasalt (30.9 %), and industry (7.5 %). Motor vehicles is the dominant sources that contributes to the fine particulate matter in Jakarta.  相似文献   

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