scholarly journals Characteristics of the elemental compositions of particulate matter at a subway platform using INAA and XRF

2011 ◽  
Vol 1 (1) ◽  
pp. 313-318
Author(s):  
J. M. Lim ◽  
J. H. Jeong ◽  
B. W. Jung ◽  
J. H. Lee ◽  
J. H. Moon ◽  
...  
Keyword(s):  
Enrichment Factors ◽  
Subway Station ◽  
Distribution Characteristics ◽  
Particle Fraction ◽  
Absolute Concentration ◽  
Average Standard Deviation ◽  
Relative Contribution ◽  
Pm2.5 And Pm10 ◽  
Crustal Enrichment Factors ◽  
Concentration Levels

Abstract In this study, a total of 21 elements were determined from PM2.5 and PM10 samples collected at one subway station using INAA and XRF. In order to assess the pollution status and distribution characteristics in a subway station, the absolute concentration levels, concentration ratios, and crustal enrichment factors of these elements were analyzed. PM2.5 concentrations in the subway station varied in the range of 24.8 to 72.6 μg m−3 (average  ±  standard deviation: 42.6 ± 10.6 μg m−3), while those of PM10 from 38.0 to 101 μg m−3 (67.2 ± 15.5 μg m−3). The relative contribution of elemental components in each particle fraction accounted for about 42 and 44%, respectively. Out of all metals, Fe was predominant to represent about 29 and 27% of each particle fraction. In contrast, the crustal sources were estimated to contribute to about 3.7 and 2.3% of the total Fe concentrations, respectively. Thus, one can conclude that considerable quantities of airborne Fe particles originated mainly from subway sources, probably due to the wearing of the steel products like wheel, rail, brake, etc.

scholarly journals Trace elements in South America aerosol during 20th century inferred from a Nevado Illimani ice core, Eastern Bolivian Andes (6350 m asl)

2003 ◽  
Vol 3 (5) ◽  
pp. 1337-1352 ◽  
Author(s):  
A. Correia ◽  
R. Freydier ◽  
R. J. Delmas ◽  
J. C. Simões ◽  
J.-D. Taupin ◽  
...  
Keyword(s):  
20Th Century ◽  
Ice Core ◽  
Enrichment Factors ◽  
High Temporal Resolution ◽  
Wet Season ◽  
Bolivian Andes ◽  
Icp Ms ◽  
Dry Seasons ◽  
Crustal Enrichment Factors

Abstract. A 137 m ice core drilled in 1999 from Eastern Bolivian Andes at the summit of Nevado Illimani (16º 37' S, 67º 46' W, 6350 m asl) was analyzed at high temporal resolution, allowing a characterization of trace elements in Andean aerosol trapped in the ice during the 20th century. The upper 50 m of the ice core were dated by multi-proxy analysis of stable isotopes (d18O and d2H), 137Cs and Ca+2 content, electrical conductivity, and insoluble microparticle content, together with reference historical horizons from atmospheric nuclear tests and known volcanic eruptions. This 50 m section corresponds to a record of environmental variations spanning about 80 years from 1919 to 1999. It was cut in 744 sub-samples under laminar flow in a clean bench, which were analyzed by Ion Chromatography for major ionic concentration, by a particle counter for insoluble aerosol content, and by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for the concentration of 45 chemical species from Li to U. This paper focuses on results of trace element concentrations measured by ICP-MS. The high temporal resolution used in the analyses allowed classifying samples as belonging to dry or wet seasons. During wet season elemental concentrations are low and samples show high crustal enrichment factors. During dry seasons the situation is opposite, with high elemental concentrations and low crustal enrichments. For example, with salt lakes as main sources in the region, average Li concentration during the 20th century is 0.035 and 0.90 ng g-1 for wet and dry seasons, respectively. Illimani average seasonal concentration ranges cover the spectrum of elemental concentration measurements at another Andean ice core site (Sajama) for most soil-related elements. Regional crustal dust load in the deposits was found to be overwhelming during dry season, obfuscating the contribution of biomass burning material. Marked temporal trends from the onset of 20th century to more recent years were identified for the concentrations of several trace species of anthropic origin, especially for Cu, As, Zn, Cd, Co, Ni and Cr. Among these elements, Cu shows average wet season crustal enrichment factors above 103, while the others range between 102 to about 5x102. P and K show moderate average wet season enrichment factors, suggesting an impact of natural biogenic emissions from the Amazon Basin. Pb has multiple anthropic sources in the region, from mining activities in the beginning of 20th century to automotive fuel after 1950s. From the large number of samples analyzed from Illimani, it was possible to derive an effective chemical characterization of the deposited background Andean soil dust aerosol during 20th century.

scholarly journals Geochemical Distribution Characteristics of Rare Earth Elements in Different Soil Profiles in Mun River Basin, Northeast Thailand

2020 ◽  
Vol 12 (2) ◽  
pp. 457 ◽  
Author(s):  
Wenxiang Zhou ◽  
Guilin Han ◽  
Man Liu ◽  
Chao Song ◽  
Xiaoqiang Li
Keyword(s):  
Rare Earth ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Rare Earth Elements ◽  
River Basin ◽  
Soil Ph ◽  
Enrichment Factors ◽  
Soil Profiles ◽  
Distribution Characteristics ◽  
Northeast Thailand

Exploring the distributions of rare earth elements (REEs) in soil profiles is essential to understanding how natural and anthropogenic factors influence the geochemical behaviors of REEs. This study aimed to learn about the distribution characteristics of REEs in soils, including their fractionation and enrichment, and to explore the influence of soil pH and soil organic carbon (SOC) on REEs. One hundred and three samples were collected from six soil profiles under different land uses (paddy field: T1, T3; forest land: T2, T6; wasteland: T4; building site: T5) in the Mun River Basin, Northeast Thailand. The average total REE contents (∑REE) are much lower (<80 mg kg−1) than that of Earth’s crust (153.80 mg kg−1) in soil profiles T2, T3, T4, and T6. The contents of REEs tend to increase slightly with depth in all soil profiles. The ratios of (La/Yb)N range from 0.35 to 0.96 in most samples, indicating that the enrichment of heavy REEs (HREEs) relative to light REEs (LREEs) is the main fractionation pattern. Samples from profile T2 show relatively obvious negative Ce anomalies (0.55–0.78) and positive Eu anomalies (1.41–1.56), but there are almost no anomalies of Ce and Eu in other soil profiles. Enrichment factors of LREEs (EFLREEs) range from 0.23 to 1.54 and EFHREEs range from 0.34 to 2.27, which demonstrates that all soil samples show no LREE enrichment and only parts of samples show minor HREE enrichment. Soil organic carbon (SOC) contents positively correlate with the enrichment factors of REEs (EFREE) in soil profiles T1 (R = 0.56, p < 0.01) and T6 (R = 0.71), while soil pH values correlate well with EFREE in soil profiles T2 (R = 0.75) and T4 (R = −0.66, p < 0.01), indicating the important influence of soil pH and SOC on the mobility of REEs in some soil profiles.

Nitrogen isotope fractionation as a tool for determining denitrification in constructed wetlands

2007 ◽  
Vol 56 (3) ◽  
pp. 167-173 ◽  
Author(s):  
A.K. Søvik ◽  
P.T. Mørkved
Keyword(s):  
Constructed Wetlands ◽  
Municipal Wastewater ◽  
Ph Value ◽  
Nitrogen Isotope ◽  
Enrichment Factors ◽  
Natural Abundance ◽  
Relative Contribution ◽  
Nitrogen Isotope Fractionation ◽  
15N Enrichment ◽  
Groundwater Systems

Constructed wetlands (CWs) treat municipal wastewater through the retention of nutrients and particles. The retention of nitrogen (N) was studied in the laboratory using columns and meso-scale trenches filled with shellsand and light-weight aggregates (LWA). The objective was to examine whether measuring the natural abundance of δ15N in NO−3 could be used to estimate the relative contribution of denitrification to the total NO−3 removal in these treatment systems. In both the columns and the trenches it was seen that denitrification was more efficient in shellsand and LWA collected from on-site treatment systems compared to new LWA. This was due to the high pH value (about 10) of new LWA. The enrichment factors (ε) from the column study were in general lower than values found in laboratory tests of isotope discrimination in denitrification, but similar to ε values found for denitrification in groundwater systems. No enrichment factors could be found for the trench study due to simultaneous denitrification and nitrification and inhomogeneous N transformation patterns. When NH+4 was partially nitrified in the upper parts of the trench, this diluted the 15N enrichment of NO−3 due to denitrification. Thus, in systems with high NH+4 concentrations and partial aerobic conditions, the method of natural abundance is not suitable for estimating the relative contribution of denitrification to the total NO−3 removal.

scholarly journals Trace elements in South America aerosol during 20<sup>th</sup> century inferred from a Nevado Illimani ice core, Eastern Bolivian Andes (6350 m a.s.l.)

2003 ◽  
Vol 3 (3) ◽  
pp. 2143-2177 ◽  
Author(s):  
A. Correia ◽  
R. Freydier ◽  
R. J. Delmas ◽  
J. C. Simões ◽  
J.-D. Taupin ◽  
...  
Keyword(s):  
20Th Century ◽  
Ice Core ◽  
Enrichment Factors ◽  
High Temporal Resolution ◽  
Wet Season ◽  
Bolivian Andes ◽  
Icp Ms ◽  
Dry Seasons ◽  
Crustal Enrichment Factors

Abstract. A 137 m ice core drilled in 1999 from Eastern Bolivian Andes at the summit of Nevado Illimani (16° 37' S, 67° 46' W, 6350 m a.s.l.) was analyzed at high temporal resolution, allowing a characterization of trace elements in Andean aerosol trapped in the ice during the 20th century. The upper 50 m of the ice core were dated by multi-proxy analysis of stable isotopes (d18O and d2H), 137Cs and Ca+2 content, electrical conductivity, and insoluble microparticle content, together with reference historical horizons from atmospheric nuclear tests and known volcanic eruptions. This 50 m section corresponds to a record of environmental variations spanning about 80 years from 1919 to 1999. It was cut in 744 sub-samples under laminar flow in a clean bench, which were analyzed by Ion Chromatography for major ionic concentration, by a particle counter for insoluble aerosol content, and by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for the concentration of 45 chemical species from Li to U. This paper focuses on results of trace element concentrations measured by ICP-MS. The high temporal resolution used in the analyses allowed classifying samples as belonging to dry or wet seasons. During wet season elemental concentrations are low and samples show high crustal enrichment factors. During dry seasons the situation is opposite, with high elemental concentrations and low crustal enrichments. For example, with salt lakes as main sources in the region, average Li concentration during the 20th century is 0.035 and 0.90 ng g−1 for wet and dry seasons, respectively. Illimani average seasonal concentration ranges cover the spectrum of elemental concentration measurements at another Andean ice core site (Sajama) for most soil-related elements. Regional crustal dust load in the deposits was found to be overwhelming during dry season, obfuscating the contribution of biomass burning material. Marked temporal trends from the onset of 20th century to more recent years were identified for the concentrations of several trace species of anthropic origin, especially for Cu, As, Zn, Cd, Co, Ni and Cr. Among these elements, Cu shows average wet season crustal enrichment factors above 103, while the others range between 102 to about 5×102. P and K show moderate average wet season enrichment factors, suggesting an impact of natural biogenic emissions from the Amazon Basin. Pb has multiple anthropic sources in the region, from mining activities in the beginning of 20th century to automotive fuel after 1950's. From the large number of samples analyzed from Illimani, it was possible to derive an effective chemical characterization of the deposited background Andean soil dust aerosol during 20th century.

Leak Detection for City Gas Pipelines Based on Instantaneous Energy Distribution Characteristics

2010 ◽  
Author(s):  
Zhigang Chen
Keyword(s):  
Energy Distribution ◽  
Distribution Characteristics ◽  
Physical Relationship ◽  
Correlative Analysis ◽  
Relative Contribution ◽  
Input And Output ◽  
City Gas ◽  
State Variation ◽  
Characteristic Signal ◽  
Instantaneous Energy

Because of the smallness of flux and low of pressure it is difficult to judge the characteristic signal when leak occurs. In this paper, a new instantaneous energy (IE) distribution characteristics extraction method based on Hilbert-Huang transformation (HHT) was presented and it was used to recognize different states in pipelines, such as, normal state, valve operating, compressor operating and leak. Firstly, the physical relationship between instantaneous energy and structural state variation of a system was analyzed theoretically. With HHT, the instantaneous energy distribution feature of an unstable pressure signal was obtained, according to the relative contribution method of the instantaneous energy, its noise was eliminated. In order to judge the leak the typical character of the instantaneous energy of pressure in the input and output ends was discussed using correlative analysis. The experimental results showed that this method is effective.

Elemental composition and bacterial incidence in firn-cores at Midre Lovénbreen glacier, Svalbard

Polar Record ◽  
2013 ◽  
Vol 51 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Shiv Mohan Singh ◽  
Puja Gawas-Sakhalkar ◽  
Simantini Naik ◽  
Rasik Ravindra ◽  
Jagdev Sharma ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Elemental Concentration ◽  
Salt Spray ◽  
Enrichment Factors ◽  
Sea Salt ◽  
Anthropogenic Sources ◽  
Total Count ◽  
Bacterial Cells ◽  
Inductively Coupled ◽  
Crustal Enrichment Factors

ABSTRACTThe present study was conducted to measure the elemental concentration and bacterial deposition in the firn-cores at the Midre Lovénbreen glacier, Svalbard. Firn-cores up to 1m deep were collected and divided into three subsections. These were subjected to elemental analysis using inductively coupled plasma mass spectroscopy (ICPMS). In all 20 elements were analysed. The crustal enrichment factors calculated for these elements on the basis of Fe values, demonstrate that the elements have derived from both crustal and anthropogenic sources. For certain elements there also exists a possibility of input from sea salt spray. Total bacterial counts in these firn samples ranged from 1.03 × 105to 3.67 × 105per ml of meltwater. Culturability of these bacterial cells, in comparison to the total count was very low. At 4°C the maximum culturability was <1.4% of the total count while at 15°C it was still lower (~1%).

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