Enrichment Factors Of Elements Research Articles

Mass size distributions of elemental aerosols in industrial area

Outdoor aerosol particles were characterized in industrial area of Samalut city (El-minia/Egypt) using low pressure Berner cascade impactor as an aerosol sampler. The impactor operates at 1.7m3/h flow rate. Seven elements were investigated including Ca, Ba, Fe, K, Cu, Mn and Pb using atomic absorption technique. The mean mass concentrations of the elements ranged from 0.42ng/m3 (for Ba) to 89.62ng/m3 (for Fe). The mass size distributions of the investigated elements were bi-modal log normal distribution corresponding to the accumulation and coarse modes. The enrichment factors of elements indicate that Ca, Ba, Fe, K, Cu and Mn are mainly emitted into the atmosphere from soil sources while Pb is mostly due to anthropogenic sources.

Incremental effect of festive biomass burning on wintertime PM10 in Brahmaputra Valley of Northeast India

PM10 concentration was monitored at a receptor site in the Brahmaputra Valley during a unique, local, episodic festive biomass burning called meji burning. Mean mass concentration of PM10 during monitoring was found to be 149±45μgm−3 with maximum and minimum concentrations of 293μgm−3 and 93μgm−3 respectively. Elemental analysis by Energy Dispersive X-ray Spectrometer (EDX) revealed high carbonaceous and Br content in PM10 samples. Particulate carbon showed high significant correlation with PM10 and dominance in samples taken during night time. Back trajectory analysis supported long range transport of carbonaceous aerosol from the Indo-Gangetic Plain (IGP) to the region under study. Prevailing meteorology – thermal inversion and low mixing heights – was found to have a strong influence on PM10 levels in the post festive burning period. Enrichment factors of several elements ranged above thousand which indicated a strong influence of anthropogenic activities and input of aged particulates driven from long distance. Incremental effect of meji burning, which we coined as Meji Burning Induced Enrichments (MBIEs), was calculated. MBIE values supported incremental effects explicitly.

Elemental characterization of coal, fly ash, and bottom ash using an energy dispersive X-ray fluorescence technique

A total of 18 elements viz. Si, Al, Fe, Ca, Mg, K, Na, Sr, V, Zn, Mn, Cr, Cu, Pb, Ni, Co, As and Cd were analyzed in coal, fly ash and bottom ash samples collected across India using an EDXRF technique. Various indices such as element enrichment ratio, enrichment factor (with respect to crustal average) and mineral composition were calculated. Around 95% of mass was reconstructed using the concentration of elements in this study for fly and bottom ash.

Control factors on the composition of superficial sediments in estuaries of the coast of Huelva (SW Spain): a statistical approach.

The geochemical composition of surface sediments has been analyzed for the following three river estuaries located in the Huelva coast (SW Spain): Guadiana, Piedras and Tinto-Odiel (Ria de Huelva), which represent an area strongly affected by mining activity, mainly for Cu exploitation in the Iberian Pyrite Belt. The main goal of the present study was to evaluate the water and sediment quality of the three estuary systems, which have been subject to different types of anthropogenic activity. Enrichment factors (EF) for several elements were determined for each system, using as reference the composition of the sediments from the Huelva Ria, prior to the intensive mining and industrial activity. Statistical treatment based on factorial analysis allowed establishing the origin of the elements and the main control factors of their geochemical behaviour in the estuarine systems. The estuary of Tinto-Odiel rivers (Ria de Huelva) presents high metal concentrations and strong EF for metals related to acid mine drainage, namely Cu (EF of 75,6), Zn (EF of 36,9), and Pb (EF of 58), indicating severe environmental quality problems. On the contrary, the sediments of the Guadiana and Piedras rivers show no significant EF. Here, the obtained results indicate the absence of antropic metallic contributions, which permits the maintenance of the environmental quality of both systems. Thus, the present study revealed the environmental quality problems of the sediments from Tinto-Odiel estuary, while in Guadiana and Piedras there are no significant metallic contributions, ensuring the maintenance of the their environmental quality.

Elemental Spatiotemporal Variations of Total Suspended Particles in Jeddah City

Elements associated with total suspended particulate matter (TSP) in Jeddah city were determined. Using high-volume samplers, TSP samples were simultaneously collected over a one-year period from seven sampling sites. Samples were analyzed for Al, Ba, Ca, Cu, Mg, Fe, Mn, Zn, Ti, V, Cr, Co, Ni, As, and Sr. Results revealed great dependence of element contents on spatial and temporal variations. Two sites characterized by busy roads, workshops, heavy population, and heavy trucking have high levels of all measured elements. Concentrations of most elements at the two sites exhibit strong spatial gradients and concentrations of elements at these sites are higher than other locations. The highest concentrations of elements were observed during June–August because of dust storms, significant increase in energy consumption, and active surface winds. Enrichment factors of elements at the high-level sites have values in the range >10~60 while for Cu and Zn the enrichment factors are much higher (~0–>700) indicating that greater percentage of TSP composition for these three elements in air comes from anthropogenic activities.

The impact of poultry litter application on sediment chemistry of the Broadkill River estuary system, Delaware

This project examined the impact of long-term poultry litter application on the chemical signatures of As, Cu, Zn, and P in stream sediments of the Broadkill River watershed within the Delmarva Peninsula, a region of intense poultry production. Thirty-seven sediment samples were collected from Broadkill River drainage systems and analyzed for litter-derived elements (As, Cu, Zn, P) and basic soil parameters such as particle size distribution, organic matter, and soluble salts. Results showed that concentrations of elements in stream sediments are approximately log-normally distributed. Spatial variability in concentrations of elements was evident, with most elements increasing in concentration and enrichment from upgradient headwaters to downgradient reaches draining predominantly agricultural areas. Results of correlation analyses showed positive significant correlation among elements; elements were also positively correlated with percent clay and silt in the sediment. Using GIS maps with overlays of hydrology and land use activities, statistical correlations between As, Cu, Zn, and P enrichment factors and land use were examined. Results showed statistically significant relationships between As, Mn, and Zn enrichment factors and residential areas within the watershed, but did not show a statistically significant relationship between element enrichment factors and agricultural land use. Factors that complicate this type of landscape-scale study include the presence of poultry processing plants, impoundments, changes in land use over time, and the influence of tides, all of which can have direct and indirect influences on element mobility.

Atmospheric mercury and fine particulate matter in coastal New England: Implications for mercury and trace element sources in the northeastern United States

Intensive sampling of ambient atmospheric fine particulate matter was conducted at Woods Hole, Massachusetts over a four-month period from 3 April to 29 July, 2008, in conjunction with year-long deployment of the USGS Mobile Mercury Lab. Results were obtained for trace elements in fine particulate matter concurrently with determination of ambient atmospheric mercury speciation and concentrations of ancillary gasses (SO2, NOx, and O3). For particulate matter, trace element enrichment factors greater than 10 relative to crustal background values were found for As, Bi, Cd, Cu, Hg, Pb, Sb, V, and Zn, indicating contribution of these elements by anthropogenic sources. For other elements, enrichments are consistent with natural marine (Na, Ca, Mg, Sr) or crustal (Ba, Ce, Co, Cs, Fe, Ga, La, Rb, Sc, Th, Ti, U, Y) sources, respectively. Positive matrix factorization was used together with concentration weighted air-mass back trajectories to better define element sources and their locations. Our analysis, based on events exhibiting the 10% highest PM2.5 contributions for each source category, identifies coal-fired power stations concentrated in the U.S. Ohio Valley, metal smelting in eastern Canada, and marine and crustal sources showing surprisingly similar back trajectories, at times each sampling Atlantic coastal airsheds. This pattern is consistent with contribution of Saharan dust by a summer maximum at the latitude of Florida and northward transport up the Atlantic Coast by clockwise circulation of the summer Bermuda High. Results for mercury speciation show diurnal production of RGM by photochemical oxidation of Hg° in a marine environment, and periodic traverse of the study area by correlated RGM-SO2(NOx) plumes, indicative of coal combustion sources.

Heavy metals pollution origin in the bed sediments of Aswan high dam reservoir: lithogenic or anthropogenic sources

Heavy metals are present in aquatic sediments as a result of chemical leaching of bed rocks (Lithogenic source), and discharge of urban and industrial wastewaters (Anthropogenic sources). It is important to provide information about the source of heavy metals pollution because high levels of heavy metals can often be attributed to anthropogenic influences, rather than natural enrichment of the sediment by geological weathering (Lithogenic influences). This study was initiated with the objective of determining the origin of heavy metals pollutants in the bed sediments of Aswan High Dam Reservoir (AHD) and to evaluates their environmental risk in reservoir water and its potential use (benefits and risks) in agricultural land. Total metals concentration, the element Enrichment Factor (EF) and the sequential extractions of heavy metals (speciation) were determined in addition to pH, organic matter content and grain size distribution. The results indicated that the total metal contents varied in the following ranges (in mg/kg): Al (1165-18000), Cd (0.62-2.17), Co (11-47), Cr (12-63), Cu (80-261), Fe (3027-36651), Mn (93-1908), Ni (11-58), Pb (7-29) and Zn (98-208). The enrichment factor for all metals in sediment was found to be low and the heavy metals speciation revealed that the exchangeable and carbonate bound fractions are entirely insignificant. The results revealed no anthropogenic contribution of heavy metals and the chemical weathering is a primary factor that controls the concentrations of metals in the bed sediments of the Reservoir. The results indicated that metals in the bed sediments of the reservoir did not represent environmental pollution risk and are derived from lithogenic (natural) processes (i.e weathering and soil formation). The bed sediments of the reservoir were found in the alkaline range and are promoting heavy metals precipitation. Thus it was recommended to use these sediments in soil amendment.

Spatial geochemical variation of major and trace elements in the marine sediments of Mumbai Harbor Bay

The resulting concentration data sets of major (Na, K, Mg, Ca and Fe) and trace elements (Cu, Ni, Co and Mn) in bed and suspended sediments were used to evaluate the enrichment factor for anthropogenic influences and principal component analysis for identifying the origin of source contributions in the studied area. Normalization of metals to Fe indicated that high enrichment factors in the bed sediment were in the order of Co > Cu > Na > Ca > Ni except Mg, K and Mn while for suspended sediments, only Co has a high enrichment factor. High enrichment of Co and Cu reflected the contamination of sediments from anthropogenic sources. The high influence of Na and Ca in sediments may be caused for seawater salinization factor. A significant positive correlation among enrichment factors of various elements of interest suggests a common origin/identical behavior during transport in the sediment system.

Distribution of trace elements in feed coal and combustion residues from two coal-fired power plants at Huainan, Anhui, China

The rapid expansion of coal-fired power plants (CFPPs) in China has produced huge volume of toxic elements associated combustion residues, which pose great threat to local environment. In this study, feed coal, fly ash, bottom ash and FGD gypsum samples were collected from two different CFPPs at Huainan, Anhui, China. Feed coal and combustion residues were morphologically and mineralogically characterized by scanning electron microscopy equipped with energy-dispersive microanalyser and X-ray diffraction. Concentrations of thirteen major and trace elements in these samples were determined by inductively coupled plasma atomic emission spectrometry (B, Ti, Mn, Ni and Zn), inductively coupled plasma mass spectrometry (Cd, Co, Cr, Cu, Pb, Sn and V) and atomic fluorescence spectroscopy (As). The results show that most of the trace elements were concentrated in the fly ash, only Fe and Mn were enriched in the bottom ash. The diameters of ash particles removed by the electrostatic precipitator were in an inverse relationship with the enrichment factors of most trace elements. To address possible exposure of combustion residues in the environment, laboratory controlled leaching tests were carried out on fly ash and gypsum to understand the environmental behaviors of these elements. Both fly ash and gypsum were identified as not-hazardous wastes.

Impact of a dust storm on characteristics of particle matter (PM) in Guangzhou, China

A strong dust-storm (23–25 April, 2009) occurred in the provinces of Inner Mongolia, Gansu, and Shanxi, North China. Cities along the storm path (from north to south: Xi’ning, Lanzhou, Chengdu, Changsha, and Guangzhou) all experienced a sharp increase in particle matter (PM10) concentration. This is the first case that an Asian dust storm hit Guangzhou in Southern China. The impacts of dust storm on the characteristics of PM were investigated using samples collected in Guangzhou during 27–29 April, 2009. In addition, the mass concentration and chemical composition during a normal non-dust period (12–14 May, 2009) were compared with those in dust period. The results show that the concentration of PM10 during the dust episode (0.231 mg m−3) was twice higher than that in the non-dust episode (0.103 mg m−3). Chemical analysis showed that concentrations of metal elements, enrichment factors of metal elements, and soluble ions during the dust episode were very different from those of non-dust. The total concentration of metal elements content in PM10 was 53.5 μg m−3 in the dust episode, which is about two times higher than that in non-dust episode (28.5 μg m−3). Increases in concentrations of Na, Ti, Zn, Cu, and Cr ranged from zero to 100% during the dust episode. However, the enrichment factors in non-dust episode were higher than that in dust-storm period, indicating that the above five chemicals originated mainly from local sources in Guangzhou. The concentrations of K, Mg, Al, Fe, Mn, V, and Co increased by over 100% in the dust episode, indicating their origins of remote sources. In the dust period, some water-soluble ions increased in PM10, but the main components in PM10 were SO4 −, NO3 − and NH4 +. At last, we assessed the sources of dusts by analyzing synoptic situation and back trajectories of air mass in Guangzhou, and demonstrated that the main source of the dust storm was from Mongolia.

Spatial distribution and sources identification of elements in PM2.5 among the coastal city group in the Western Taiwan Strait region, China

The main purpose of this study was to investigate the spatial variations of 20 elements (Al, Si, Ti, Ca, Fe, Mg, Cr, Mn, Ni, P, S, K, Cu, Cl, V, Se, Br, As, Zn, and Pb) in PM2.5 (particle matters≤2.5μm in aerodynamic diameter) in the coastal city group in the Western Taiwan Strait (WTS) region, China during spring 2011. The average PM2.5 mass concentration at 13 sites was 77.0μg/m3 and the elemental fraction accounted for about 10–20%. Multivariate analyses (principal component analysis and cluster analysis) and a correlation matrix were used to identify the sources of elements in PM2.5. The results revealed that the elements originated mainly from traffic emissions, coal combustion, pyrometallurgical processes, and crustal sources. Spatially, the concentrations of elements were generally higher in several rapidly growing locations, and the enrichment factors (EFs) for most elements were much higher at the northern sites than those at the southern sites, suggesting that the air quality in the northern part of the study area was strongly affected by anthropogenic activity. Backward wind trajectory analysis during the sampling period indicated that the concentrations of elements in PM2.5 in the WTS region were greatly impacted by dust particles transported from Northern China in spring.

2007년 봄철 대전지역에서 발생한 황사 및 대기부유물의 지구화학적 특성 및 중 금속의 오염도

본 연구에서는 2007년도 봄철 대전 지역에서 발생한 황사(황사 기간) 및 대기부유물(비황사 기간)의 미량원소의 지구화학적 특성과 정량적 오염정도를 평가하였다. 황사 내 미량원소의 함량은 황사발원지 토양의 평균 함량에 비하여 수십에서 수백 배 높은 함량을 보여주고 있으며, 비황사 시기의 대기부유물에서도 유사한 특성을 보이고 있어, 황사 시기뿐만 아니라 비황사 시기에도 중국으로부터 이동되는 오염물질의 영향을 받고 있음을 지시하고 있다. 입도별 미량원소의 함량은 <TEX>$PM_{2.5}$</TEX>에서 Cr, Cu, Pb, Zn, V, S, As, Cd, Co, Ni, Mo, Sb, Cs, Rb, Th, Sc, Y 등이, 그리고 TSP에서는 Zr, Sr, Ba, Li, Th, U 등의 함량이 가장 높은 것으로 나타났다. 황사의 S, Cd, Mo, Zn, Pb, Sb, Cu 및 Zr 함량은대기부유물과 큰 차이를 보이지 않으나, 대기오염으로 부화가 발생하지 않는 Li, Cs, Co, U, Cr, Ni, Rb, V, Th, Y, Sr, Sc 등은 황사에서 2-4.2배 높아졌다. 그러므로 이들 원소들을 황사발생의 지시원소로 사용할 수 있으며, 특히 Sr, V, Cr 및 Li 등은 황사 발생을 판단하기 위한 지시원소로 사용하기에 적합한 것으로 보인다. 한편 황사의 이동경로에 따른 미량원소의 함량을 살펴본 결과, 중국의 대도시 및 산업단지를 경유하여 국내 유입된 황사가, 북한을 경유하여 국내에 도달한 황사에 비해서, S, Cd, Zn, Pb, Cu, Mo 및 As 함량이 높게 나타나, 황사의 이동경로가 이들 미량원소 오염 여부 및 오염도를 결정하는데 중요한 역할을 하는 것으로 판단된다. 황사 및 대기부유물 내 미량원소의 부화지수(Enrichment factor)을 기준으로 오염정도를 분류한 결과, 환경재해 측면에서 가장 문제가 되는 미량원소는 S, Zn, Cu, Pb, As, Mo, Cd이며, 이들은 인간의 건강 뿐만 아니라, 오랜 기간 토양과 수계환경에 퇴적될 경우 환경오염으로 인한 주변 생태계에 해로운 영향을 미치게 될 것으로 판단된다. We evaluated the geochemical characteristics and their potential pollution of Asian Dusts in Daejeon, Korea during spring 2007. Compared with the chemical compositions of soils in source area of Asian Dust, those of aerosols in Daejeon were enriched with trace elements (ten to hundred fold), inferring that pollutants from China have affected on local environment in adjoining country such as Korea. Chemical analysis of aerosols during Asian dust showed that fine particles (<TEX>$PM_{2.5}$</TEX>) contained high contents of trace elements such as Cr, Cu, Pb, Zn, V, S, As, Cd, Co, Ni, Mo, Sb, Cs, Rb, Th, Sc and Y. In the case of TSP (Total Suspended Particle), Zr, Sr, Ba, Li, Th and U were contained much more than other trace elements. The contents of some elements (i.e. Li, Cs, Co, U, Cr, Ni, Rb, V, Th, Y, Sr and Sc) in aerosols collected in Asian Dust period, which are not likely enriched by air pollutants, were higher (2 - 4.2 fold) than those in Non Asian Dust period, indicating that these elements could be used as indicator elements for determining the occurrence of Asian Dust phenomena (especially, Sr, V, Cr & Li). In the case of Asian Dust coming through the big cities and/or industrial areas of China, the domestic aerosols had higher contents of trace elements (such as S, Cd, Zn, Pb, Cu, Mo and As) than those from Northeastern China via North Korea, indicating that the transportation courses of air mass are very important to determine the pollution degrees. Using the enrichment factors of trace elements in aerosols during Asian Dust and Non Asian Dust, we identified that some elements (i.e. S, Zn, Cu, Pb, As, Mo and Cd) were most problematic in terms of environmental hazard aspects, and these elements could affect adverse effects on human health as well as ecosystem and surface environment (soil and water) through long-lived precipitation.

Long-term dust climatology in the western United States reconstructed from routine aerosol ground monitoring

Abstract. This study introduces an observation-based dust identification approach and applies it to reconstruct long-term dust climatology in the western United States. Long-term dust climatology is important for quantifying the effects of atmospheric aerosols on regional and global climate. Although many routine aerosol monitoring networks exist, it is often difficult to obtain dust records from these networks, because these monitors are either deployed far away from dust active regions (most likely collocated with dense population) or contaminated by anthropogenic sources and other natural sources, such as wildfires and vegetation detritus. Here we propose an approach to identify local dust events relying solely on aerosol mass and composition from general-purpose aerosol measurements. Through analyzing the chemical and physical characteristics of aerosol observations during satellite-detected dust episodes, we select five indicators to be used to identify local dust records: (1) high PM10 concentrations; (2) low PM2.5/PM10 ratio; (3) higher concentrations and percentage of crustal elements; (4) lower percentage of anthropogenic pollutants; and (5) low enrichment factors of anthropogenic elements. After establishing these identification criteria, we conduct hierarchical cluster analysis for all validated aerosol measurement data over 68 IMPROVE sites in the western United States. A total of 182 local dust events were identified over 30 of the 68 locations from 2000 to 2007. These locations are either close to the four US Deserts, namely the Great Basin Desert, the Mojave Desert, the Sonoran Desert, and the Chihuahuan Desert, or in the high wind power region (Colorado). During the eight-year study period, the total number of dust events displays an interesting four-year activity cycle (one in 2000–2003 and the other in 2004–2007). The years of 2003, 2002 and 2007 are the three most active dust periods, with 46, 31 and 24 recorded dust events, respectively, while the years of 2000, 2004 and 2005 are the calmest periods, all with single digit dust records. Among these deserts, the Chihuahuan Desert (59 cases) and the Sonoran Desert (62 cases) are by far the most active source regions. In general, the Chihuahuan Desert dominates dust activities in the first half of the eight-year period while the Sonoran Desert in the second half. The monthly frequency of dust events shows a peak from March to July and a second peak in autumn from September to November. The large quantity of dust events occurring in summertime also suggests the prevailing impact of windblown dust across the year. This seasonal variation is consistent with previous model simulations over the United States.

Multi-elemental characterization of tunnel and road dusts in Houston, Texas using dynamic reaction cell-quadrupole-inductively coupled plasma–mass spectrometry: Evidence for the release of platinum group and anthropogenic metals from motor vehicles

Platinum group elements (PGEs) including Rh, Pd, and Pt are important tracers for vehicular emissions, though their measurement is often challenging and difficult to replicate in environmental campaigns. These challenges arise from sample preparation steps required for PGE quantitation, which often cause severe isobaric interferences and spectral overlaps from polyatomic species of other anthropogenically emitted metals. Consequently, most previous road dust studies have either only quantified PGEs or included a small number of anthropogenic elements. Therefore a novel analytical method was developed to simultaneously measure PGEs, lanthanoids, transition and main group elements to comprehensively characterize the elemental composition of urban road and tunnel dusts. Dust samples collected from the vicinity of high-traffic roadways and a busy underwater tunnel restricted to single-axle (predominantly gasoline-driven) vehicles in Houston, TX were analyzed for 45 metals with the newly developed method using dynamic reaction cell-quadrupole-inductively coupled plasma–mass spectrometry (DRC-q-ICP–MS). Average Rh, Pd and Pt concentrations were 152±52, 770±208 and 529±130ngg−1 respectively in tunnel dusts while they varied between 6 and 8ngg−1, 10 and 88ngg−1 and 35 and 131ngg−1 in surface road dusts. Elemental ratios and enrichment factors demonstrated that PGEs in dusts originated from autocatalyst attrition/abrasion. Strong evidence is also presented for mobile source emissions of Cu, Zn, Ga, As, Mo, Cd, Sn, Sb, Ba, W and Pb. However, all other elements including rare earths most likely arose from weathering, erosion and resuspension of crustal material. These are the first such detailed measurements in Houston, the largest city in TX and fourth largest in the United States. We posit that such investigations will assist in better understanding PGE concentrations in urban environments while providing elemental data necessary to better understand anthropogenic influences on their biogeochemical cycling.

Effects of Wastewater Irrigation on Chemical and Physical Properties of Petroselinum crispum

The present study was carried out to assess the impact of wastewater on parsley (Petroselinum crispum). The parameters determined for soil were pH, electrical conductivity (EC), soil organic matter (SOM), nutrient elements (Ca, Mg, Na, K, Mn, Cu, Zn, and Fe), and heavy metals (Cd, Cr, Ni, and Pb), while the parameters determined for the plant included pigment content, dry matter, nutrient element, and heavy metals. SOM, EC, and clay contents were higher, and pH was slightly acidic in soil treated with wastewater compared to control soil. The enrichment factors (EF) of the nutrient elements in contaminated soil are in the sequence of Na (2) > Ca (1.32) > Mn = Mg (1.17) > Cu (1.11) > Zn (1.08) > Fe (1.07) > K (0.93), while EF in parsley are Na (6.63) > Ca (1.60) > Mg (1.34) > Zn (1.15) > Fe (0.95) > Cu = K (0.90) > Mn (0.85). Application of wastewater significantly decreased dry matter, while photosynthetic pigment content increased in parsley. The enrichment of the heavy metals is in the sequence: Cd (1.142) > Pb (1.131) > Ni (1.112) > Cr (1.095). P. crispum shows a high transfer factor (TF > 1) for Cd signifying a high mobility of Cd from soil to plant. Thus, although the wastewater irrigation in parsley production aims to produce socioeconomic benefits, study results indicated that municipal wastewater is not suitable for irrigation of parsley because it has negative effects on plant and causes heavy metal accumulation.

Distribution, enrichment and principal component analysis for possible sources of naturally occurring and anthropogenic radionuclides in the agricultural soil of Punjab state, India

Enrichment factor (EF) of elements including geo-accumulation indices for soil quality and principal component analysis (PCA) were used to identify the contributions of the origin of sources in the studied area. Results of (40)K, (137)Cs, (238)U and (232)Th including their decay series isotopes in the agricultural soil of Mansa and Bathinda districts in the state of Punjab were presented and discussed. The measured mean radioactivity concentrations for (238)U, (232)Th and (40)K in the agricultural soil of the studied area differed from nationwide average crustal abundances by 51, 17 and 43 %, respectively. The sequence of the EFs of radionuclides in soil from the greatest to the least was found to be (238)U > (40)K > (226)Ra > (137)Cs > (232)Th > (228)Ra. Even though the enrichment of naturally occurring radionuclides was found to be higher, they remained to be in I(geo) class of '0', indicating that the soil is uncontaminated with respect to these radionuclides. Among non-metals, N showed the highest EF and belonged to I(geo) class of '2', indicating that soil is moderately contaminated due to intrusion of fertiliser. The resulting data set of elemental contents in soil was also interpreted by PCA, which facilitates identification of the different groups of correlated elements. The levels of the (40)K, (238)U and (232)Th radionuclides showed a significant positive correlation with each other, suggesting a similar origin of their geochemical sources and identical behaviour during transport in the soil system.

Use of chemical fractionation to understand partitioning of biomass ash constituents during co-firing in fluidized bed combustion

Three species of biomass origin (straw pellets, olive cake and wood pellets) and two coals from different countries (Coal Polish and Coal Colombian) have been studied to understand the fate of their ash forming matter during the combustion process and to investigate the influence of co-firing biomass with coal. Three different approaches to investigate the ash behaviour were employed: (1) chemical fractionation analysis to evaluate the association/reactivity of ash forming elements in the fuels as a prediction tool, (2) establishment of elements partitioning in ash streams produced in the combustion and co-combustion trials, and (3) evaluation of enrichment factors of elements in the ash streams. The chemical fractionation analysis was applied to all fuels used to evaluate how the association/reactivity of elements making up ash may influence their behaviour during combustion. Combustion tests were carried out on a pilot scale fluidized bed combustor (FBC). Four ash streams were obtained at different locations. The uncertainty of measurements was estimated allowing a critical evaluation of mass balances over the combustion system and the partitioning of elements in the ash streams. The enrichment factors of elements in the several ash streams were estimated, incorporating uncertainties associated with analytical measurements. Results obtained showed that for FBC the relation between the chemical fractionation and the experimental partitioning is strongly affected by elutriation of particles. The element enrichment factor estimated for each ash stream, using Al as a reference element, revealed better correlations with the elements reactivity obtained by chemical fractionation because it overcomes particles elutriation effects. Nevertheless, it was observed that the reactivity estimated by chemical fractionation could not be solely interpreted as tendency of the elements to volatilize on FBC system, as reaction in bed zone of boiler may also occur retaining reactive elements.

Characterization of PM10 source profiles for fugitive dust in Fushun-a city famous for coal

Abstract A total of 120 fugitive dust samples were collected to acquire chemical source profiles of PM 10 in Fushun including 27 soil dust samples, 32 road dust samples, 19 construction dust samples, 13 coal storage pile samples, 2 cement production samples, 13 coal-fired power plant fly ash samples, 5 fly ash samples from iron smelt plant and 9 samples from industrial raw material and production piles. The samples were classified as 20 subtypes. The dust samples were dried, sieved, resuspended and sampled through a PM 10 inlet onto filters, and then chemically analyzed. Inductively coupled plasma-atomic emission spectrometry, ion chromatograph and thermal/optical reflectance methods were adopted for analyzing twenty elements including Na, Mg, Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Pb and Hg and nine ions including Na + , NH 4 + , K + , Mg 2+ , Ca 2+ , F − , Cl − , NO 3 − and SO 4 2− as well as OC and EC, respectively. The chemical compositions were compared for 20 subtypes. Si and Ca were the most abundant elements in all the fugitive dust profiles. Enrichment factors of elements in fly ashes compared to raw coal were calculated with Fe as reference element. The highest enriched elements were Ni, Cu, Zn and Pb. Significant difference existed among PM 10 profiles with the coefficient of divergence values ranging from 0.28 to 0.78. Profiles were compared with others. Si exhibited lower content in this study for soil and road dust while EC and Cr showed much higher content compared to others indicating the influence of coal mining and industries activities in Fushun. This was validated by source signatures analysis which indicated almost all the fugitive dust were relative to coal and may also be influenced by metallurgy. The ratios of Mn/V, V/Ni, Zn/Pb and Zn/Cd were calculated for source identification. Elemental ratios may vary widely even for the same source types with different processing courses. Chemical profiles of fugitive dust should be established based on characteristic sources for a specific region and updated timely.

Air quality and elemental enrichment factors of aerosol particulate matter in Riyadh City, Saudi Arabia

Air particulate matter (PM) samples were collected from June 2006 to May 2007 for determination of chemical elements. PM samples were taken in two size fractions (PM2.5 and PM10) with MiniVolume air samplers on rooftops of various buildings (15–25 m above ground) in the city of Riyadh. The samples were subjected to X-ray fluorescence analysis to measure major (Na, Mg, Al, K, Ca, Si, P, S, and Fe) and trace elements (Mn, Ni, Cu, Zn, and Ba). The results showed that the PM concentrations were higher for PM10 compared to PM2.5, indicating that the major PM source was local dust. Also the spatial distribution with high PM concentrations was observed in the south and southeast of the city and the lowest levels were in the center and northeast of the city. This spatial distribution was attributed to different factors such as wind direction and velocity, emission from cement factories, and the presence of buildings, trees, and paved streets that reduce the amount of dust resuspended into the atmosphere. The air quality of the city was found to range from good to hazardous based on PM2.5, and from good to very hazardous based on PM10. The element-enrichment factors revealed two element groups according to their changing spatial behavior. The first group showed no significant spatial changes indicating they have the same common source. The second group (mainly S and Ni) exhibited significant changes as expected from anthropogenic inputs. The origin of S is possibly a combination of minerals (CaSO4) and fossil fuel combustion. The source of Ni is probably from fossil fuel combustion.