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Influence of urban activities on polycyclic aromatic hydrocarbons in precipitation: Distribution, sources and depositional flux in a developing metropolis, Fortaleza, Brazil

Cavalcante, Rivelino M.; Sousa, Francisco W.; Nascimento, Ronaldo F.; Silveira, Edilberto R.; Viana, Rommel B.
Fonte: ELSEVIER SCIENCE BV; AMSTERDAM Publicador: ELSEVIER SCIENCE BV; AMSTERDAM
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.08%
We measured polycyclic aromatic hydrocarbons (PAHs) in bulk precipitation in the Fortaleza metropolitan area, Ceara, Brazil, for the first time. Because little information is available concerning PAHs in tropical climatic regions, we assessed their spatial distribution and possible sources and the influence of urban activities on the depositional fluxes of PAHs in bulk precipitation. The concentrations of individual and total PAHs (Sigma(PAHs)) in bulk precipitation ranged from undetectable to 133.9 ng.L-1 and from 202.6 to 674.8 ng.L-1, respectively. The plume of highest concentrations was most intense in a zone with heavy automobile traffic and favorable topography for the concentration of emitted pollutants. The depositional fluxes of PAHs in bulk precipitation calculated in this study (undetectable to 0.87 mu g.m(-2).month(-1)) are 4 to 27 times smaller than those reported from tourist sites and industrial and urban areas in the Northern Hemisphere. Diagnostic ratio analyses of PAH samples showed that the major source of emissions is gasoline exhaust, with a small percentage originating from diesel fuel. Contributions from coal and wood combustion were also found. Major economic activities appear to contribute to pollutant emissions. (C) 2011 Elsevier B.V. All rights reserved.; CNPq; CNPq; FUNCAP; FUNCAP

Caracterização da deposição atmosférica e aporte de espécies químicas no principal corpo aquático da cidade de São José do Rio Preto, SP

Medeiros, Fabio Henrique
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: 95 f. : il. color.
POR
Relevância na Pesquisa
46.24%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Pós-graduação em Química - IBILCE; A atmosfera tem grande importância no transporte e distribuição de elementos oriundos de atividades naturais ou antrópicas, sobre a superfície terrestre, sendo a deposição atmosférica o principal processo de ciclagem dos compostos químicos entre os compartimentos ambientais. A cidade de São José do Rio Preto (SJRP) possui um pequeno parque industrial, conta com a presença de duas rodovias de grande tráfego, a rodovia Washington Luís (SP-310) e a rodovia Transbrasiliana (BR-153), e em termos agrícolas a região é responsável por 12% da produção de etanol do estado, e destacando-se também, em menor quantidade, o cultivo da laranja e de pastagens. Neste contexto o objetivo deste trabalho foi a caracterização de espécies químicas na deposição atmosférica total (DT) e deposição atmosférica apenas úmida (DU) da cidade de SJRP visando avaliar a contribuição da mesma como fonte destes compostos para o rio Preto. Um total de 103 amostras de DT e 96 de DU foram coletadas para o período de março de 2009 a setembro de 2010. A amostragem, preservação e quantificação de Al, Sb, As, Ba, Cd, Cu, Pb, Cr, Ni...

Mercury Concentrations in Bulk Atmospheric Deposition over the Coast of Rio de Janeiro, Southeast, Brazil

Lacerda,Luiz D.; Paraquetti,Heloisa Helena M.; Rezende,Carlos E.; Silva,Luiz Fernando F.; Silva Filho,Emanuel V.; Marins,Rozane V.; Ribeiro,Mario G.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2002 EN
Relevância na Pesquisa
86.21%
Total Hg concentrations were measured in bulk atmospheric deposition from three sampling stations along the Rio de Janeiro State coast, Southeast, Brazil, from October 1998 to December 1999. Samples were collected at Campos dos Goytacazes, an agriculture center at the North coast; Niterói, an industrialized metropolitan area and at Itacuruçá, a tourist town at the South. Concentrations at Campos average 0.51 ng L-1, ranging from 0.07 to 1.01 ng L-1, and showed a seasonal trend, probably affected by burning of sugar cane plantations in winter. At Niterói, concentrations were highest, averaging 0.73 ng L-1 andranging from 0.06 to 2.95 ng L-1. No pattern of temporal variation was observed and concentration peaks are probably related to industrial emissions. At Itacuruçá, Hg concentrations were below the detection limit of the method (0.02 ng L-1) in 35% of the samples, with an average of 0.24 ng L-1 and ranging from <0.02 to 1.04 ng L-1.

Determination of the Sampler Type and Rainfall Effect on the Deposition Fluxes of the Polychlorinated Biphenyls

Birgül, Askin; Tasdemir, Yücel
Fonte: The Scientific World Journal Publicador: The Scientific World Journal
Tipo: Artigo de Revista Científica
Publicado em 02/05/2012 EN
Relevância na Pesquisa
26.15%
Atmospheric concentration and deposition samples were collected between June 2008 and June 2009 in an urban sampling site Yavuzselim, Turkey. Eighty-three polychlorinated biphenyl (PCB) congeners were targeted in the collected samples. It was found that 90% of the total PCB concentration was in the gas phase. Deposition samples were collected by a wet-dry deposition sampler (WDDS) and a bulk deposition sampler (BDS). Average total deposition fluxes measured with the BDS in dry periods was 5500 ± 2400 pg/(m2day); average dry deposition fluxes measured by the WDDS in the same period were 6400 ± 3300 pg/(m2day). The results indicated that the sampler type affected the measured flux values. Bulk deposition samples were also collected in rainy periods by using the BDS and the average flux value was 8700 ± 3100 pg/(m2day). The measured flux values were lower than the values reported for the urban and industrial areas. Dry deposition velocities for the WDDS and BDS samples were calculated 0.48 ± 0.35 cm/s and 0.13 ± 0.15 cm/s, respectively.

Stable Carbon and Nitrogen Isotopes in a Peat Profile Are Influenced by Early Stage Diagenesis and Changes in Atmospheric CO2 and N Deposition

Esmeijer-Liu, Alice J.; Kürschner, Wolfram M.; Lotter, André F.; Verhoeven, Jos T. A.; Goslar, Tomasz
Fonte: Springer Netherlands Publicador: Springer Netherlands
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.4%
In this study, we test whether the δ13C and δ15N in a peat profile are, respectively, linked to the recent dilution of atmospheric δ13CO2 caused by increased fossil fuel combustion and changes in atmospheric δ15N deposition. We analysed bulk peat and Sphagnum fuscum branch C and N concentrations and bulk peat, S. fuscum branch and Andromeda polifolia leaf δ13C and δ15N from a 30-cm hummock-like peat profile from an Aapa mire in northern Finland. Statistically significant correlations were found between the dilution of atmospheric δ13CO2 and bulk peat δ13C, as well as between historically increasing wet N deposition and bulk peat δ15N. However, these correlations may be affected by early stage kinetic fractionation during decomposition and possibly other processes. We conclude that bulk peat stable carbon and nitrogen isotope ratios may reflect the dilution of atmospheric δ13CO2 and the changes in δ15N deposition, but probably also reflect the effects of early stage kinetic fractionation during diagenesis. This needs to be taken into account when interpreting palaeodata. There is a need for further studies of δ15N profiles in sufficiently old dated cores from sites with different rates of decomposition: These would facilitate more reliable separation of depositional δ15N from patterns caused by other processes.

Atmospheric Ionic Deposition in Tropical Sites of Central Sulawesi Determined by Ion Exchange Resin Collectors and Bulk Water Collector

Köhler, S.; Jungkunst, H. F.; Gutzler, C.; Herrera, R.; Gerold, G.
Fonte: Springer Netherlands Publicador: Springer Netherlands
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.3%
In the light of global change, the necessity to monitor atmospheric depositions that have relevant effects on ecosystems is ever increasing particularly for tropical sites. For this study, atmospheric ionic depositions were measured on tropical Central Sulawesi at remote sites with both a conventional bulk water collector system (BWS collector) and with a passive ion exchange resin collector system (IER collector). The principle of IER collector to fix all ionic depositions, i.e. anions and cations, has certain advantages referring to (1) post-deposition transformation processes, (2) low ionic concentrations and (3) low rainfall and associated particulate inputs, e.g. dust or sand. The ionic concentrations to be measured for BWS collectors may easily fall below detection limits under low deposition conditions which are common for tropical sites of low land use intensity. Additionally, BWS collections are not as independent from the amount of rain fallen as are IER collections. For this study, the significant differences between both collectors found for nearly all measured elements were partly correlated to the rainfall pattern, i.e. for calcium, magnesium, potassium and sodium. However, the significant differences were, in most cases...

Spatial distribution and seasonal variation of atmospheric bulk deposition of polycyclic aromatic hydrocarbons in Beijing–Tianjin region, North China

Wang, Wentao; Simonich, Staci L. Massey; Giri, Basant; Xue, Miao; Zhao, Jingyu; Chen, Shejun; Shen, Huizhong; Shen, Guofeng; Wang, Rong; Cao, Jun; Tao, Shu
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /01/2011 EN
Relevância na Pesquisa
26.15%
Bulk deposition samples were collected in remote, rural village and urban areas of Beijing–Tianjin region, North China in spring, summer, fall and winter from 2007 to 2008. The annually averaged PAHs concentration and deposition flux were 11.81 ± 4.61 µg/g and 5.2 ± 3.89 µg/m2/day respectively. PHE and FLA had the highest deposition flux, accounting for 35.3% and 20.7% of total deposition flux, respectively. More exposure risk from deposition existed in the fall for the local inhabitants. In addition, the PAHs deposition flux in rural villages (3.91 µg/m2/day) and urban areas (8.28 µg/m2/day) was 3.8 and 9.1 times higher than in background area (0.82 µg/m2/day), respectively. This spatial variation of deposition fluxes of PAHs was related to the PAHs emission sources, local population density and air concentration of PAHs, and the PAHs emission sources alone can explain 36%, 49%, 21% and 30% of the spatial variation in spring, summer, fall and winter, respectively.

Nitrogen Deposition Effects on Diatom Communities in Lakes from Three National Parks in Washington State

Sheibley, Richard W.; Enache, Mihaela; Swarzenski, Peter W.; Moran, Patrick W.; Foreman, James R.
Fonte: Springer International Publishing Publicador: Springer International Publishing
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.16%
The goal of this study was to document if lakes in National Parks in Washington have exceeded critical levels of nitrogen (N) deposition, as observed in other Western States. We measured atmospheric N deposition, lake water quality, and sediment diatoms at our study lakes. Water chemistry showed that our study lakes were ultra-oligotrophic with ammonia and nitrate concentrations often at or below detection limits with low specific conductance (<100 μS/cm), and acid neutralizing capacities (<400 μeq/L). Rates of summer bulk inorganic N deposition at all our sites ranged from 0.6 to 2.4 kg N ha−1 year−1 and were variable both within and across the parks. Diatom assemblages in a single sediment core from Hoh Lake (Olympic National Park) displayed a shift to increased relative abundances of Asterionella formosa and Fragilaria tenera beginning in the 1969–1975 timeframe, whereas these species were not found at the remaining (nine) sites. These diatom species are known to be indicative of N enrichment and were used to determine an empirical critical load of N deposition, or threshold level, where changes in diatom communities were observed at Hoh Lake. However, N deposition at the remaining nine lakes does not seem to exceed a critical load at this time. At Milk Lake...

Atmospheric pathways of chlorinated pesticides and natural bromoanisoles in the northern Baltic Sea and its catchment

Bidleman, Terry; Agosta, Kathleen; Andersson, Agneta; Brorström-Lundén, Eva; Haglund, Peter; Hansson, Katarina; Laudon, Hjalmar; Newton, Seth; Nygren, Olle; Ripszam, Matyas; Tysklind, Mats; Wiberg, Karin
Fonte: Springer Netherlands Publicador: Springer Netherlands
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.1%
Long-range atmospheric transport is a major pathway for delivering persistent organic pollutants to the oceans. Atmospheric deposition and volatilization of chlorinated pesticides and algae-produced bromoanisoles (BAs) were estimated for Bothnian Bay, northern Baltic Sea, based on air and water concentrations measured in 2011–2012. Pesticide fluxes were estimated using monthly air and water temperatures and assuming 4 months ice cover when no exchange occurs. Fluxes were predicted to increase by about 50 % under a 2069–2099 prediction scenario of higher temperatures and no ice. Total atmospheric loadings to Bothnian Bay and its catchment were derived from air–sea gas exchange and “bulk” (precipitation + dry particle) deposition, resulting in net gains of 53 and 46 kg year−1 for endosulfans and hexachlorocyclohexanes, respectively, and net loss of 10 kg year−1 for chlordanes. Volatilization of BAs releases bromine to the atmosphere and may limit their residence time in Bothnian Bay. This initial study provides baseline information for future investigations of climate change on biogeochemical cycles in the northern Baltic Sea and its catchment.

Towards an understanding of the carbon isotopic changes across the Toarcian oceanic anoxic event

Cohen, Alison Margaret
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 68 p.; 2427956 bytes; 2430699 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
36.29%
A combination of bulk carbon, biomarker and compound specific isotopic analyses were used in order to investigate the changes which accompanied the deposition of black shales during the upper tenuicostatum and lower falciferum zones of the Toarcian (early Jurassic, 183 Ma) ocean anoxic event (OAE). In this study, we reveal that apparent negative isotopic excursions in bulk organic and carbonate carbon were the result of compositional changes of organic matter and diagenesis, respectively. Organic petrology and Rock-Eval pyrolysis of organic matter from the Jet Rock, Hawsker Bottoms, Yorkshire, England, show that the upper tenuicostatum zone contains very large amounts of terrigenous debris. A careful review of the carbonate carbon record, as reported in the literature, indicates that a large negative isotopic excursion in bulk carbonate is likely the result of diagenesis, rather than reflective of seawater isotopic conditions. Biomarker distributions and isotopic composition of primary production biomarkers show little variation during the largest changes in the bulk records. Biomarker source indicators vary little throughout the section, indicating little change in biota or redox structure of the water column during this widespread deposition of black shales. Isotopic compositions of algal short chain n-alkanes...

Atmospheric Input of POPs into Lake Maggiore (Northern Italy): PCDD/Fs and Dioxin-like PCBs Profiles and Fluxes in the Atmosphere and Aquatic System

CASTRO JIMENEZ JAVIER; MARIANI GIULIO; EISENREICH STEVEN; CHRISTOPH EUGEN; HANKE GEORG; CANUTI Elisabetta; SKEJO HELLE; UMLAUF GUNTHER
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Articles in Journals Formato: Printed
ENG
Relevância na Pesquisa
36.36%
The delivery and accumulation of PCDD/Fs and dioxin-like PCBs (DL-PCBs) as recorded in sediments from the Lake Maggiore (LM) in Northern Italy and the influence of the atmosphere in contaminating this subalpine ecosystem was studied. PCDD/Fs (17 congeners) and DL-PCBs (12 congeners) concentrations, congener profiles and fluxes in air, bulk deposition, aquatic settling material and surface sediments are presented in this work. Our strategy was to obtain surface sediment from areas near riverine inputs and in the depositional basins, settling material in sediment traps at one site and air, aerosol and bulk deposition profiles. Concentrations in air of 24.5 WHO-TEQ fg m-3 PCDD/Fs and 6.8 WHO-TEQ fg m-3 DL-PCBs were obtained. Bulk deposition of 136.6 and 28.5 WHO-TEQ pg m-2 for dioxins/furans and DL-PCBs respectively, resulted during one sampled week. Aquatic settling material had a concentration of 11.4 WHO-TEQ pg g-1 for PCDD/Fs and a concentration of 2.3 WHO-TEQ pg g-1 for DL-PCBs. PCDD/Fs concentrations in surface sediments varied from 0.13 to 16.9 WHO-TEQ pg g-1whereas values ranged from 0.03 to 4.7 WHO-TEQ pg g-1 for DL-PCBs. The concentrations obtained in the environmental compartments studied suggest a situation of low level contamination. Similarity in PCDD/Fs and DL-PCBs congeners profiles in atmospheric air...

Occurrence of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans (PCDD/Fs), Polychlorinated Biphenyls (PCBs) and Polybrominated Diphenyl Ethers (PBDEs) in Lake Maggiore (Italy and Switzerland)

VIVES RUBIO INGRID; CANUTI ELISABETTA; CASTRO JIMENEZ JAVIER; CHRISTOPH EUGEN; EISENREICH STEVEN; HANKE GEORG; HUBER TANIA; MARIANI GIULIO; MUELLER ANNE; SKEJO HELLE; UMLAUF GUNTHER; WOLLGAST JAN
Fonte: ROYAL SOC CHEMISTRY Publicador: ROYAL SOC CHEMISTRY
Tipo: Articles in Journals Formato: Printed
ENG
Relevância na Pesquisa
26.19%
Samples of air (gas and particulate phases), bulk deposition, aquatic settling material and sediments were collected in Lake Maggiore (LM) in order to determine their content of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Air (gas and particulate phases) concentrations were 0.5 pg m-3, 80 pg m-3, 13 pg m-3 and 106 pg m-3 for sum PCDD/Fs, sum PCBs, sum dioxin like-PCBs (DL-PCBs) and sum PBDEs, respectively. Deposition fluxes ranged from 0.7 ng m-2 day-1 for sum PCDD/Fs to 32 ng m-2 day-1 for sum PCBs. Aquatic settling material presented concentrations of 0.4 ng g-1 dw for sum PCDD/Fs, 13 ng g-1 dw for sum PCB, 3.4 ng g-1 dw for sum DL-PCBs and 5.7 ng g-1 dw for sum PBDEs. Mean sediment samples concentration were 0.4 ng g-1 dw for sum PCDD/Fs, 11 ng g-1 dw for sum PCB, 3 ng g-1 dw for sum DL-PCBs and 5.1 ng g-1 dw for sum PBDEs. Similar PCDD/F and DL-PCB congener patterns in all the environmental compartments of LM point to an important, if not dominant, contribution of atmospheric deposition as source of these pollutants into LM. In contrast, BDE congener distribution was not similar in the different environmental compartments. BDE 47 dominated air samples and settling material...

Bulk Atmospheric Deposition of Major Ions and Dissolved Organic Nitrogen in the Lower Course of a Tropical River Basin, Southern Bahia, Brazil

Araujo,Taiana G.; Souza,Marcelo F. L.; Mello,William Z. de; Silva,Daniela M. L. da
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2015 EN
Relevância na Pesquisa
45.91%

Conception of the Mercury Deposition Coefficient Based on Long-term Stream Intensity Measurements of Mercury Species TGM and TPM

Nowak, Bartosz; Czaplicka, Marianna
Fonte: Springer International Publishing Publicador: Springer International Publishing
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.15%
For many years, atmospheric mercury has been perceived as a global pollutant. Transport of mercury compounds in the atmosphere and its deposition on the earth’s surface is an important issue that requires knowledge regarding the circulation of the various forms of this metal between environmental components. There are many numerical models that can be used to study and image this phenomenon. These models are based on data concerning mercury emission sources, concentrations of this contaminant on modelling areas and meteorological data to assess air mass inflow on a regional and global scale. A method to assess mercury deposition fluxes on a local scale based only on stream intensity analysis of mercury is proposed in this study. Mercury deposition fluxes (bulk) that were assessed by the MDC method at the Zloty Potok station (regional background station for the Silesian Agglomeration) varied from 22.8 μg · m−2 · year−1 (an 8-month period in 2013) to 54.2 μg · m−2 · year−1 in 2012. Developing procedures to estimate the mercury deposition coefficient (MDC) is useful in areas where only meteorological parameters and mercury concentrations in the atmospheric air are measured. The obtained deposition coefficient values enable quantification of a selected pollutant concentration and its potential impact resulting from deposition.

Factors governing the atmospheric deposition of polycyclic aromatic hydrocarbons to remote areas

Fernández Ramón, M. Pilar; Carrera, Guillem; Grimalt, Joan O.; Ventura, Marc; Camarero, Lluís; Catalán, Jordi; Nickus, Ulrike; Thies, Hansjörg; Psenner, Roland
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artículo Formato: 22195 bytes; application/pdf
ENG
Relevância na Pesquisa
76.43%
7 pages, 4 figures, 1 table.-- PMID: 12966968 [PubMed].-- Printed version published 1 Aug, 2003.; Polycyclic aromatic hydrocarbons (PAH) were measured in bulk atmospheric deposition collected in three remote areas of Europe during 1997−1998. Mean total PAH fluxes over a period of 18 months were 1560 ± 750 and 1150 ± 630 ng m-2 mo-1 in the Pyrenees and the Alps, respectively. In the Caledonian mountains (Scandinavia) the observed mean fluxes were 1900 ± 940 ng m-2 mo-1 (6 month collection). Similar qualitative PAH compositions (p values <0.05) in the bulk atmospheric deposition have been observed between sites, which are dominated by the more volatile parent compounds. The main differences between lakes are related to the high molecular weight compounds. Atmospheric deposition of PAH to these remote sites appears to be independent of their concentrations in the atmosphere, which are similar between sites (in the range of 1.8−3.0 ng·m-3), being controlled mainly by particle deposition, followed by precipitation and air temperature. A multilevel regression model including these three variables accounted for 74% of the total variability in total PAH bulk deposition; however, the contribution of each variable in the model is compound and site-dependent. The deposition of high molecular weight PAH depends more on particle deposition and precipitation...

Atmospheric chloride deposition in continental Spain

Alcalá, Francisco J.; Custodio, Emilio
Fonte: John Wiley & Sons Publicador: John Wiley & Sons
Tipo: Artículo Formato: 453895 bytes; application/pdf
ENG
Relevância na Pesquisa
66.49%
15 pages, 9 figures.; The atmospheric bulk deposition rate of chloride in continental Spain was studied to get basic information in order to help in the evaluation of diffuse recharge to aquifers through an environmental chemical balance. Both new, recent data and bibliographic data have been used. Most sampling records are less than 5 years long and often only 1 year long. This means that the calculated mean yearly bulk deposition rate of chloride is quite uncertain by 30% on average, and larger than the values derived form records up to 15 years long. A map of atmospheric bulk deposition of chloride has been drawn using ordinary kriging. The mean bulk deposition rate of chloride varies from 1 to 30 g m-2 year-1 in coastal areas, with strong negative landward gradients between 0·1 and 1 g m-2 year-1 km-1. In the centre of the Iberian Peninsula, chloride deposition rates vary from 0·2 to 0·5 g m-2 year-1, with gradients around or less than 5 × 10-3 g m-2 year-1 km-1. The coefficient of variation of the mean bulk atmospheric deposition rate of chloride, for any place, ranges from 0·1 to 1. Values larger than 0·5 are not a good indicator of natural uncertainty for this series of data that has a skewed distribution. The map of bulk deposition rate and its error is one of the terms needed for aquifer recharge estimation by means of the chloride ion balance.; We would like to thank the endowment of the Spanish Research Project HID1999-0205. The first author is also grateful to the Ministry of Education and Science of Spain for a ‘Juan de la Cierva’ Programme Contract (reference JCI-2007-334).; Peer reviewed

Red rains as major contributors of nutrients and alkalinity to terrestrial ecosystems at Montseny (NE Spain)

Àvila i Castells, Anna; Rodà, Ferran
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //1991 ENG
Relevância na Pesquisa
36%
During two years (1983-1985), 8 red rains were collected in the Montseny mountains. The suspended matter contained in red rains has its source in the Sahara desert and corresponds to fine silts. Due to the calcite content of dust responsible for the red rains, these rains are alkaline with a volume weighted mean pH of 7.7 versus 4.7 of non-red rains. Estimated HCO; alkalinity input due to red rains is 0.21 keqlhalyr and total annual HCO; alkalinity input is 0.24 keqlhalyr. To that figure, one has to add at least 0.24 keqlhalyr due to the alkalinity of calcite contained in red dust. For the same period, hydrogen input in bulk deposition amounts to 0.19 keqlhalyr. These results indicate that acidity due to non-red rain espisodes is neutralized on an annual basis, with red rains being the major neutralizing agent. Ion concentrations in red rains are high, which makes them an important source of nutrients even though they only account for 5.4% of annual preci itation. Red rains are particularly enriched with ca2+ having a P+ volume-weighted mean Ca concentration 14 times higher than non-red rains and delivering 46% of the annual inputs of soluble ca2+ in bulk precipitation at Montseny.; Durant dos anys (1983-1985) es varen recollir 8 pluges de fang a La Castanya (Montseny). La matèria particulada de les pluges de fang s'origina al desert del Sahara...

Increasing and decreasing trends of the atmospheric deposition of organochlorine compounds in European remote areas during the last decade

Arellano, L.; Fernández, P.; Fonts Beuter, Roger; Rose, N. L.; Nickus, U.; Thies, H.; Stuchlík, E.; Camarero, Lluís; Catalan, Jordi; Grimalt Obrador, Joan
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //2015 ENG
Relevância na Pesquisa
76.26%
Bulk atmospheric deposition samples were collected between 2004 and 2007 at four high-altitude European sites encompassing east (Skalnaté Pleso), west (Lochnagar), central (Gossenköllesee) and south (Redòn) regions, and analysed for legacy and current-use organochlorine compounds (OCs). Polychlorobiphenyls (PCBs) generally showed the highest deposition fluxes in the four sites, between 112 and 488 ng m¯² mo¯¹, and hexachlorobenzene (HCB) the lowest, a few ng m¯² mo¯¹. Among pesticides, endosulfans were found at higher deposition fluxes (11–177 ng m¯² mo¯¹) than hexachlorocyclohexanes (HCHs) (17–66 ng m¯² mo¯¹) in all sites except Lochnagar that was characterized by very low fluxes of this insecticide. Comparison of the present measurements with previous determinations in Redòn (1997–1998 and 2001–2002) and Gossenköllesee (1996–1998) provided for the first time an assessment of the long-term temporal trends in OC atmospheric deposition in the European background areas. PCBs showed increasing deposition trends while HCB deposition fluxes remained nearly constant. Re-emission of PCBs from soils or as a consequence of glacier melting and subsequent precipitation and trapping of the volatilized compounds may explain the observed PCB trends. This process does not occur for HCB due to its high volatility which keeps most of this pollutant in the gas phase. A significant decline of pesticide deposition was observed during this studied decade (1996–2006) which is consistent with the restriction in the use of these compounds in most of the European countries. In any case...

Source areas and atmospheric transport processes of chemical compounds and pollen in the NE Iberian Peninsula and the Canary Islands

Izquierdo Miguel, Rebeca
Fonte: [Barcelona] : Universitat Autònoma de Barcelona, Publicador: [Barcelona] : Universitat Autònoma de Barcelona,
Tipo: Tesis i dissertacions electròniques; info:eu-repo/semantics/doctoralThesis Formato: application/pdf
Publicado em //2012 ENG; ENG
Relevância na Pesquisa
36.44%
Els ecosistemes forestals reben una entrada important de nutrients per deposició atmosfèrica. Per conèixer millor els mecanismes de deposició s'han realitzat mesures en paral·lel de la deposició humida, seca i global en una estació de mostreig al Montseny. La comparació entre els fluxos humit i sec va revelar que els compostos atmosfèrics en aquesta zona es dipositen principalment via deposició humida (74% de deposició humida+seca). Els nostres resultats indiquen que la deposició global representa bé la deposició atmosfèrica total, ja que la deposició global més les partícules dipositades després de l'última pluja van representar el 97% de la deposició total (humida+seca). Els models de canvi climàtic per a la regió Mediterrània prediuen modificacions en els patrons de circulació de vent i de precipitació. La caracterització de la climatologia sinòptica i el transport a llarga distància de contaminants atmosfèrics al Montseny va mostrar una disminució de les adveccions atlàntiques i un augment de les masses d'aire africanes i europees en la circulació general en del NE d'Espanya. S'han aplicat Mètodes d'Anàlisi Estadístic de Trajectòries (TSMs) per interpretar els canvis de la química de la precipitació durant els últims 25 anys en alguns ions que mostren tendències significatives (ex. SO42-...

Hidrocarburos aromáticos policíclicos (HAPS) en la fracción soluble de la deposición atmosférica en Cantabria : análisis de sus niveles y estudio preliminar de su origen; Polycyclic aromatic hydrocarbons (PAHs) in the soluble fraction of the atmospheric deposition in Cantabria : analysis of their levels and preliminary study on their origin

Laita Bezanilla, Carmen
Fonte: Universidade de Cantabria Publicador: Universidade de Cantabria
Tipo: Trabalho de Conclusão de Curso
SPA
Relevância na Pesquisa
56.01%
Grado en Ingeniería Química