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Assinaturas antropog?nicas de elementos maiores e tra?os em poeira urbana na cidade do Natal-RN

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Previous issue date: 2011-03-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Although there are many studies on urban dust contamination by heavy metals in
developed countries, little attention has been paid to this type of study in developing
countries, including Brazil. Therefore, a series of investigations were performed to provide
signatures of heavy metals in urban dust and assess the potential sources in the city of Natal -
RN-Brazil. The fraction of these sediments was studied to pass through a sieve of 63
micrometers. For the study analyzed two groups of samples, one collected in September 2009
at the end of the rainy season (9 samples) and one collected in January 2010 in the dry season
(21 samples). So in all, thirty sediment samples were collected from the street. Then, in
Fluorescence Spectrometry X-rays were determined major elements SiO2, Na2O, K2O, Al2O3,
MgO, P2O5, Fe2O3, MnO, TiO2 and CaO, and trace Rb, Cr, Ni, Cu, Zn, Sr and Pb by an ICPOES
was determined Zn, V, Na, K, Ni, Mn, Mg, P, Fe, Cr, Cu, Pb, Ba, Ca and Al from
leaching HCl 0.5 mol L-1 . The results of the concentrations of elements show that the greater
presence of these occurs in the dry season, except for Si which is higher in the rainy season.
Analyses by geoaccumulation Index (IGEO) Enrichment Factor (EF), Contamination Factor
(CF), analysis correlation and Hierarchical Cluster, confirm that Zn, Cu and Pb is
anthropogenic character. Zinc may be derived from various sources related to motor vehicles
or the road signs and street grids. The elements Na, K, Mg and Ca may be related to droplets
suspended in air containing cations and anions present in seawater (salty), common in
Christmas throughout the year, brought by winds SE-NW. The elements Na, Mg, Ca and K
are the most abundant in seawater and were analyzed in this study. This indicates that the
source of these additional elements detected by analyzing the contamination factor may be the
very sea. Moreover, Ni, Fe, Cr and Ba can be either as a source of anthropogenic geog?nica.
The source of Ca is different, because it comes in lime and paint (painting guides of buildings
and streets) in construction materials, but may also be present in sediments in the fragments of
shells or carbonate bioclasts common in the coastal area / Embora existam muitos estudos sobre a contamina??o de poeiras urbanas por metais
pesados nos pa?ses desenvolvidos, pouca aten??o tem sido dada a este tipo de estudo nos
pa?ses em desenvolvimento, incluindo o Brasil. Portanto, uma s?rie de investiga??es foram
realizadas para fornecer assinaturas de metais pesados em poeiras urbanas e avaliar as fontes
potenciais na cidade do Natal RN-Brasil. A fra??o estudada destes sedimentos foi a passante
na peneira de 63 μm. Para o estudo foram analisados dois grupos de amostras, sendo um
coletado no m?s de setembro de 2009 no final da esta??o chuvosa (9 amostras) e outro
coletado no m?s de janeiro de 2010 no final da esta??o seca (21 amostras). Portanto ao todo,
trinta amostras de sedimentos de rua foram coletadas. Em seguida, por Espectrometria de
Fluoresc?ncia de raios X foram determinados os elementos maiores SiO2, Na2O, K2O, Al2O3,
MgO, P2O5, Fe2O3, MnO, TiO2 e CaO e tra?os Rb, Cr, Ni, Cu, Zn, Sr e Pb. Pela t?cnica de
ICP-OES foram determinados Zn, V, Na, K, Ni, Mn, Mg, P, Fe, Cr, Cu, Pb, Ca, Ba e Al a
partir de lixivia??o a HCl 0,5 mol L-1. Os resultados das concentra??es dos elementos
mostram que a maior presen?a desses ocorre na esta??o seca, com exce??o para o Si que ?
maior na esta??o chuvosa. As an?lises por ?ndice de Geoacumula??o (IGeo), Fator de
Enriquecimento (FE), Fator de Contamina??o (FC), an?lises de correla??o e agrupamentos,
confirmam que Zn, Cu e Pb tem car?ter antropog?nico. O Zn pode ser proveniente de fontes
diversas relacionados aos ve?culos automotores ou ?s placas de sinaliza??o e grades das ruas.
Os elementos Na, K, Mg e Ca podem estar relacionados ?s got?culas de ar que cont?m em
suspens?o os c?tions e ?nions presentes na ?gua do mar (maresia), comum em Natal durante
todo o ano, trazida pelos ventos SE-NW. Os elementos Na, Mg, Ca e K s?o os mais
abundantes na ?gua do mar e foram analisados no presente trabalho. Isto indica que a fonte
adicional destes elementos detectada atrav?s da an?lise do fator de contamina??o pode ser a
pr?pria maresia. Por outro lado, Ni, Fe, Cr e Ba podem ser tanto de origem antropog?nica
como de origem geog?nica. A fonte do Ca ? diversa, pois este entra na cal e tintas (pintura de
edifica??es e guias de ruas), nos materiais de constru??o civil, mas pode estar tamb?m
presente nos sedimentos nos fragmentos de conchas ou bioclastos carbon?ticos comuns na
?rea litor?nea

Identiferoai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17705
Date11 March 2011
CreatorsAzevedo Filho, Jo?o Batista de
ContributorsCPF:35530502415, http://lattes.cnpq.br/9770622597949866, Melo, Jailson Vieira de, CPF:50073788449, http://lattes.cnpq.br/7275955550556570, Lima, K?ssio Michell Gomes de, CPF:03144855464, http://lattes.cnpq.br/6928918856031880, Lima, Raquel Franco de Souza, CPF:24043427204, http://lattes.cnpq.br/5181465668193577, Borges, Lucila Ester Prado, CPF:35262699472, http://lattes.cnpq.br/9065968886119578, Ara?jo, Ant?nio Souza de
PublisherUniversidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Qu?mica, UFRN, BR, F?sico-Qu?mica; Qu?mica
Source SetsIBICT Brazilian ETDs
LanguagePortuguese
Detected LanguageEnglish
Typeinfo:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis
Formatapplication/pdf
Sourcereponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN
Rightsinfo:eu-repo/semantics/openAccess

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