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Previous issue date: 2011-02-07 / Estuaries are environments prone to the input of chemical pollutants of various kinds
and origins, including polycyclic aromatic hydrocarbons (PAHs). Anthropogenic PAHs
may have two possible sources: pyrolytic (with four or more aromatic rings and low
degree of alkylation) and petrogenic (with two and three aromatic rings and high degree
of alkylation). This study aimed to evaluate the levels, distribution and possible sources
of polycyclic aromatic hydrocarbons in the estuary of the Potengi river, Natal, Brazil.
Samples of bottom sediments were collected in the final 12 km of the estuary until its
mouth to the sea, where the urbanization of the Great Natal is more concentrated.
Sampling was performed on 12 cross sections, with three stations each, totaling 36
samples, identified as T1 to T36. The non alkylated and alkylated PAHs were analyzed
by gas chromatography coupled to mass spectrometry (GC / MS). PAHs were detected
in all 36 stations with total concentration on each varying 174-109407 ng g-1. These
values are comparable to those of several estuarine regions worldwide with high
anthropogenic influence, suggesting the record of diffuse contamination installed in the
estuary. PAHs profiles were similar for most stations. In 32 of the 36 stations, low
molecular weight PAHs (with 2 and 3 ring: naphthalene, phenanthrene and their
alkylated homologues) prevailed, which ranged from 54% to 100% of the total PAH,
indicating that leaks, spills and combustion fuels are the dominant source of PAH
pollution in the estuary. The level of contamination by PAHs in most stations suggests
that there is potential risk of occasional adverse biological effects, but in some stations
adverse impacts on the biota may occur frequently. The diagnostic ratios could
differentiate sources of PAHs in sediments of the estuary, which were divided into three
groups: petrogenic, pyrolytic and mixing of sources. The urban concentration of the
Great Natal and the various industrial activities associated with it can be blamed as
potential sources of PAHs in bottom sediments of the estuary studied. The data
presented highlight the need to control the causes of existing pollution in the estuary / Os estu?rios s?o ambientes prop?cios ao aporte de poluentes qu?micos de diversas
naturezas e origens, incluindo Hidrocarbonetos Polic?clicos Arom?ticos (HPA). Os
HPA antr?picos s?o de duas fontes poss?veis: pirol?tica (com quatro ou mais an?is
arom?ticos e baixo grau de alquila??o) e petrog?nica (com dois e tr?s an?is arom?ticos e
alto grau de alquila??o). O presente trabalho teve como objetivo avaliar os n?veis,
distribui??o e poss?veis fontes de Hidrocarbonetos Polic?clicos Arom?ticos no estu?rio
do rio Potengi, Natal-RN. Amostras de sedimentos de fundo foram coletadas nos 12 km
finais do estu?rio at? a sua foz, onde a urbaniza??o da Grande Natal ? mais concentrada.
A amostragem foi realizada em 12 se??es transversais, com tr?s esta??es em cada uma,
totalizando 36 amostras, identificadas de T1 a T36. Os HPA alquilados e n?o alquilados
foram analisados por cromatografia gasosa acoplada a um detector seletivo de massas
(CG/EM). Foram detectados HPA em todas as 36 esta??es, com concentra??o total em
cada uma variando de 174 a 109407 ng g-1. Esses valores s?o compar?veis aos de v?rias
regi?es estuarinas mundiais com grande influ?ncia antr?pica, o que sugere o registro de
contamina??es difusas instaladas no estu?rio. O perfil de HPA foi similar para a maioria
das esta??es. Em 32 das 36 esta??es predominaram HPA de baixo peso molecular (com
2 e 3 an?is: naftaleno, fenantreno e seus hom?logos alquilados), que variaram de 54% a
100% em rela??o ao total de HPA, indicando que vazamentos, derramamentos e queima
de combust?veis s?o a fonte dominante de polui??o por HPA no estu?rio. O n?vel de
contamina??o por HPA na maioria das esta??es sugere que h? risco potencial de
ocasionais efeitos biol?gicos adversos serem observados, por?m em algumas esta??es se
confirmam que impactos adversos sobre a biota ocorrem com freq??ncia. As raz?es
diagn?sticas permitiram diferenciar as fontes de HPA nos sedimentos do estu?rio, que
foram divididos em tr?s grupos: sedimentos com padr?es de introdu??o de
hidrocarbonetos petrog?nicos, pirol?ticos e de mistura de fontes. A concentra??o urbana
da Grande Natal e as atividades industriais diversas a ela associadas podem ser
responsabilizadas como fontes potenciais dos HPA nos sedimentos de fundo do estu?rio
estudado. Os dados apresentados evidenciam a necessidade de se controlar as causas da
polui??o existente no estu?rio
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/12937 |
| Date | 07 February 2011 |
| Creators | Queiroz, Maria Sara Maia de |
| Contributors | CPF:08036691434, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4781194Y6, Dantas, Tereza Neuma de Castro, CPF:07286937391, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783139Z0&dataRevisao=null, Mendes, Franklin Silva, CPF:03361848750, http://lattes.cnpq.br/0948550631285518, Melo J?nior, Germano |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Ci?ncia e Engenharia do Petr?leo, UFRN, BR, Pesquisa e Desenvolvimento em Ci?ncia e Engenharia de Petr?leo |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | Portuguese |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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