Aliphatic and aromatic hydrocarbons in tropical recent sediments of Campos dos Goytacazes, RJ, Brazil

Journal of the Brazilian Chemical Society

Alexandre De O. Gomes¹  Débora De A. Azevedo¹ 

[1] ,Universidade Federal do Rio de Janeiro Instituto de Química Rio de Janeiro RJ ,Brazil

关键词: hydrocarbons;    sediments;    PAH;    isoprenoid;    (C/N) ratios;    organic matter;   

DOI  :  10.1590/S0103-50532003000300004

来源: SciELO

【 摘 要 】

Sediment samples from the Imbé, the Urubu and the Ururaí rivers and from Lake de Cima were studied. These sites are located in the county of Campos dos Goytacazes, Rio de Janeiro, Brazil. Aliphatic and aromatic fractions were analyzed by GC-FID and GC-MS in order to gather information on the degree of contamination by anthropogenic activities and other biogenic contributions. Concentrations of total aliphatic and aromatic hydrocarbons were 1.2, 2.8, 5.8 and 4.3 mug g-1 and 74, 30, 722 and 340 ng g-1 in the Imbé, Ururaí, Urubu rivers and Lake de Cima, respectively. The C20 highly branched isoprenoid alkane was identified in the Urubu sediment. There were no hopanes or steranes in any sample. Anthropogenic aromatic compounds, detected at trace levels, were observed only in the Imbé and in Lake de Cima (227 ng g-1). The fluoranthene/pyrene rate for Lake de Cima was 4.2, suggesting a combustion origin for the PAH. This data is consistent with the frequently sugar cane burning practice that occurs in this region. A greater input from higher plants was observed in the Urubu, Imbé and Lake de Cima sediments; on the other hand, the aquatic input predominates for Ururaí. In summary, Lake de Cima sediment is considered very slightly polluted, while the others are unpolluted.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License