Silva, Thais R., Lopes, Silvia R.P., Spörl, Gertrud, Knoppers, Bastiaan A. and Azevedo, Débora A. (2012) Source characterization using molecular distribution and stable carbon isotopic composition of n-alkanes in sediment cores from the tropical Mundaú–Manguaba estuarine–lagoon system, Brazil. Organic Geochemistry, 53 . pp. 25-33. DOI https://doi.org/10.1016/j.orggeochem.2012.05.009.

Text Spörl.pdf - Published Version Restricted to Registered users only Download (1MB)

Abstract

The Mundaú–Manguaba estuarine–lagoon system (MMELS) constitutes one of the most representative ecosystems in the state of Alagoas, NE Brazil. Approximately 30% or 60,000 ha of the lower surrounding drainage basin of the MMELS are covered by sugar cane and a total of 250,000 inhabitants contribute untreated effluent to the system. Short sediment cores from MMELS were collected in 2007 at three sites: Manguaba Lagoon (C03), Mundaú Lagoon (C07) and Mundaú River (C08) in order to characterize the delivery and deposition of n-alkanes over the past 40 yr. The n-alkanes ranged from C15 to C35, with total aliphatic hydrocarbon (TAH) concentration in the range 27.8–139.5 μg g−1. An unresolved complex mixture (UCM) was observed in all sediments. The terrigenous/aquatic ratio (TAR), carbon preference index (CPI) and average chain length (ACL) showed that the terrigenous input dominated. The (δ13C) values of individual n-alkanes (C16–C33) varied between −22.6‰ and −34.2‰, suggesting a dominance of 12C-enriched n-alkanes that originated from C3 plants and lacustrine algae. The data reflect how anthropogenic input (via sewage, industrial pollution and agriculture) has influenced the organic content of the system through time.

Document Type:	Article
Programme Area:	PA Not Applicable
Research affiliation:
Refereed:	Yes
Open Access Journal?:	No
DOI:	https://doi.org/10.1016/j.orggeochem.2012.05.009
ISSN:	01466380
Date Deposited:	22 Oct 2025 15:23
Last Modified:	22 Oct 2025 15:23
URI:	https://cris.leibniz-zmt.de/id/eprint/5851

Actions (login required)

View Item