Hydrocarbons in sediments of a chronically contaminated bay: The challenge of source assignment

Wagener, Ângela de Luca Rebello; Meniconi, Maria de Fátima Guadalupe; Hamacher, Claudia; Farias, Cassia O.; Silva, Gilson C. da; Gabardo, Irene Terezinha; Scofield, Arthur de L.

doi:10.1016/j.marpolbul.2011.11.018

Cited by 63 publications

(41 citation statements)

References 22 publications

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“…Significantly higher concentrations of UCM were found by Wagener et al 30 near the station P2, which may indicate heterogeneity of the bay sediments that can be explained by the action of the tides in the remobilization and transport or even by dredging activities and sediment transport to outside the bay.…”

Section: Aliphatic Hydrocarbonsmentioning

confidence: 69%

“…39,40 It is considered one of the most degraded ecosystems of the Brazilian coast. 41 Several studies conducted in Guanabara Bay show environmental impacts such as eutrophication, 42,43 high sedimentation rates, 44,45 high concentrations of metals, [46][47][48][49][50][51] and hydrocarbons 25,27,30,52,53 in water, sediment and biota. Among the main sources of pollution to the bay, stand out more than 14,000 industries, domestic sewage discharges with low or no treatment, 14 oil terminals, 2 harbors, 32 boatyards and more than 1000 gas stations.…”

Section: Study Area and Samplingmentioning

confidence: 99%

“…Because of these conditions, sediments from the bay commonly show a high content of UCM due to the presence of degraded oil, especially near the harbor. 27,30 Compounds in the UCM interferes with the determination of the δ 13 C of n-alkanes, therefore, it is necessary to perform an effective clean-up of the extract. The clean-up must remove the branched and cyclic compounds that compose the UCM fraction and/or coelute with the peaks of interest in the chromatogram, without any losses in the analytical quality of minor compounds or isotopic fractionation during the separation process.…”

Section: Introductionmentioning

confidence: 99%

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Compound-Specific δ13C of n-Alkanes: Clean-Up Methods Appraisal and Application to Recent Sediments of a Highly Contaminated Bay

Ceccopieri

Scofield

Almeida

et al. 2018

J. Braz. Chem. Soc.

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Different clean-up methods to determine isotopic composition of n-alkanes were tested. Sources of organic matter in Guanabara Bay were re-examined through the δ 13 C of individual n-alkanes in surface sediment samples. The n-alkanes were efficiently isolated without significant losses of the compounds of interest. The δ 13 C of n-alkanes (n-C 17 to n-C 35 ) ranged between -34.0 and -26.4‰. More depleted δ 13 C values associated to higher carbon preference index (CPI > 4) suggest prevalence of biogenic n-alkanes from terrestrial origin in the inner stations influenced by inputs from mangrove areas. Small isotopic differences between odd and even-numbered chains and 13 C-enrichment in long-chain homologues indicate a petrogenic hydrocarbons contribution. Higher concentrations of short-chain compounds associated to a more 13 C-enriched total organic carbon (TOC) were found near the most intense sewage discharges. Results show that δ 13 C of n-alkanes can be applied to a highly degraded system as the Guanabara Bay and help improve the characterization of the organic matter. Keywords: GC-C-IRMS, UCM, urea adduction, organic matter, Guanabara Bay IntroductionThe composition and distribution of hydrocarbons in sediment samples provide information about the organic matter sources and transformation processes occurring in the environment. 1 Studies on n-alkanes have often been conducted to assess the origin of hydrocarbons, such as biogenic (marine or terrestrial) or petrogenic, found in the marine environment. The assessment makes use of the difference in the n-alkane chain length to draw conclusions on the sources of organic matter. In higher plants, for example, n-alkanes from epicuticular waxes show long chains and an odd over even-numbered carbon chain predominance. 2 Algae are characterized by shorter chain lengths with no expressive odd-over-even preference. 3 In contrast, n-alkanes in fossil fuels have a wide composition range, without predominance of odd or even-numbered chains. 4 However, despite these typical fingerprints, there are cases in which n-alkane profile of different classes of organisms overlap, resulting in ambiguous interpretations of the organic material sources. 5 Given this multiplicity of origins, an interpretation of the different sources exclusively by the concentrations of n-alkanes is very limited in more complex environments. 6 During the last decades, the carbon isotopic analysis of some biomarkers have been widely used as a valuable tool to better distinguish the sources of organic matter in marine environments. 5,[7][8][9][10][11][12][13][14] The carbon isotope composition in the biosynthesized organic material depends on both the isotopic composition of the carbon source used by organisms and the isotope discrimination that occurs during carbon fixation, which includes the steps of absorption and intracellular diffusion, and also the biosynthesis of the cell components. 15 Thus, when two classes of organisms present an overlap in the n-alkane distribution, additional information can b...

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Section: Aliphatic Hydrocarbonsmentioning

confidence: 69%

Section: Study Area and Samplingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Compound-Specific δ13C of n-Alkanes: Clean-Up Methods Appraisal and Application to Recent Sediments of a Highly Contaminated Bay

Ceccopieri

Scofield

Almeida

et al. 2018

J. Braz. Chem. Soc.

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“…As previously proposed by Mille et al (2007), the NAR was used to roughly estimate the proportions of natural and petroleum n-alkanes. Values from 0.3 to 0.6 were observed, indicating biogenic sources such as higher terrestrial plants or marine plants, rather than the zero values displayed by petroleum hydrocarbons and crude oils (Kanzari et al 2012;Wagener et al 2012). Another index used to discriminate terrestrial from marine inputs is the TAR (Bourbonniere and Meyers 1996), the ratio of longchain odd-numbered n-alkanes (nC 27 ?…”

Section: Resultsmentioning

confidence: 99%

Indicators of terrestrial biogenic hydrocarbon contamination and linear alkyl benzenes as land-base pollution tracers in marine sediments

Syakti

Asia

Kanzari

et al. 2013

Int. J. Environ. Sci. Technol.

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Aliphatics (n-alkanes) and polycyclic aromatic hydrocarbons (PAHs) were measured in surface sediments collected from 12 sampling points (P1-P12) of sewage discharge to the sea from the wastewater treatment plant of Cortiou (France). Total n-alkanes and PAHs concentrations ranged from 34 to 2,155 and 696 to 10,700 lg kg -1 , respectively. Some specific hydrocarbon indexes suggested that terrestrial biogenic inputs are predominant compared to marine sources and that pyrolytic sources derived from wood and biomass combustion contribute to PAHs in the surface sediments. Total linear alkyl benzenes in Cortiou sediments ranged from 42.9 to 502.3 lg kg -1 . Low internal and external (I/E) isomers ratio (P0) suggests that inadequately treated sewage is discharged into the marine environment while some environmental processes might change I/E ratios during transport seaward (P1-P12). The high contaminant levels followed by the cumulative concentration of several compounds may lead to elevated toxicity levels in the sediments.

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“…By comparing the results of several studies, we proposed in this study a value of 5000 ng/g for non-contaminated sediments, 5000-50,000 ng/g for urbanised sediments, and a value exceeding 50,000 ng/g for petroleum-contaminated sediments Wagener et al, 2012;Syakti et al, 2012). Table 1 shows that the ∑ n-alkanes were 353 and 435.3 ng/g for O1 and O2, respectively.…”

Section: Sediment Quality Significancementioning

confidence: 92%

Characterisation of the dynamics of organic contaminants ( n -alkanes, PAHs and PCBs) in a coastal area

Syakti

Oursel

Garnier

et al. 2017

Marine Pollution Bulletin

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Hydrocarbons in sediments of a chronically contaminated bay: The challenge of source assignment

Cited by 63 publications

References 22 publications

Compound-Specific δ13C of n-Alkanes: Clean-Up Methods Appraisal and Application to Recent Sediments of a Highly Contaminated Bay

Compound-Specific δ13C of n-Alkanes: Clean-Up Methods Appraisal and Application to Recent Sediments of a Highly Contaminated Bay

Indicators of terrestrial biogenic hydrocarbon contamination and linear alkyl benzenes as land-base pollution tracers in marine sediments

Characterisation of the dynamics of organic contaminants ( n -alkanes, PAHs and PCBs) in a coastal area

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