Hydrocarbons in coastal sediments from the Mediterranean sea (Gulf of Fos area, France)

Sedimentary hydrocarbons have been studied quantitatively and qualitatively in 11 coastal stations located in the Gulf of Fos (French Mediterranean coast). Hydrocarbon levels ranged from 10 to 260 mg kg(-1) sed. dry weight. A new parameter "NAR" (Natural n-alkane ratio) is proposed to evaluate the contribution of terrestrial inputs of hydrocarbons in the sediments. The origins of hydrocarbons are multiple: terrestrial inputs, biogenic, pyrolytic (industry emissions mainly steel and iron industries, ship and road traffic). Generally, the main source of contamination is not petroleum. Several ratios between parent polycyclic aromatic hydrocarbons show that the sources of hydrocarbons in the sediments are generally much more pyrolytic than petrogenic.     

Aliphatic and aromatic hydrocarbons in benthic invertebrates from two sites in Antarctica

Samples of marine benthic invertebrates collected from two sites in the Antarctic have been analysed for both aliphatic and aromatic hydrocarbons in order to establish baseline concentrations for some classes of hydrocarbons.Samples from Signy Island, a pristine site, contained low concentrations of the hydrocarbons determined, whereas those from King Edward Cove, South Georgia, contained significantly higher concentrations. King Edward Cove has a known history of pollution from whaling operations.Platt & Mackie (1979) have suggested that the hydrocarbons in sediments from King Edward Cove are a result of the world-wide dissemination of the pyrolysis products of fossil fuels. Our work suggests, in contrast, that the hydrocarbons in the benthos are derived from local sources.     

Aliphatic and polyaromatic hydrocarbons in bottom sediments of offshore mouth area of the Volga

Data on the concentration and composition of aliphatic and polyaromatic hydrocarbons in the surface layer and the body of bottom sediments in Volga delta and on the northern Caspian shelf are given. Volga delta sediments are shown to contain large concentrations of organic compounds. It is established that the concentrations of organic compounds is largely dependent on the dispersiveness of sediments. Anthropogenic hydrocarbons, both oil and pyrogenic, fail to pass the marginal filter of the Volga River and do not reach the open part of the sea. Therefore, the hydrocarbons contained in the bottom sediments on the Caspian Sea shelf are mostly of natural genesis. The distribution of organic compounds in the bottom sediment strata has a complex character. In some cases, their concentration increases because of the higher flux of hydrocarbons (especially, polyarenes in the 1950s).     

An Improved Gas Chromatographic Method for the Determination of C6–C12 Petroleum Hydrocarbons in Soil Water

In this work, investigations dealing with the determination of hydrocarbons in contaminated soil water are presented. The hydrocarbons under investigation range from low to high volatility compounds. A GC‐FID method was developed that due to its efficiency, routine suitability, relative rapidity, and low cost is suitable for the analysis of complex chemical mixtures of highly volatile hydrocarbons (with boiling points between 69 and 190°C). The standard used was a gasoline mixture with boiling points ranging from 100 to 190°C. For this standard, no supplementary preparation is needed and it is suitable for the whole range of hydrocarbons under investigation. The determination of the hydrocarbon content of the samples was performed applying univariate and multivariate statistical analysis to the experimental data. In the characterization of a contamination with highly volatile hydrocarbons of soil water originating from different depth layers from the chemistry location Leuna (Sachsen‐Anhalt, Germany), the advantages of a multivariate method are demonstrated in exemplary manner.     

Evidence for reduced post-spill recovery by the halophyte Sporobolus iocladus (Nees ex Trin.) Nees in oil-contaminated sediments

The germination behavior of Sporobolus iocladus seeds including germination percentage, accumulated germination percentage, the average incubation period to germination and germination velocity was studied under laboratory conditions. Treatments included six salinity regimes (0, 70, 140, 210, 280 and 350 mM NaCI) and three sources of oil hydrocarbons; Light Arabian Crude, polynuclear aromatic hydrocarbons (PAHs) including diaromatic or triaromatic hydrocarbons (in crude oil equivalent concentrations, COEC). The average incubation period needed for seeds to germinate was significantly longer for seeds germinated in 350 mM NaCl (6 +/- 1.16 days) compared with the control (4 +/- 00 days). The accumulated germination percentage gradually decreased with increasing salinity (control: 90 +/- 10, while 350 mM NaCl: 63 +/- 8.8). Oil hydrocarbons significantly affected all germination parameters of S. iocladus seeds regardless of salinity levels. COEC of di- and triaromatic hydrocarbons suppressed seed germination more than crude oil. Seeds exposed to diaromatic hydrocarbons failed to germinate. Hydrocarbon's salinity interaction significantly reduced the number of germinated S. iocladus seeds. It is concluded that hydrocarbon pollutants adversely affect S. iocladus through reducing germination. It is also suggested that the toxic effect of hydrocarbons on seeds is not solely mediated through their interaction with salinity. The ecological implications of these findings are discussed in relation to other studies on the post-spill recovery of halophytes.     

Inputs and sources of hydrocarbons in sediments from Cienfuegos bay, Cuba

The spatial distribution of aliphatic and polycyclic aromatic hydrocarbons (PAHs) was investigated in sediments from the Cienfuegos bay. The highest anthropogenic hydrocarbon inputs were found near the city of Cienfuegos with an unresolved complex mixture (UCM) of aliphatic hydrocarbons and alkylated PAHs, indicative of petrogenic inputs. Parent PAHs, which are typical of high-temperature combustion processes, were evenly distributed in the whole basin and largely prevailing in the southern part of the Cienfuegos city. Biomarker fingerprints assign the sources of pollution to mixes of national and non-national crude oils. The overall levels of anthropogenic hydrocarbons are relatively high compared to relevant areas worldwide and reveal a moderate/high level of hydrocarbon pollution. The Cienfuegos bay sediments received over a period of 5 yr, 50 T/yr of petrogenic unresolved hydrocarbons (UCM) and 2 T/yr of PAHs, being deposited the 80% in the sediments of the north basin.     

The concentration and composition of polyaromatic hydrocarbons in small rivers in the drainage area of the eastern Gulf of Finland

The results of examining the concentrations of 16 major polycyclic aromatic hydrocarbons are given. The examined samples were taken in the territory of Leningrad province and in the eastern Gulf of Finland in different seasons. Two seasonal natural profiles of polycyclic aromatic hydrocarbons were constructed, conventionally, for the spring and the autumn. The dominating effect on the formation of the profile of polycyclic aromatic hydrocarbons is exerted by pyrogenous pollution sources in winter and petrogenic pollution sources in summer.     

Petroleum and PAH contamination of the Black Sea

Concern has been expressed regarding the extent of contamination of the Black Sea. Analyses of coastal sediments taken from throughout the region indicate, however, that levels of petroleum hydrocarbons (2-300 microg g(-1) dry wt total hydrocarbons) are generally comparable to those encountered in the Mediterranean and are lower than concentrations reported for highly contaminated areas such as the Gulf, Hong Kong, Taiwan and New York Bight. Highest concentrations of total hydrocarbons (>100 microg g(-1) dry wt) were associated with discharges from Odessa, Sochi and the River Danube. Chronic/degraded petroleum was the major contributor at these sites. Samples from the Ukrainian coastline were comparatively clean (<10 microg g(-1) dry wt total hydrocarbons). Major contributions of fresh oil (as indicated by sigma n-C14-34) occur through the River Danube. Concerning total PAH, concentrations (7-638 ng g(-1) dry wt) compare to relatively unpolluted locations in the Mediterranean and are much lower than levels reported for polluted UK estuaries (e.g. Mersey, Tyne, Thames). Both pyrolytic and petrogenic PAH are present in most samples, although petroleum derived PAH are dominant at Sochi and pyrolytic sources are prevalent in the Bosphorus region. The absence of a correlation between total hydrocarbons and PAH (R2 = 0.04) indicates different primary sources for the two.     

Development of oil hydrocarbon fingerprinting and identification techniques

Oil, refined product, and pyrogenic hydrocarbons are the most frequently discovered contaminants in the environment. To effectively determine the fate of spilled oil in the environment and to successfully identify source(s) of spilled oil and petroleum products is, therefore, extremely important in many oil-related environmental studies and liability cases. This article briefly reviews the recent development of chemical analysis methodologies which are most frequently used in oil spill characterization and identification studies and environmental forensic investigations. The fingerprinting and data interpretation techniques discussed include oil spill identification protocol, tiered analytical approach, generic features and chemical composition of oils, effects of weathering on hydrocarbon fingerprinting, recognition of distribution patterns of petroleum hydrocarbons, oil type screening and differentiation, analysis of “source-specific marker” compounds, determination of diagnostic ratios of specific oil constituents, stable isotopic analysis, application of various statistical and numerical analysis tools, and application of other analytical techniques. The issue of how biogenic and pyrogenic hydrocarbons are distinguished from petrogenic hydrocarbons is also addressed.     

Origin of hydrocarbons in bottom sediments of the Ivankovo Reservoir

The composition of hydrocarbons (aliphatic and polycyclic aromatic) is studied in the surface layer of bottom sediments of the Ivankovo Reservoir. Their concentrations are found to be high both per dry mass and in the composition of C_org. The concentration range was 0.42 to 28.15% for C_org, 141.9 to 3451.8 μg/g for aliphatic hydrocarbons (0.2–51.2% C_org), and 28.2–9161 ng/g for polycyclic aromatic hydrocarbons ((0.04–6.58) × 10^?3 % C_org). The distribution of hydrocarbons is shown to be determined not only by the lithologic type of sediments, but also by their input from petroleum and pyrogenic sources.     

Hydrocarbons in the bottom sediments of the Northern Dvina estuary

The results of studying hydrocarbons during the flood in May 2005 are discussed. The concentration of aliphatic and polycyclic aromatic hydrocarbons are shown to match their concentrations in water areas with steady input of pollutants. Weathered oil and pyrogenic compounds dominated in their composition. The geochemical barrier the Northern Dvina River-Dvina Gulf is shown to become a filter during floods and prevents pollutants from penetrating into the White Sea.     

Interpretation of Gas Chromatographic Data in Subsurface Hydrocarbon Investigations

Capillary column gas chromatography (GC) is extremely useful in investigations of subsurface contamination by petroleum hydrocarbons. Fluid samples collected from observation wells are evaluated by GC methods to detect and analyze petroleum hydrocarbons in dissolved and liquid phases. The presence, types and concentrations of many petroleum-derived hydrocarbons dissolved in ground water can be determined. GC analysis can also be used to determine the composition of liquid hydrocarbon products, including gasoline, distillates and heavier oils. The degree of degradation of sampled liquid hydrocarbon product can be estimated from GC information, and this information can be helpful in estimating the length of time the product has been in the subsurface. Determination of the hydrocarbon source and migration path can be made from GC analysis of fluid samples collected at two or more locations.
This paper is intended to demonstrate interpretative techniques that can be used by hydrogeologists to facilitate the detection, identification and mitigation of subsurface hydrocarbons.     

Anthropogenic and Natural Components of Hydrocarbons in the Water of Lake Nero in Yaroslavl Oblast

The results of studies of spatial and seasonal variations in hydrocarbon concentrations in hypertrophic Lake Nero are used to discuss the problem of division of hydrocarbons into anthropogenic and natural components. It is shown that the use of bitumoids as a component of oil pollution instead of total organic matter can introduce errors in the results. Seasonal variations in the activity of hydrobionts in an undisturbed area are shown to have a notable effect on the assessment of the proportion of anthropogenic hydrocarbons in their total concentration, that is, on the assessment of the extent of pollution of water bodies. The natural component is found to dominate over the anthropogenic component only in the periods of algae blooming. In spring and autumn, the total concentration of hydrocarbons was found to exceed the MAC and to be due mostly to natural hydrobiological factors.     

Hydrocarbons in the intertidal environment of Kachemak Bay,Alaska

Intertidal animals and sediment from Kachemak Bay, Alaska were analysed to determine the concentrations of hydrocarbons. At Coal Point the herbivorous limpet Collisella pelta contained petroleum within its tissues while intertidal algae of the area have previously been shown to accumulate petroleum as a surface coating. At Coal Bay, a locality where both petroleum and coal are present, the filter feeding mussel Mytilus edulis contained petroleum hydrocarbons whereas the deposit feeding clam Macoma balthica contained an array of hydrocarbons suggesting detrital coal as the source. Animals higher in the food web including the gastropod Nucella lima and the urchin Strongylocentrotus droebachiensis showed no evidence of petroleum. All samples contained biogenic hydrocarbons of algal and planktonic origin.     

Natural and anthropogenic hydrocarbons in the Antarctic marine environment

The Antarctic marine environment contains a range of hydrocarbons at low concentrations, which are generally biogenic in origin. All major classes of hydrocarbons have been found in the Antarctic ecosystem. At present, anthropogenic input is very low and difficult to resolve from background levels. Pollution in the Antarctic is limited to only a few sources and although contamination can be locally chronic it is very restricted in extent. To date there have been few studies of hydrocarbon pollution and those available have been patchy in spatial coverage and generally lack time-series data. The low levels of natural hydrocarbons and restricted human activity make the Antarctic ecosystem suitable as an indicator of global hydrocarbon pollution.     

Polycyclic aromatic hydrocarbons in sediments of the Great Barrier Reef region,Australia

At present the concentrations of polycyclic aromatic hydrocarbons in sediments from the Great Barrier Reef are remarkably low. The baseline levels range from <0.01 μg kg^?1 dry wt. for benzo(k)fluoranthene and benzo(a)pyrene to <0.82 μg kg^?1 for chrysene. Measurable levels of polycyclic aromatic hydrocarbons have only been found in small areas close to sites frequently visited by power boats. Sediments from Townsville and Gladstone Harbours on the coast adjacent to the reef are polluted with polycyclic aromatic hydrocarbons to a similar degree to that reported for coastal sediments in similar locations in other parts of the world.     

Hydrocarbons in the modern sediments of the Caspian Sea

The presented results have been obtained in a study of the concentrations and composition of aliphatic and polycyclic hydrocarbons in bottom sediments of Volga delta branches and in its shallow zone (2009–2010), as well as the Caspian Sea proper (2010–2013). Oil hydrocarbon pollution has been found to manifest itself mostly in Volga delta branches, which, despite the low concentrations (up to 54.5 μg/g), showed higher hydrocarbons share in C_org (up to 33.8%), while the composition of alkanes suggested their oil genesis. The geochemical barrier the Volga–the Caspian Sea prevents anthropogenic hydrocarbons from entering the open parts of the Caspian. Bottom sediments in the shallow zone of the Northern Caspian, represented by coarse-grained material, are now polluted by oil hydrocarbons to a lesser extent compared with other areas. The highest concentrations of aliphatic hydrocarbons (up to 178 μg/g) were recorded in the deepsea bottom sediments of Derbent Depression and in depressions of the Middle and Southern Caspian. These areas show a higher concentration of C_org (up to 9.884%) and a low concentration of hydrocarbons in C_org (up to 0.16%), while odd high-molecular homologues (n-C₂₅–C₃₁) dominate in the composition of alkanes.     

The role of biogenic hydrocarbons in the assessment of oil pollution of freshwater bodies

The results of studying the concentrations and component composition of hydrocarbons and associated oxidized hydrophobic compounds in water bodies with different degrees of oil product pollution are given. It is shown that the role of biogenic hydrocarbons in the assessment of oil pollution of freshwater bodies, especially those having high biological productivity, can be quite significant. Such assessment requires the examination of their genesis by using the proposed gas-chromatographic and luminescent criteria. The most informative object for observations in the identification of oil and biogenic hydrocarbons for the assessment of chronic oil pollution of freshwater bodies is bottom sediment.     

Historical polycyclic aromatic and petrogenic hydrocarbon loading in Northern Central Gulf of Mexico shelf sediments

The distribution of selected hydrocarbons within ten dated sediment cores taken from the Mississippi River Bight off coastal Louisiana suggests a chronic contaminant loading from several sources including the river itself, oil and gas exploration in the central Gulf of Mexico (GOM) shelf area, and natural geologic hydrocarbon seeps. Data were grouped as either total polycyclic aromatic hydrocarbons (PAH's), which were indicative of pyrogenic PAH's; or estimated total hopanes (indicative of petrogenic hydrocarbons). The total PAH concentrations and estimated total hopanes begin increasing above background levels (approximately 200 ng g(-1)) after the 1950s. The distribution of these hydrocarbons and hopanes within the dated sediment cores suggests that the Mississippi River is a regional source of pyrogenic PAH's, and that the hopanes are from natural geologic hydrocarbon seeps, oil and gas exploration in the GOM, or both.     

Mathematical modeling of oil hydrocarbon transformations in different parts of the White Sea

The available observational data on variations of oil hydrocarbon concentrations in White Sea tributaries and in individual parts of the sea are analyzed, and the contributions of different external sources to marine environment pollution are evaluated. The results of calculations are used to determine the possible total input of hydrocarbons from additional potential sources—internal natural (production by microorganisms) and external anthropogenic (navigation and sea shipping), which are most active in the summer and autumn. The hydroecological CNPSi-model is used to reproduce the processes of pollution of nine areas in the White Sea by oil hydrocarbons and their subsequent biodegradation in the marine environment. The annual dynamics of hydrocarbon concentrations was calculated using the long-term annual observations of monthly variations of the temperature, light intensity, and transparency of water, data on the morphometry of sea areas (the squares, mean depths, and water volumes) and water exchange between the chosen areas, calculated by a hydrodynamic model. For large bays (Dvina, Kandalaksha), the calculated concentrations of oil hydrocarbons are shown to be in agreement with the available estimates (the mean and maximal concentrations). The annual variations of oil hydrocarbon concentrations; the biomasses, oxidation activity and bioproduction characteristics of oil hydrocarbon-oxidizing bacteria are characterized. The calculated internal fluxes of oil hydrocarbons (the inputs from different sources, horizontal transport, and biotransformation) were used to calculate their annual balances for individual areas and the sea as a whole, showing the balanced character of their fluxes with the total balance discrepancies for individual areas varying within 0.3–4.1%.