This paper presents concentrations and sources of Aliphatic and Aromatic Hydrocarbons in the sediments from Babolsar coastal area and the inlet of Babolrood River in the southern side of the Caspian Sea. The concentration of hydrocarbons in 13 sediment samples from the study area were measured by gas chromatography (GC). Total Petroleum Hydrocarbon (TPH) concentrations in sediment samples in the coastal area ranged from 115 to 201 μg/g. In the inlet samples, TPH concentrations were close to each other and ranged from 294 to 367 μg/g. The TPH results showed moderate level of oil pollution in the study area. Total Polycyclic Aromatic Hydrocarbons (ΣPAHs) concentrations in sediment samples inside the inlet ranged from 498 to 702 ng/g, indicating moderate level of pollution. Concentrations of ΣPAHs in sediment samples in the coastal area ranged from 341 to 1703 ng/g, indicating moderate to less than significant level of pollution. Developed indices for pollutant origins showed that hydrocarbons in all sediment samples collected in the study area had petrogenic origin. The results also showed the Babolrood River as the main source of oil pollution in the sediments in the study area.

Kharg Island in the Persian Gulf is the place for the major oil export terminals of Iran and hosts several large oil related industries. Coastal environment of the Kharg Island is rich in coral reefs. This paper presents concentrations and sources of aliphatic and aromatic hydrocarbons in the sediments from the coastal area of the island. The concentration of hydrocarbons in 14 seabed sediment samples from water depths of 13-20 m around the island were measured by gas chromatography (GC). Total Petroleum Hydrocarbon (TPH) concentrations in sediment samples ranged from less than 1 to 133 μg/g indicating low to moderate levels of oil pollution. Spatial distributions of TPH concentrations indicated no oil pollution in the southern part of the island, higher oil pollution levels near oil terminals and correlation with fine particles. Total Polycyclic Aromatic Hydrocarbons (∑PAHs) concentrations in sediment samples ranged from near zero to 6210 ng/g, indicating non to highly, but mainly moderately polluted levels. SPAHs concentrations, except at one station, were all less than the NOAA sediment quality guideline value for the effects range low. Developed indices for pollutant origins showed that hydrocarbons in all sediment samples collected in the study area had petrogenic origin. The results also indicated that the emissions from gas flares in the island were the main source of aromatic compounds in the sediment samples.

International audience | Although high PAH content and detection of PAH-degraders, the PAH biodegradation is limited in aged-contaminated soils due to low PAR availability (i.e., 1%). Here, we tried to experimentally increase the soil PAH availability by keeping both soil properties and contamination composition. Organic extract was first removed and then re-incorporated in the raw soil as fresh contaminants. Though drastic, this procedure only allowed a 6-time increase in the PAH availability suggesting that the organic constituents more than ageing were responsible for low availability. In the re-contaminated soil, the mineralization rate was twice more important, the proportion of 5-6 cycles PAH was higher indicating a preferential degradation of lower molecular weight PAH. The extraction treatment induced bacterial and fungal community structures modifications, Pseudomonas and Fusarium solani species were favoured, and the relative quantity of fungi increased. In re-contaminated soil the percentage of PAH-dioxygenase gene increased, with 10 times more Gram negative representatives.

International audience | An original combined organic geochemistry and soil science approach was used to elucidate PAH availability controlling factors in a multi-contaminated industrial soil. Water granulodensimetric fractionation was applied to obtain five water-stable material fractions. These were characterized by elemental, molecular and mineral analysis, and microscopic observations. Among the different fractions, fine silts distinguished themselves by higher carbon and nitrogen contents, lower C/N ratio, an enrichment in total PAH and especially high molecular weight compounds, a coal tar signature and the lowest PAH availability. This fine silt fraction seemed to play a protective role for PAH that might be explained by its size and/or its specific reactivity. The mineral phases present in this fraction were proposed to explain the protection of organic matter. This led to a specific molecular signature of OM, having higher sorption properties both processes (sorption and mineral-bound protection) resulting in a lower PAH availability. (C) 2013 Elsevier Ltd. All rights reserved.

International audience

We investigated the biological response of soluble organic fraction (SOF) and water-soluble fraction (WSF) extracted from particulate matter (PM) emitted by an automotive diesel engine operating in a representative urban driving condition. The engine was fueled with ultra-low sulfur diesel (ULSD), and its binary blends by volume with 13% of butanol (Bu13), and with hydrotreated vegetable oil (HVO) at 13% (HVO13) and 20% (HVO20). Cytotoxicity, genotoxicity, oxidative DNA damage and ecotoxicity tests were carried out, and 16 polycyclic aromatic hydrocarbons (PAH) expressed as tbenzo(a)pyrene total toxicity equivalent (BaP-TEQ) were also analyzed. The Hepatocarcinoma epithelial cell line (HepG2) was exposed to SOF for 24 h and analyzed using comet assay, with the inclusion of formamidopyrimidine DNA glycosylase (FPG) and endonuclease III (Endo III) to recognize oxidized DNA bases. The WSF was evaluated through acute ecotoxicity tests with the aquatic microcrustacean Daphnia pulex (D. Pulex). Results showed that there was no cytotoxic activity for all tested SOF concentrations. Genotoxic responses by all the SOF samples were at same level, except for the HVO13 which was weaker in the absence of the enzymes. The addition of the FPG and Endo III enzymes resulted in a significant increase in the comet tail, indicating that the DNA damage from SOF for all tested fuel blends involves oxidative damage including a higher level of oxidized purines for ULSD and Bu13 in comparison with HVO blends, but the oxidized pyrimidines for HVO blends were slightly higher compared to Bu13. The WSF did not show acute ecotoxicity for any of the fuels. Unlike other samples, Bu13-derived particles significantly increase the BaP-TEQ. The contribution to the genotoxic activity and oxidative DNA from SOF was not correlated to BaP-TEQ, which means that the biological activity of PM might be affected also by other toxic compounds present in particulate phase.

Capping represents an efficient and well-established practice to contain polycyclic aromatic hydrocarbons (PAHs) in sediments, reduce mobility, and minimize risks. Exposure to PAHs can encourage biodegradation, which can improve the performance of capping. This study investigates biodegradation of naphthalene (a model PAH) in highly reducing, sediment-like environments with amendment of different capping materials (PAC and sand). Microcosms were prepared with sediment enrichments, sulfate as an electron acceptor, and naphthalene. Results show that PAC stimulates naphthalene biodegradation and mineralization, as indicated by production of ¹⁴CO₂ from radiolabeled naphthalene. Mineralization in PAC systems correlates with the enrichment of genera (Geobacter and Desulfovirga) previously identified to biodegrade naphthalene (Spearman’s, p < 0.05). Naphthalene decay in sand and media-free systems was not linked to biodegradation activity (ANOVA, p > 0.05), and microbial communities were correlated to biomass yields rather than metabolites. Naphthalene decay in PAC systems consists of three stages with respect to time: latent (0–88 days), exponential decay (88–210 days), and inactive (210–480 days). This study shows that PAC amendment enhances naphthalene biodegradation under strictly sulfate-reducing conditions and provides a kinetic and metagenomic characterization of systems demonstrating naphthalene decay.

There is currently great interest in replacing fossil-oil with renewable fuels in energy production. Fast pyrolysis bio-oil (FPBO) made of lignocellulosic biomass is one such alternative to replace fossil oil, such as heavy fuel oil (HFO), in energy boilers. However, it is not known how this fuel change will alter the quantity and quality of emissions affecting human health. In this work, particulate emissions from a real-scale commercially operated FPBO boiler plant are characterized, including extensive physico-chemical and toxicological analyses. These are then compared to emission characteristics of heavy fuel-oil and wood fired boilers. Finally, the effects of the fuel choice on the emissions, their potential health effects and the requirements for flue gas cleaning in small-to medium-sized boiler units are discussed.The total suspended particulate matter and fine particulate matter (PM₁) concentrations in FPBO boiler flue gases before filtration were higher than in HFO boilers and lower or on a level similar to wood-fired grate boilers. FPBO particles consisted mainly of ash species and contained less polycyclic aromatic hydrocarbons (PAH) and heavy metals than had previously been measured from HFO combustion. This feature was clearly reflected in the toxicological properties of FPBO particle emissions, which showed less acute toxicity effects on the cell line than HFO combustion particles. The electrostatic precipitator used in the boiler plant efficiently removed flue gas particles of all sizes. Only minor differences in the toxicological properties of particles upstream and downstream of the electrostatic precipitator were observed, when the same particulate mass from both situations was given to the cells.

The Deepwater Horizon (DWH) disaster released crude oil in the Gulf of Mexico for 87 days, overlapping with the reproductive season and recruitment of the oyster Crassostrea virginica. The pelagic larval life stages of C. virginica are particularly vulnerable to contaminants such as polycyclic aromatic hydrocarbons (PAHs) and oil droplets. Based on their lipophilic properties, PAHs and oil droplets can adsorb onto phytoplankton and filter-feeding C. virginica larvae may be exposed to these contaminants bound to suspended sediment, adsorbed onto algal and other particles, or in solution. This study examined the effects of exposure of C. virginica larvae to algae mixed with DWH oil. In a 14-day laboratory exposure, 5 day-old C. virginica larvae were exposed to Tisochrysis lutea mixed with four concentrations of unfiltered DWH oil (HEWAF) in a static renewal system. Larval growth, feeding capacity, abnormality and mortality were monitored throughout the exposure. Total PAH (n = 50) content of the water medium, in which larvae were grown, were quantified by GC/MS-SIM. Oil droplets were observed bound to algae, resulting in particles in the size-range of food ingested by oyster larvae (1–30 μm). After 14 days of exposure, larval growth and survival were negatively affected at concentrations of tPAH50 as low as 1.6 μg L⁻¹. GC/MS-SIM analysis of the exposure medium confirmed that certain PAHs were also adsorbed by T. lutea and taken up by oyster larvae via ingestion of oil droplets and/or contaminated algae. Long-term exposure to chronic levels of PAH (1.6–78 μg tPAH50 L⁻¹) was shown to negatively affect larval survival. This study demonstrates that dietary exposure of oyster larvae to DWH oil is a realistic route of crude oil toxicity and may have serious implications on the planktonic community and the food chain.