Hydrocarbons In Seawater Research Articles

Two types of microorganisms isolated from petroleum hydrocarbon pollutants: Degradation characteristics and metabolic pathways analysis of petroleum hydrocarbons.

The petroleum hydrocarbons in seawater have been worldwide concern contaminants. Biological method, with the advantages of low cost, minimal environmental impact, and no secondary pollution, is a promising method for petroleum hydrocarbon treatment. In this study, two strains, identified as Stenotrophomonas acidaminiphila and Ochrobactrum, were demonstrated to possess the ability to degrade petroleum hydrocarbons. The mixed culture composed of Stenotrophomonas acidaminiphila and Ochrobactrum at a 2:1 ratio was able to achieve 79.41% degradation of the total petroleum hydrocarbons after 5 days. Besides, the average removal efficiencies of C10-C30 components in petroleum hydrocarbons by Stenotrophomonas acidaminiphila, Ochrobactrum, and mixed culture were 62.98%, 59.14% and 73.30%, respectively. The possible degradation pathways of petroleum hydrocarbons had been speculated through gas chromatography-mass spectrometry (GC-MS) and differential gene expression metabolomics analyses. The toxicity of products from the biodegradation of petroleum hydrocarbons was greatly reduced.

Constructing perfluorinated UiO-67 for enrichment of polycyclic aromatic hydrocarbons in seawater and seabed sediments

To investigate the ocean contamination caused by polycyclic aromatic hydrocarbons (PAHs), UiO-67/perfluorooctanoic acid (UiO-67/PFOA) was synthesized through solvent-assisted ligand incorporation method. The UiO-67/PFOA was then served as an adsorbent in headspace solid-phase microextraction (HS-SPME) technology for collecting and concentrating trace PAHs. The addition of the PFOA improved the hydrophobicity and stability of the UiO-67/PFOA coating, and the C-F functional group in UiO-67/PFOA could form the pseudo hydrogen bonding with the C-H on the benzene ring of PAHs, which endowed the UiO-67/PFOA with 1.60-4.63 times enrichment performance for PAHs than UiO-67. Under optimal conditions, the wide linear ranges of PAHs (0.01-20 ng·mL−1) with good coefficients of determination (R2 ≥ 0.9950) and low limits of detection (LODs, 0.003-0.008 ng·mL−1) were obtained. The recoveries of five PAHs from spiked seawater and seabed sediment by the developed method ranged from 81.14% to 116.0% with satisfactory results. This work provided a good adsorbent for the enrichment of trace PAHs in complicated environments and a new approach for the subsequent synthesis of adsorbents with good enrichment performance.

Polycyclic aromatic hydrocarbons in seawater after the mysterious oil spill of 2019 on the Pernambuco coast, northeast Brazil

In 2019, one of Brazil's most significant environmental disasters occurred, involving an oil spill that directly affected Pernambuco state. Contamination along the coast was evaluated by the quantification of polycyclic aromatic hydrocarbons (PAHs) in fifty seawater samples collected in the summer and winter of 2021. Analysis using fluorescence spectroscopy revealed that for all the samples, levels of dissolved/dispersed petroleum hydrocarbons (DDPHs) were higher than the regional baseline for tropical western shores of the Atlantic Ocean. GC–MS analyses quantified 17 PAHs in the samples, with highest total PAHs concentrations of 234 ng L−1 in summer and 33.3 ng L−1 in winter, which were consistent with the highest risks observed in ecotoxicity assays. The use of diagnostic ratios showed that the coast was impacted by a mixture of PAHs from petrogenic and pyrolytic sources. The results indicated the need for continuous monitoring of the regions affected by the 2019 spill.

Hydrocarbons in Seawater and Fish, with a Special Focus on 16 EPA-PAHs in Marsa Matruh Sediments, Egyptian Mediterranean Sea

Hydrocarbons in Seawater and Fish, with a Special Focus on 16 EPA-PAHs in Marsa Matruh Sediments, Egyptian Mediterranean Sea

Hydrocarbons in Seawater and Fish, with a Special Focus on 16 EPA-PAHs in Marsa Matruh Sediments, Egyptian Mediterranean Sea

More emphasis is being paid to monitoring hydrocarbon levels and assessing their risk in various marine environmental matrices since they may pose a threat to biodiversity. This research highlighted hydrocarbons in the Marsa Matrouh coastal area of Egypt as the first comprehensive effort to provide a technical basis to assess and address pollution. Surficial sediments and seawater samples (in duplicate) were collected from 10 sites, Triplicate samples of nine fish species were collected from five stations (1, 3, 5, 7, 9) for THC determination. In addition, polycyclic aromatic hydrocarbons (PAHs) residues (16E PA-PAHs) were evaluated in the sediment. THC recorded concentrations of 14.77- 22.50 ng/l and 8.99-26.70 ng/l in water samples during summer and winter, respectively. The concentrations of 16∑ EPAPAHs in sediment ranged from 840 to 6860 ng/g, with an average of 2728 ng/g (dry weight). These values were < ERL (effective range low) and ERM (effective range medium) limits, while fish samples showed 17–35 ng/g of ∑PAHs. The sediment-water partition coefficient (LogKsw) ranged from 4.0–6.4, revealing the hydrophobicity of THC. Depending on the Ecological Hazard Quotient (EHA), none of the fish species evaluated in the study area posed any threat to human health. ƩCOMB (total combustion PAHs) recorded 3.17–0.31 ng/g, higher than total fossil hydrocarbons, and was declared a pyrolytic source of PAHs. The sum of seven carcinogenic PAHs (ΣCARC) ranged between 0.35–3.49 ng/g with an average of 1.31 ng/g. The total index values (< 4) indicate petrogenic origin for the recorded hydrocarbons.

The distribution and emission of CO2, CH4 and light hydrocarbons in an anticyclonic eddy of the Kuroshio extension

Mesoscale eddies are energetic and swirling circulations that frequently occur in the open ocean. The effects of mesoscale eddies on the biogeochemical cycling of climate-relevant gases remain poorly constrained. We investigated the distribution and air-sea fluxes of CO2, methane, and five non–methane hydrocarbons (NMHCs) in an anticyclone eddy of Kuroshio Extension during September 2019. Within eddy core, intense stratification hindered the replenishment of nutrients and favored the growth of small-size phytoplankton, such as Prochlorococcus. Seawater pCO2 decreased from 406.1 μatm at the eddy outside to 377.5 μatm at the eddy core, accompanied by a decrease in surface seawater temperature from 26.7 °C to 25.2 °C. The vertical distribution of methane (0.3-9.9 nmol L-1) was influenced by the eddy process, with a maximum at 80 m in the eddy core, which might be attributed to the degradation of phosphonates sustained by Prochlorococcus. The concentrations of five NMHCs (ethane, ethylene, propane, propylene, and isoprene) ranged from 17.2-126.2, 36.7-168.1, 7.5-29.2, 22.6-64.1, 54.5-172.1, 3.5-27.9 pmol L-1, respectively. Isoprene correlated well with Chl-a concentrations at the eddy core, while no significant correlation was observed at the eddy outside. Air-sea fluxes of CO2 and isoprene associated with the eddy core were higher than those of the eddy outside, while the maximum ventilation of methane and other NMHCs (ethane, ethylene, propane, and propylene) was found at the eddy outside. Collectively, physical processes such as eddies impact the production and distribution of light hydrocarbons in seawater and further influence their regional emissions to the atmosphere.

Molecular level insight into the different interaction intensity between microplastics and aromatic hydrocarbon in pure water and seawater

The interaction of MPs and aromatic hydrocarbons in seawater and pure water was examined using experimental measurements, molecular dynamics (MD) simulations, and density functional theory (DFT) calculations in light of the potential health risks posed by microplastic (MPs)-associated aromatic hydrocarbon pollutants. Isothermal studies and MD simulations suggested that MPs have a stronger affinity for aromatic hydrocarbons in seawater. To uncover the mechanism, MPs' surface characteristics and their intermolecular interactions with aromatic hydrocarbons were examined. According to the research, MPs in seawater have less compact structure, bigger pores, and a higher specific surface area, all of which contribute to more sorption sites. Analysis of the intermolecular interaction indicated that MPs have a greater ability for molecular interactions in seawater and the interaction energy between MPs and aromatic hydrocarbons in seawater is higher. Additionally, seawater cations may act as bridges, which also accelerate sorption in seawater. In summary, this study provides a molecular-level understanding of MPs-aromatic hydrocarbons interaction and demonstrates that the interaction is stronger in seawater.

Polycyclic aromatic hydrocarbons in seawater, surface sediment, and marine organisms of Haizhou Bay in Yellow Sea, China: Distribution, source apportionment, and health risk assessment

The pollution status of polycyclic aromatic hydrocarbons (PAHs) in seawater, surface sediment, and marine organisms was investigated in Haizhou Bay, which is a traditional marine fish farming region in China. The total concentrations of PAHs in seawater, surface sediment, and marine organisms were 12.4–40.3 ng/L (average 24.8 ng/L), 183.2–496.6 ng/g (average 293.5 ng/g), and 228.1–679.9 ng/g (average 392.6 ng/g), respectively. Source analysis results showed that the PAH sources for seawater and marine organisms were coal and biomass combustion (66.53%), petroleum (28.94%), and traffic (4.52%), while those for the surface sediment were traffic (48.14%), coal and biomass combustion (40.56%). The lifetime cancer risk increment (ILCR) values of marine organisms in the Haizhou Bay were less than 10−6, indicating no carcinogenic risk. In the future, this study can be used as a reference to understand the distribution and interrelation of PAHs in other semi-enclosed bays in the world.

Bioremediation of Petroleum Hydrocarbons in Seawater: Prospects of Using Lyophilized Native Hydrocarbon-Degrading Bacteria.

This work aimed to develop a bioremediation product of lyophilized native bacteria to respond to marine oil spills. Three oil-degrading bacterial strains (two strains of Rhodococcus erythropolis and one Pseudomonas sp.), isolated from the NW Portuguese coast, were selected for lyophilization after biomass growth optimization (tested with alternative carbon sources). Results indicated that the bacterial strains remained viable after the lyophilization process, without losing their biodegradation potential. The biomass/petroleum ratio was optimized, and the bioremediation efficiency of the lyophilized bacterial consortium was tested in microcosms with natural seawater and petroleum. An acceleration of the natural oil degradation process was observed, with an increased abundance of oil-degraders after 24 h, an emulsion of the oil/water layer after 7 days, and an increased removal of total petroleum hydrocarbons (47%) after 15 days. This study provides an insight into the formulation and optimization of lyophilized bacterial agents for application in autochthonous oil bioremediation.

Water column poly-aromatic hydrocarbon anomalies measured with submersible gliders in the Angolan natural oil seepage province

Fluorescence sensors mounted on unmanned underwater gliders open new ways of investigation to detect dissolved hydrocarbons in seawater. A glider was deployed for 20 days to monitor biogeochemical and physical signals associated with natural hydrocarbon seepages within the first 700 m in the Angolan waters. The glider was equipped with fluorometers (MiniFluo-UV) to measure the concentrations of polycyclic aromatic hydrocarbons (PAH) of interest, i.e. naphthalene, phenanthrene, fluorene and pyrene. A continuous PAH-like signal detected within the 70 m layer below the sea surface is associated with high chlorophyll concentration in the deep chlorophyll maximum. Vertical PAH-like anomalies forming either strong spikes or diffuse columns down to 700 m are observed at the exact location of oil seep sites identified on Synthetic Aperture Radar satellite images. An ~200 m thick layer of enhanced PAH-like concentration, topped by a thermo/pycnocline identified at 280–300 m water depth, is measured in concomitance with the decrease in oxygen concentration. The concomitance of these signals suggests that lower oxygen concentrations induce a preservation of hydrocarbons within the eastern Atlantic oxygen minimum zone. Even if the absence of in-situ measurements limits the understanding of physical and biogeochemical processes affecting PAH concentrations, the measurements conducted at the edges of the OMZ suggests a relationship with microbial activity and organic matter dynamics in this layer. The results presented here show that gliders equipped with PAH sensors represent a promising means for monitoring hydrocarbons in the oceans, especially when they are coupled with other systems (i.e. Synthetic Aperture Radar).

A method for calibrating seawater polyaromatic hydrocarbons sensor

To solve the problems in the calibration of polyaromatic hydrocarbons sensor used in seawater, we proposed a new method that using 1,5-Naphthalenedisulfonic acid, disodium salt dihydrate instead of polyaromatic hydrocarbons standard substances to calibrate seawater polyaromatic hydrocarbons sensor. Relative to polyaromatic hydrocarbons standard substances, 1,5-Naphthalenedisulfonic acid, disodium salt dihydrate shows higher solubility in seawater, better stability under the detection wavelength of polyaromatic hydrocarbons and lower toxicity to organisms. Our results showed that the relative errors between real concentrations of standard substances and measuring concentrations of these standard substances via 1,5-Naphthalenedisulfonic acid, disodium salt dihydrate-calibrated sensor varied from 5~15%. Our method can reduce the complexity of calibration procedures, and keep the accuracy and precision of sensors in the determination of polyaromatic hydrocarbons in seawater.

Spatial-temporal distribution of polycyclic aromatic hydrocarbons in seawater at West Nanao Bay, Noto Peninsula

Spatial-temporal distribution of polycyclic aromatic hydrocarbons in seawater at West Nanao Bay, Noto Peninsula

Current level of oil hydrocarbons in Russian coastal waters of the Black Sea and and Azov Sea

Aim. Currently, oil pollution remains one of the primary pollutants of the marine environment. This is especially true for the Black Sea and Azov Sea which experience significant anthropogenic pressure. The study presents the results of two-year monitoring studies of the content of oil hydrocarbons in the surface and bottom horizons of the coastal waters of the Azov-Black Sea regions of Russia.Materials and Methods. The determination of oil hydrocarbons was conducted by infrared spectrometry using a FSM-1201 Fourier spectrophotometer with preliminary transmission of the extracts through a chromatographic column with aluminum oxide. The work was carried out as part of five scientific expeditions (93th, 96th, 100th, 102nd and 105th) of the research vessel, Professor Vodyanitsky, in 2017 and 2018.Results. The general environmental status for this pollutant is characterized as stable, despite in some cases being 3 to 4 times in excess of established standards (MPC). Separate foci of localized oil pollution have been identified and vulnerable areas of the sea coast of southern Russia have been identified. An excess content of petroleum hydrocarbons in the surface layer compared to the bottom layer was noted, which indicates a surface path of entry of petroleum products into sea water.Conclusion. Currently, the coastal waters of the western part of Crimea are most affected by oil, primarily associated with the runoff of European rivers and the peculiarities of the marine hydrological regime, including the Kerch Strait, an area of heavy shipping traffic. The Caucasian coast is less affected by oil pollution than the Crimean. Despite the fact that currently the content of oil hydrocarbons in sea water is far from the quantities dangerous to humans and aquatic organisms, monitoring of this indicator is vital due to the increasing anthropogenic pressure on the recreational zones of the Crimean and Caucasian coasts of the Russian Federation.

A turn-off luminescent europium probe for efficient and sensitive detection of some low molecular weight polycyclic aromatic hydrocarbons in seawater

Eu(III)-(CCA)2 complex probe was applied for the direct detection of polycyclic aromatic hydrocarbons PAHs naphthalene, anthracene, acenaphthene or fluorene in seawater samples were collected from Suez Bay. The low limit of detection and the quantification limit were calculated for all compounds under study. The selectivity of the probe was characterized through studying the effect of some interfering ions. The results obtained from fluorimetric method using Eu(III)-(CCA)2 probe was validated through using gas chromatography and arecoverymethod. The developed Eu(III)-(CCA)2 probe has the ability for detecting PAHs in rapid and straightforward procedure even in presence of interfering metal ions. The data indicated that the Eu(III)-(CCA)2 probe is suitable for direct and efficient determination of PAHs compounds from seawater.

Development of a computational method to quantify the partitioning of polycyclic aromatic hydrocarbons in seawater into dissolved and droplet forms

The ecological risk and potential injury from polycyclic aromatic hydrocarbons (PAHs) from spilled crude oil in water is dependent on whether they are dissolved or associated with droplets/particles. Using oil collected from the Deepwater Horizon incident, laboratory experiments were conducted to develop a computational method to determine the physical state of PAHs in sampled seawater and compare these to results from methods designed to physically separate dissolved and droplet oil used during the spill. The analytical results were used to develop a method to calculate droplet/particulate concentrations from unfractionated water samples based on oil composition and allocation of minimally soluble oil components to the droplet fraction. The computational method is less labor-intensive and costly than field fractionation and can be used to optimize the use of previously collected data. The results also showed that physical separation can result in insoluble high-molecular-weight PAHs being present in the filtrate (i.e., the “dissolved” fraction), potentially leading to an overestimate of dissolved components.

Temporal Variations of Polycyclic Aromatic Hydrocarbons in the Seawater at Tsukumo Bay, Noto Peninsula, Japan, during 2014-2018.

Concentrations of phase-partitioning 13 polycyclic aromatic hydrocarbons (PAHs) in seawater were investigated in the Tsukumo Bay, Noto Peninsula, Japan, during 2014–2018, to improve the understanding of the environmental behavior of PAHs in the coastal areas of the Japan Sea. Total PAH (particulate plus dissolved) concentrations in surface seawater were in the range 0.24–2.20 ng L−1 (mean 0.89 ng L−1), an order of magnitude lower than the mean values observed in the Japan Sea in 2008 and 2010. Although the PAH contamination levels during 2014–2018 were significantly lower than those in the East China Sea, the levels increased from 2014 to 2017 and were maintained at the higher level during 2017–2018. The main sources of particulate and dissolved PAHs during 2014–2018 were combustion products, of which the former were more influenced by liquid fossil-fuel combustion and the latter by biomass or coal combustion. The increase in particulate PAH concentrations in October–December during 2014–2018 was due to the impact of PAH-rich airmasses transported from the East Asian landmass in the northwesterly winter monsoon winds. The increase in dissolved PAH levels during July–September in 2014, 2016, 2017, and 2018 indicates that the Tsukumo Bay is possibly impacted by the PAH-rich summer continental shelf water transported by the Coastal Branch of the Tsushima Warm Current, which flows into the Japan Sea from the East China Sea.

Biodegradation of aliphatic and polycyclic aromatic hydrocarbons in seawater by autochthonous microorganisms

The bioremediation of petroleum spills in marine environments is still a challenge nowadays, and the technology available towards this goal must be improved. The search for efficient and applicable systems requires the prospection, isolation and characterization of autochthonous microorganisms with potential for bioremediation. Here, microorganisms were isolated from “Lagoa do Peixe” National Park, a site with a history of frequent petroleum spills in Brazil. The isolation methodology was based on the enrichment of microorganisms able to biodegrade petroleum hydrocarbons. After preliminary tests of 2,3,5-triphenyl tetrazolium chloride (TTC) redox indicator, two bacteria were able to produce biosurfactants and metabolize complex carbon sources in a solid medium: Bacillus methylotrophicus SSNPLPB5 and Pseudomonas sihuiensis SNPLPB7. Biodegradation assays using aliphatic and polycyclic aromatic hydrocarbons (PAHs) sources showed that both bacteria are able to biodegrade: (i) up to 92.1% and 42.4% of the medium (C8 to C19) and long (C20 to C33) chain aliphatic contaminant fraction, respectively; (ii) 31.1% of isoprenoid (pristane) and (iii) 46% of anthracene, 33.9% of phenanthrene and 35.3% of pyrene, after 46 days of incubation in seawater. The isolates were shown to produce biosurfactants such as surfactins, iturins, mono- and di-rhamnolipids, which reduced the surface tension, pH and showed emulsifying activity of the cell-free supernatant at the end of the incubation time, with potential application in petroleum spills bioremediation.

Investigation of Polycyclic Aromatic Hydrocarbons in Seawater Collected From Lebanese Coast

Investigation of Polycyclic Aromatic Hydrocarbons in Seawater Collected From Lebanese Coast

Multivariate optimization of an extraction procedure based on magnetic molecular imprinted polymer for the determination of polycyclic aromatic hydrocarbons in sea water

The present work deals with the optimization of a magnetic solid phase extraction of polycyclic aromatic hydrocarbons (PAHs) from sea water, based on molecular imprinted microparticles, for subsequent GC–MS analysis. The extraction efficiency of the magnetic molecular imprinted polymer (MIP) was compared with that of the corresponding non-imprinted polymer; only small differences in the recovery of the extraction procedure were shown, but higher repeatability was observed using MIP. An experimental design (Plackett-Burman) allowed a fast optimization identifying the only significant factor influencing the extraction recovery, namely the ratio between the amount of microparticles and the sample volume. Two optimal ratios, based on the PAHs molecular weight, were selected for 20 mL of sea water samples: 5 mg or 20 mg of microparticles for compounds ranging from 128 to 228 and from 252 to 278 Da, respectively. The recoveries ranges were 76–104% for the low molecular weight PAHs and 95–101% for the high molecular weight PAHs. The analytical method showed satisfactory figures of merit, with detection limits ranging from 30 to 375 ng L−1 and relative standard deviations on replicate extractions from 3.7 to 12.2%. The developed method, which is fast, easy and requires very small volumes of organic solvent, was applied for the determination of PAHs in selected sea water samples.

Degradation of petroleum hydrocarbons in seawater by simulated surface-level atmospheric ozone: Reaction kinetics and effect of oil dispersant

Oil degradation by surface-level atmospheric ozone has been largely ignored in the field. To address this knowledge gap, this study investigated the ozonation rate and extent of typical petroleum compounds by simulated surface-level ozone, including total petroleum hydrocarbons (TPHs), n-alkanes, and polycyclic aromatic hydrocarbons (PAHs). Moreover, the work explored the effect of a prototype oil dispersant, Corexit EC9500A, on the ozonation rate. Rapid oxidation of TPHs, n-alkanes and PAHs was observed at various gaseous ozone concentrations (i.e. 86, 200 and 300 ppbv). Generally, the presence of the oil dispersant enhanced ozonation of the oil compounds. The addition of humic acid inhibited the reaction, while increasing salinity accelerated the degradation. Both direct ozonation by molecular ozone and indirect oxidation by ozone-induced radicals play important roles in the degradation process. The findings indicate that ozonation should be taken into account in assessing environmental fate and weathering of spilled oil.