Petroleum Inputs Research Articles

Molecular Fingerprinting of the Biodegradation of Petroleum Organic Pollutants in Groundwater and under Site-Specific Environmental Impacts

A quantitative and qualitative assessment using molecular markers derived from compound-specific indices for indicating groundwater impacted by petroleum spills in an oil field was recently undertaken and demonstrated serious contamination, with both high total petroleum hydrocarbons (TPH) (3.68–7.32 mg/L) and hazardous compounds in the groundwater. A petroleum source was identified, and the analysis revealed a decreasing trend of fresh petroleum input, along with groundwater advection and an increasing trend of biodegradation potential at locations farther from the source. This was confirmed via microbial analysis with both biodegrading microorganisms and diversity indices (Shannon, Simpson, and Pielou) and the principal component analysis (PCA) modeling approach, which classified the field samples into three types according to the distribution correlations between different organic compounds. Biodegradation was believed to be the dominant sink of hydrocarbons due to the increasing Pr/C17 and Ph/C18 values with seasonal changes. Raised temperatures activated the microbial degradation process; specifically, low-weight hydrocarbons degraded more rapidly than high-weight hydrocarbons, resulting in the accumulation of an unresolved complex mixture of bioproducts at locations that were farther away. Spatially, the Pr/C17 and Ph/C18 values increased from the upstream to the downstream areas, showing substantial biodegradation. The relationships between the molecular markers and chemical indices were quantified via canonical correlation analysis (CCA) to visually explain the interactive reaction processes. It was also demonstrated that the biodegradation of petroleum organics can be characterized by the consumption of dissolved oxygen and a decreasing Pr/Ph ratio, due to system reduction. These results demonstrate that compound-specific molecular markers, coupled with biochemical parameters, can effectively support a better understanding and effective fingerprinting of the fate and transport of petroleum organic contaminants, thus offering valuable technical support for a cost-effective remediation strategy.

Distribution, sources and ecological risks of PAHs and n-alkanes in water and sediments of typically polluted estuaries: Insights from the Xiaoqing River

Seasonal water and sediment samples were collected from the Xiaoqing River estuary and the neighboring sea to study the spatial and temporal distributions, sources and ecological risks of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes. The results showed significant spatial and temporal differences in the concentrations of PAHs and n-alkanes under the influence of precipitation, temperature, and human activities. The concentrations of PAHs in water were lower in the wet season than in the dry season, and those in sediments were higher in the wet season than in the dry season. The concentrations of n-alkanes were higher in the rainy season than in the dry season for both water and sediments. The spatial distributions of PAHs and n-alkanes were estuarine > offshore. The concentration ranges of ∑PAHs in water and sediments were 230.66–599.86 ng/L and 84.51–5548.62 ng/g, respectively, in the wet season and 192.46–8649.55 ng/L and 23.39–1208.92 ng/g, respectively, in the dry season. The proportion of three-ring PAHs in water (57.03% and 78.27% in the wet and dry seasons, respectively) was high, followed by two-ring PAHs (27.31% and 13.59% in the wet and dry seasons, respectively). The proportion of four-ring PAHs was higher in sediments (24.79% and 32.20% in the wet and dry seasons, respectively). The ecological risk of PAHs assessed using the toxicity equivalent quotient and risk quotient was at moderate to moderately high risk levels. The high concentration of n-alkane fraction C16 (611.65–75594.58 ng/L) in the water is indicative of petroleum or other fossil fuel inputs. The main peaks of n-alkanes in river sediments were C27, C29 and C31, indicating higher inputs of plant sources. The sediments in the estuary showed dominance of both short-chain C16 and long-chain C25–C31, indicating a combined input of higher plants and petroleum. The diagnostic ratios of PAHs and n-alkanes indicated that their sources were mainly oil/coal/biomass combustion and petroleum spills attributed to frequent vehicular, vessel and mariculture activities. Given the potential ecological risks of PAHs and n-alkanes in water and sediments, future studies should focus on their bioaccumulation and biotoxicity.

Mudskippers a good bioindicator for polluted soils in the mudflat region of southern Iraq

Mudskippers are good biological guide to marine pollution because they are endemic to the coastal areas of water that considered to be the original environment of life. Therefore, the area of Iraq's mudflats are affected by pollutants that reaching a narrow zone of Iraq and neighboring countries which regarded as oil activities area that directly affecting fishes due to increasing the likelihood of hydrocarbon accumulation. Besides, there are large ports of loading platforms nearby as well as this area regarded as a fishing ground. In the current study, hydrocarbons were analyzed using the mudskipper samples that were divided into three groups according on their length, which ranged from 11-16 cm, 17.5-19.5 cm and 20-23 cm, respectively, and the fishes were divided into three groups of weight; 7.13-17.33 g, 18.6-25.33 g and 26.7-36.6 g. Pollutant accumulation is a very reliable sign of environmental contamination. the ratio of Anthracene/(Anthracene+Phenanthrene) measured more than 0.1 (0.52, 0.62, 1.57) is in agreement with the combustion origin, Fluoranthene/(Fluoranthene +Pyrene) measured more than 0.35 which is in agreement with the prospect of petroleum input, and finally, the ratio of BaA/(BaA+Chry) measured about 0.16 in the third group which is attributable to cool combustion.

Combining theoretical concepts and Geographic Information System (GIS) to highlight source, risk, and hotspots of sedimentary PAHs: A case study of Chabahar Bay

Sedimentary PAHs are regionalized variables and their levels, source, and ecological hazards must be discussed in relation to their spatial locations. Our research targeted GIS and Chabahar Bay-Iran to trace spatial variability of PAHs, improve the diagnostic ratios and receptor models in source identification, and determine hotspot of PAH-originated hazards. The entropy Voronoi map distinguished an “entropy strip” in which ∑22PAHs levels increased sharply. Different molecular signatures were individually interpolated and the indicative ratios of distinctive sources were extracted and summed by GIS. The resulting code map reduced potential disagreement among molecular signatures and highlighted the areas where petroleum inputs are prevalent. PCA-MLR analysis extracted three potential sources including fossil fuel combustion (54.36%), petrogenic inputs (29.03%), and vehicle exhaust emissions (16.61%). Interpolated risk layers were re-arranged and overlaid via Fuzzy Membership Functions. The obtained ''Fuzzy AND" map showed the hotspot of the study area in the vicinity of a seasonal estuary.

The concentrations and sources of PAHs and PCBs in soil from an oil field and estuary in the Yellow River Delta, China

The occurrence of organic pollutants [i.e. polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs)] had been assessed in the soil samples collected from two sub-regions (an oil field and the Yellow River Estuary) in the Yellow River Delta (YRD), China. The concentrations of PAHs and PCBs in the soil were in the range of 157.8–481.7 μg kg−1 (dry weight) and 5.6–56.6 μg kg−1 (dry weight), respectively. The average concentration of PAHs in the soil samples from the oil field were 274.0 μg kg−1, and that in the estuary soil samples were 244.4 μg kg−1. The average concentration of PCBs in the soil samples from the oil field and the estuary were 24.2 μg kg−1 and 10.8 μg kg−1, respectively. The contribution of low molecular weight PAHs (two-ring and three-ring PAHs) was larger in the soil samples from the oil field than that in the estuary soil samples. Both PAHs and PCBs contaminations in the estuary area were lower than that in the oil field area. By using diagnostic ratios analysis, the main source of PAHs was attributed to petroleum input caused by the fuel oil or light refined petroleum products in the Gudong Oilfield. The amount of low-chlorine congeners (three to four chlorine atoms) PCBs in soil samples from the oil field were higher than that in the estuary soil samples. The congeners analysis of PCBs and the correlation analysis between the concentrations of PAHs and PCBs were employed. The results indicated that the emission of PCBs in YRD were influenced by both Gudong oilfield and other industrial sources.

Natural Asphalt Seeps Are Potential Sources for Recalcitrant Oceanic Dissolved Organic Sulfur and Dissolved Black Carbon.

Natural oil seepages contribute about one-half of the annual petroleum input to marine systems. Yet, environmental implications and the persistence of water-soluble hydrocarbons from these seeps are vastly unknown. We investigated the release of oil-derived dissolved organic matter (DOM) from natural deep sea asphalt seeps using laboratory incubation experiments. Fresh asphalt samples collected at the Chapopote asphalt volcano in the Southern Gulf of Mexico were incubated aerobically in artificial seawater over 4 weeks. The compositional changes in the water-soluble fraction of asphalt-derived DOM were determined with ultrahigh-resolution mass spectrometry (Fourier-transform ion cyclotron resonance mass spectrometry, FT-ICR-MS) and by excitation-emission matrix spectroscopy to characterize fluorescent DOM (FDOM) applying parallel factor (PARAFAC) analysis. Highly reduced aliphatic asphalt-derived DOM was readily biodegraded, while aromatic and sulfur-enriched DOM appeared to be less bioavailable and accumulated in the aqueous phase. A quantitative molecular tracer approach revealed the abundance of highly condensed aromatic molecules of thermogenic origin. Our results indicate that natural asphalt and potentially other petroleum seepages can be sources of recalcitrant dissolved organic sulfur and dissolved black carbon to the ocean.

Fingerprint analysis reveals sources of petroleum hydrocarbons in soils of different geographical oilfields of China and its ecological assessment

The distribution and characteristics of petroleum in three different geographic oilfields in China: Shengli Oilfield (SL), Nanyang Oilfield (NY), and Yanchang Oilfield (YC) were investigated. The average concentration of the total petroleum hydrocarbons (TPHs) conformed to be in the following law: SL Oilfield > NY Oilfield > YC Oilfield. Fingerprint analysis on the petroleum contamination level and source was conducted by the geochemical indices of n-alkanes and PAHs, such as low to high molecular weight (LMW/HMW) hydrocarbons, n-alkanes/pristine or phytane (C17/ Pr, C18/Ph), and ratio of anthracene/ (anthracene + phenanthrene) [Ant/(Ant + Phe)]. Soils adjacent to working well oils indicated new petroleum input with higher ratio of low to high molecular weight (LMW/HMW) hydrocarbons. The oil contamination occurred in the grassland soils might result of rainfall runoff. Petroleum source, petroleum combustion source, and biomass combustion were dominant PAHs origination of soils collected from oil exploitation area, petrochemical-related sites, farmland and grassland, respectively. The suggestive petroleum control strategies were proposed in each oilfield soils. Ecological potential risk of PAHs was assessed according to the toxic equivalent quantity (TEQ) of seven carcinogenic PAHs. The results showed that high, medium, and low ecological risk presented in petro-related area, grassland soils, and farmland soils, respectively. High ecological risk was persistent in abandoned oil well areas over abandoned time of 15 years, and basically stable after 5 years. This study can provide a critical insight to ecological risk management and source control of the petroleum contamination.

Geoderma Organic Geochemical Biomarkers for Estimation of Petroleum Inputs in Soil of Alluvial Area Near Sava River, New Belgrade (Serbia)

Geoderma Organic Geochemical Biomarkers for Estimation of Petroleum Inputs in Soil of Alluvial Area Near Sava River, New Belgrade (Serbia)

Persistent Organic Pollutants in Urban Soils of Central of London, England, UK: Measurement and Spatial Modelling of Black Carbon (BC), Petroleum Hydrocarbons (TPH), Polycyclic Aromatic Hydrocarbons (PAH) and Polychlorinated Biphenyls (PCB)

Total organic carbon (TOC), black carbon (BC), total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB) were determined in 73 surface (0-2 cm) and subsurface (5-20 cm) soil samples taken from a 142 km2 area in Central London, UK. Soils were assessed to provide a baseline chemistry for site owners, developers, occupiers and regulators involved in understanding the potential risk to human health and the environment. TOC range was 1.75-11.85 % (mean 5.82 %), BC 3.72-32.71 mg.g-1 (mean 13.8 mg.g-1), TPH 72-4673 mg.g-1 (mean 443 mg.g-1), Σ16PAH 1.64-421.23 mg.g-1 (mean 47.99 mg.g-1) and Σ7PCB 2.56-148.72 µg.kg-1 (mean 20.82 µg.kg-1). Surface soils were less polluted than sub-surface soils due to a decline in industry, power generation, coal burning and traffic. PAH and PCB showed a stronger affinity for BC than TOC and were higher than many other international cities. South east London (Greenwich, Woolwich, Deptford) had the highest PAH pollution. Source PAH ratios confirmed a combustion/urban road run-off origin with minor petroleum inputs. Random Forest spatial modelling (machine learning) revealed large scale pollution trends across London soils. Normal background concentrations (NBC) were calculated and compared to risk-based human health generic assessment criteria (GAC). Benz[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, and dibenzo[a]anthracene exceeded the Land Quality Management GACs for three land uses (residential, allotments and public open space near residential housing). The NBC determined for ∑7PCBs (110 µg.kg-1) and dioxin-like PCB 118 (59 µg.kg-1) exceeded the residential and allotment soil guideline values.

Characterization of marine microbial communities around an Arctic seabed hydrocarbon seep at Scott Inlet, Baffin Bay

Seabed hydrocarbon seeps present natural laboratories for investigating responses of marine ecosystems to petroleum input. A hydrocarbon seep near Scott Inlet, Baffin Bay, was visited for in situ observations and sampling in the summer of 2018. Video evidence of an active hydrocarbon seep was confirmed by methane and hydrocarbon analysis of the overlying water column, which is 260 m at this site. Elevated methane concentrations in bottom water above and down current from the seep decreased to background seawater levels in the mid-water column >150 m above the seafloor. Seafloor microbial mats morphologically resembling sulfide-oxidizing bacteria surrounded areas of bubble ebullition. Calcareous tube worms, brittle stars, shrimp, sponges, sea stars, sea anemones, sea urchins, small fish and soft corals were observed near the seep, with soft corals showing evidence for hydrocarbon incorporation. Sediment microbial communities included putative methane-oxidizing Methyloprofundus, sulfate-reducing Desulfobulbaceae and sulfide-oxidizing Sulfurovum. A metabolic gene diagnostic for aerobic methanotrophs (pmoA) was detected in the sediment and bottom water above the seep epicentre and up to 5 km away. Both 16S rRNA gene and pmoA amplicon sequencing revealed that pelagic microbial communities oriented along the geologic basement rise associated with methane seepage (running SW to NE) differed from communities in off-axis water up to 5 km away. Relative abundances of aerobic methanotrophs and putative hydrocarbon-degrading bacteria were elevated in the bottom water down current from the seep. Detection of bacterial clades typically associated with hydrocarbon and methane oxidation highlights the importance of Arctic marine microbial communities in mitigating hydrocarbon emissions from natural geologic sources.

Implications of anthropogenic effects on the coastal environment of Northern Persian Gulf, using jinga shrimp (Metapenaeus affinis) as indicator

The distribution and sources of PAHs in jinga shrimp (Metapenaeus affinis), and human health risks due to consumption was evaluated in collected samples from the Musa Bay, Persian Gulf. The total concentration of PAHs (∑16PAHs) ranged from 10 to 144 μg kg−1 dry weight, indicating low to moderate level of pollution. The PAHs were dominated by three- (41%) and two-ring (38%) compounds. Source identification analyses indicated the PAH pollution mostly originated from petroleum inputs. A preliminary evaluation of human health risk using chronic daily intake, hazard index, benzo[a]pyrene-equivalent (BaPeq) concentration (PEC) as well as the incremental life cancer risk and non-cancer risk assessment suggest low potential health risk for consumers of the Metapenaeus affinis. However, the results indicate minimal risks associated with the intake of PAHs via shrimp consumption, but long-term monitoring is required to evaluate the changes in ecological and human health impacts of contaminants in the region. Main findingPAHs in Metapenaeus affinis from Musa bay, which influenced by anthropogenic activities were low to moderate level of pollution. Human health risk indicates low potential health risk for consumers.

New insights into spatiotemporal source apportionment of n-alkanes under mixed scenario: A pilot study on Lake Chaohu, China

N–alkanes are ideal molecular markers for the source apportionment of organic matter. However, the estimation of both biogenic and anthropogenic sources under mixed scenario using n–alkanes and their related proxies still remains an issue. In this study, we investigated spatiotemporal variations of n–alkanes in suspended particulate matter of Lake Chaohu for their source apportionment. Overall, Σ29 n–alkanes ranged from 324.1 to 113685 ng·L−1. C17H36 was the most abundant homologue and was followed by C18, C27 and C29 homologues. Carbon preference indexes (CPIs) in most samples (at least 85%) were < 3, indicating mixed sources of n–alkanes in Lake Chaohu. Therefore, biogenic and anthropogenic n–alkanes were separated by subtraction to avoid potential bias. Our results showed Σ biogenic and Σ anthropogenic n–alkanes ranged from 14.8 to 3531.6 ng·L−1 and 257.6 to 4938.5 ng·L−1, respectively. For biogenic n–alkanes, their carbon–chain distributions posed a preponderant peak at C17, indicating algae were the main contributors to biogenic n–alkanes in Lake Chaohu. Biogenic average chain length (ACLbio) was developed to quantify the contributions of different biogenic sources. We recommended ACLbio < 21 for algae dominance and ACLbio > 26 for terrestrial plant dominance. For anthropogenic n–alkanes, their carbon–chain distribution presented obviously spatiotemporal variations. The sources of anthropogenic n–alkanes in summer and winter were typical dominances of light petroleum and incomplete fossil fuel burning/heavy oil emission, respectively. New developed proxies, anthropogenic average chain length (ACLanthro) and the ratio of unit short– to long–carbon anthropogenic n–alkanes (L/H), are effective for quantifying the relative contributions of different anthropogenic sources. We recommend log10L/H > 0.5 and ACLanthro < 20.5 for light petroleum input dominance, log10L/H < −0.5 and ACLanthro > 26.5 for incomplete fossil fuel burning at high temperature/heavy oil emission dominance.

Natural and anthropogenic organic matter cycling between coastal wetlands and rivers: a case study from Liao River Delta

Organic matter (OM) cycling between coastal wetlands and their connected rivers is poorly constrained due to difficulties in assessing the composition of different OM sources (natural vs. anthropogenic). Bulk characteristics and lipid biomarkers were analyzed to distinguish different sources of OM in the sediments and soils of Liao River Delta, Northeast China, including Liao River Wetland, its connected Liao River, and nearby Daliao River. A similar range of stable carbon isotopic values (δ13Corg) was observed in wetland soils (−27.8‰ to −22.6‰) and river sediments (−26.0‰ to −23.3‰). In contrast, significantly higher stable nitrogen isotopic values (δ15N) were observed in Daliao River sediments (5.8‰–7.7‰) than both Liao River and wetland soils. Lipid biomarkers, especially n-alkyl lipids, phytosterols, triterpenoids, isoprenoids, monoalkyl glycerol ethers, and monoacylglycerols, indicated that the natural OM input in Liao River Delta was mainly of terrestrial origin, followed by in situ aquatic and microbial inputs. In addition to natural OM, anthropogenic influences in the form of sewage and petroleum inputs were evidenced by the detection of fecal sterols, plasticizers, and petrogenic biomarkers. Biomarker distributions in samples from Liao River and Liao River Wetland suggested similar OM sources or close interaction between them, which may be caused by lateral transport considering the low elevation delta exposed to strong tidal effects. In contrast, significantly higher anthropogenic inputs were detected in Daliao River, with no connectivity to the Liao River wetland. Taking advantage of isotopic and biomarker data, the principal component analysis further suggests that both the natural wetland distribution and anthropogenic activities may affect the OM sources and distribution in coastal rivers, which serve as an important transit of OM to coastal oceans.

Sedimentary record of hydrocarbons and sewage inputs from a highly populated region in South-Eastern Brazil.

The environmental impacts of the urban expansion in Rio de Janeiro was evaluated based on the historical accumulation of black carbon (BC), aliphatic (AHs) and aromatic hydrocarbons (PAHs) and sterols in a sediment core retrieved from Botafogo Cove. BC related to oil combustion sources increased significantly since the 1990s. AHs were associated with petroleum inputs and revealed a high level of contamination. Multivariate statistical methods (a Principal Component Analysis associated with a linear multiple regression - PCA/LMR) applied to PAHs suggests changes in the sources in recent years. This can be ascribed to a reduction in pyrogenic emissions over the last four decades and to an increase in petrogenic inputs since the 1990s. The sterol dinosterol registered the increased eutrophication over the last three decades, but the sewage marker coprostanol was present at relatively low concentrations (0.40 to 1.16 μg g-1) probably caused by enhanced bacterial activity in the sediment.

Evaluation of macroalgae and amphipods as bioindicators of petroleum hydrocarbons input into the marine environment

The brown alga Sargassum furcatum and three families of amphipods (Ampithoidae, Caprellidae and Hyalidae) associated to that algae were evaluated as bioindicators of petroleum hydrocarbons input into the marine environment of São Sebastião Channel, in southeastern region of Brazil. The n-alkanes pattern were mainly associated with the natural composition of the macroalgae and amphipods, although some indicatives of petroleum hydrocarbons such as unresolved complex mixture and the no predominance of odd over even n-alkanes have been observed in some samples. Total PAHs ranged from 33.4 to 2010 ng g−1 dry weight with the predominance of low molecular weight PAHs, mostly of naphthalene and alkyl-naphthalenes, which also suggested petroleum input. Even in low concentration, Sargassum furcatum and amphipods species studied seems to be good indicators of the introduction of petroleum hydrocarbons.

Bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in wild marine fish from the coastal waters of the northern South China Sea: Risk assessment for human health

Little data are available on polycyclic aromatic hydrocarbons (PAHs) in marine fish associated with oil and gas activities from the South China Sea (SCS). Twenty-one wild marine fish species from the northern South China Sea were collected for analysis of the presence of polycyclic aromatic hydrocarbons (PAHs). The total concentration of the PAHs (∑16PAHs) ranged from 199 to 606 ng·g−1 d.w., indicating moderate contamination. PAHs in fish species found in the Pearl River Delta (PRD) were significantly higher than those from the Yachen (YC) gas fields (p < 0.05). Planktivorous fish exhibited significantly higher concentrations of PAHs than carnivorous and omnivorous fish (p < 0.05). The PAHs were dominated by three ring compounds. Source identification analyses indicated that the PAH pollution originated from petroleum inputs. The cancer and non-cancer risk assessments concluded that the probable risk associated with the intake of PAHs via fish consumption is minimal. Long-term monitoring is necessary to determine the ecological impacts of PAHs associated with oil and gas activities.

Polycyclic Aromatic Hydrocarbons (PAHs) in Urban Street Dust of Huanggang, Central China: Status, Sources and Human Health Risk Assessment

ABSTRACT Twenty-one street dust samples were collected in Huanggang City, Hubei Province, Central China. Sixteen priority polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography–mass spectrometry (GC-MS). Concentrations of ∑16PAHs ranged from 622.97 µg kg–1 to 4340.67 µg kg–1 with an average of 1862.10 µg kg–1. Among these PAHs, high-molecular-weight PAHs (four to six rings), which are the predominant PAH contributors in street dust, accounted for 55%–73% of the total PAHs. Mean concentrations of the PAHs among the four functional districts followed the order: education district > traffic area > business district > residential area. However, the individual PAH concentrations exhibited weak correlations with the total organic carbon. Based on the isomer ratios of the PAHs, biomass and coal combustion, and petroleum input were two key factors controlling PAH levels in this study. At a 95% confidence interval, the total incremental lifetime cancer risks for children, adolescents and adults approximated 10–6–1.5 × 10–5. These values were higher than the baseline value for acceptable risk (10–6), indicating a potential carcinogenic risk.

Entropy-weighted comprehensive evaluation of petroleum flow in China during 1980–2015

Abstract Based on a Material Flow Analysis (MFA) framework, a system of Material Flow Indicators for Petroleum Flows (MFIs-PF) in China during 1980–2015 was established and Comprehensively Evaluated (CE) using the entropy method. The comprehensive evaluation represented petroleum flows efficiency in terms of three different aspects: petroleum inputs, flows, and outputs. The CE results showed that petroleum flows efficiency exhibited a slow increase by 45%, with fluctuations for the period 1980–2015. However, there were significant differences among the developmental trajectories of the MFIs-PF. With respect to inputs indicators, direct petroleum inputs occupied the biggest weight in MFIs-PF system, furthermore, the direct petroleum inputs and dependence on petroleum imports grew rapidly, increasing from 106 million tonnes and 0.3% in 1980 to 550 million tonnes and 61% in 2015, respectively. Regarding flows indicators, the growth rate of petroleum production was slower than that of petroleum consumption, and the average of elasticity of petroleum production and consumption were approximately 0.23 and 0.73, respectively. In addition, the increase of the net addition to stocks reduced fluctuations in CE since 2010. Output indicators played a negative role in the development of petroleum flow efficiency and increased environmental load. Petroleum-related CO2 emissions grew by 4.3 times with the increase in petroleum consumption from 1980 to 2015 and expected to peak in 2035. While indirect CO2 emissions of petroleum flows processes fluctuated within the range of 96–217 kg CO2/t petroleum, with an average of 153 kg CO2/t petroleum. Driven by the policies, broadening the sources of petroleum imports, increasing domestic petroleum stock, and improving the efficiency of petroleum utilization are effective measures to increase the petroleum flows efficiency.

Source and composition of sedimentary organic matter in the head of Three Gorges Reservoir: a multiproxy approach using δ13C, lignin phenols, and lipid biomarker analyses

A multiproxy approach including bulk organic carbon, δ13C, lignin phenols, and lipid biomarker analyses were applied to characterize the source and composition of sedimentary organic matter in the head part of Three Gorges Reservoir. OM consisted of both natural (autochthonous and allochthonous) and anthropogenic inputs. The natural OM included input from vascular plants, especially non-woody angiosperms. The allochthonous input included plankton and microbial production, likely due to localized eutrophication. Anthropogenic inputs likely derived from petroleum input and/or urban activities. Other anthropogenic inputs were untreated sewage waste. These influences were concluded to be regionally specific point sources of pollution based on relative distributions and on the fact that molecular characteristics of sedimentary OM were not distributed smoothly along a gradient.

Occurrence, source and ecological assessment of baseline hydrocarbons in the intertidal marine sediments along the shoreline of Douglas Channel to Hecate Strait in British Columbia

The occurrence, source and ecological assessment of baseline hydrocarbons in the intertidal zone along the northern British shoreline were evaluated based on analyzing total petroleum hydrocarbons (TPH), n-alkanes, petroleum related biomarkers such as terpanes and steranes, and polycyclic aromatic hydrocarbons (PAHs) including non-alkylated and alkylated homologues (APAHs). The TPH levels, n-alkanes, petroleum biomarkers and PAHs in all the sampling sites, except for Masset Harbor/York Point at Gil Island were low, without obvious unresolved complex mixture (UCM) and petroleum contamination input. Specifically, n-alkanes showed a major terrestrial plants input; PAHs with abundant non-alkylated PAHs but minor APAHs showed a major pyrogenic input. However, obvious petroleum-derived hydrocarbons have impacted Masset Harbor. A historical petroleum input was found in York Point at Gil Island, due to the presence of the low level of petroleum biomarkers. Ecological assessment of 13 non-alkylated PAHs in Masset Harbor indicated no potential toxicity to the benthic organisms.