Hydrocarbons In Surface Sediments Research Articles

Distribution, source, and ecological risks of polycyclic aromatic hydrocarbons in surface sediments from contaminated urban rivers across China

Distribution, source, and ecological risks of polycyclic aromatic hydrocarbons in surface sediments from contaminated urban rivers across China

Seasonal variations in the distribution of aliphatic hydrocarbons in surface sediments from the Selangor River, Peninsular Malaysia's West Coast.

The seasonal variation of petroleum pollution including n-alkanes in surface sediments of the Selangor River in Malaysia during all four climatic seasons was investigated using GC-MS. The concentrations of n-alkanes in the sediment samples did not significantly correlate with TOC (r = 0.34, p > 0.05). The concentrations of the 29 n-alkanes in the Selangor River ranged from 967 to 3711 µg g-1dw, with higher concentrations detected during the dry season. The overall mean per cent of grain-sized particles in the Selangor River was 85.9 ± 2.85% sand, 13.5 ± 2.8% clay, and 0.59 ± 0.34% gravel, respectively. n-alkanes are derived from a variety of sources, including fresh oil, terrestrial plants, and heavy/degraded oil in estuaries. The results of this study highlight concerns and serve as a warning that hydrocarbon contamination is affecting human health. As a result, constant monitoring and assessment of aliphatic hydrocarbons in coastal and riverine environments are needed.

The content and composition of organic compounds in the bottom sediments of the Norilsk-Pyasina water system one year after the accidental spill of diesel fuel

One year after the emergency diesel fuel spill in Norilsk, hydrocarbon concentrations in bottom sediments of the Norilsk-Pyasina water system decreased. However the average concentrations of hydrocarbons in surface sediments decreased in the same sequence (μg/g) as in 2020: the mouth of the Ambarnaya R. (835, σ = 1788) > Bezymyanny Cr.–the Daldykan R.–the Ambarnaya R. (306, σ = 273) > the Pyasina R. (23, σ = 20) > the Pyasino Lake (12, σ = 8). Concentrations decreased due to degradation of low molecular weight hydrocarbons. The content of polycyclic aromatic hydrocarbons in 2021 also changed in a smaller range (0–1027 ng/g) than in 2020 (0–3865 ng/g). Petroleum origin of polycyclic aromatic hydrocarbons in the sediments of the Ambarnaya R. (including the mouth), Bezymyanny Cr. and the Daldykan R. is confirmed by the dominance of alkylated naphthalene homologues in their composition. Hydrocarbons accumulation in some layers of the sedimentary column is caused not only by the spill of diesel fuel, but also by the organic matter from the surrounding swamps, from wetlands and floodplain lakes, as well as by the burial of the surface layer by the 2021 flood.

Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments of the East China marginal seas: Significance of the terrestrial input and shelf mud deposition

To investigate the distribution, sources, influencing factors, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in East China Marginal Seas (ECMSs) sediments, we measured the concentrations of 16 PAHs in 104 surface sediment samples collected from the ECMSs in 2014 and 2016. Total PAH concentration (∑PAHs) ranged from 4.49 to 163.66 ng/g dry weight (dry w), with 65.98 ± 33.00 (mean ± SD) ng/g dry w. The highest PAH concentrations and total organic carbon were observed in areas with fine-grained sediments in the Bohai Sea (BS), Yellow Sea (YS), and coastal East China Sea (ECS), indicating the prominent influence of regional hydrodynamics and sediment properties. The dominant PAH congener in BS and YS was BbF, whereas coastal ECS was Phe. The heterogeneity of PAH sources implies that terrestrial PAH input and shelf mud deposition have crucial roles in the source–sink processes of PAHs in a strongly human-influenced marginal sea.

Aliphatic and polycyclic aromatic hydrocarbons in surface sediments as a tool for the assessment of the contamination status of mangrove forests in Rio de Janeiro (Brazil)

The distribution of aliphatic and polycyclic aromatic hydrocarbons (PAHs) in surface sediments from mangrove forests of the Rio de Janeiro State was investigated. Ten sampling stations were selected in the mangroves of Sepetiba Bay and the Jacarepaguá Lagoon Complex (JLC), which are areas affected by multiple human activities. The total aliphatic hydrocarbons concentrations showed marked variation between samples (27–407 μg g−1), mostly related to the total organic carbon contents. The total PAHs concentration ranged between 38 and 792 ng g−1. Diagnostic indices and statistical analysis showed that the mangrove forests can be divided into three groups: the western portion of Sepetiba Bay with the lowest level of contamination; the inner portion of the bay with the most intense presence of local sources of contamination, especially of pyrolytic character; and the JLC with a greater accumulation of hydrocarbons, mainly derived from petroleum combustion, resultant from the intense urbanization.

Distribution, sources and risk assessment of polycyclic aromatic hydrocarbons in surface sediments from the Yellow Sea coast, China

To study the distribution, sources, ecological/health risks, and the impact of regional economic variations on polycyclic aromatic hydrocarbons (PAHs) contaminations along the coast of the Yellow Sea in China, sediments from a broad coastal coverage were collected and analyzed. The total contents of 16 priority PAHs varied between 1.4 and 1675.9 ng/g except in the site of H18 (3191.4 ng/g) adjacent to Qingdao City, with an average value of 295.7 ng/g. PAH pollution along the coast presented a distinctive geographical feature, which was closely linked to local human activities, such as Rongcheng with industrial zones and aquacultural areas, and Yancheng Wetland with developed aquaculture. The source analysis results indicated that PAHs were mainly from pyrolytic sources, with smaller contributions from petroleum spills and combustion. Risk assessment suggested that PAH pollution along the Yellow Sea coast showed negligible biological risks and health risks in most areas.

Occurrence and sources of microplastics and polycyclic aromatic hydrocarbons in surface sediments of Svalbard, Arctic.

Due to the distinct environment condition and geographic location, Svalbard has been recognized as a potential pollution reservoir in the Arctic. In this study, 8 surface sediment samples were collected from two fjords in Svalbard (Kongsfjorden and Rijpfjorden) in 2017, and they were searched for microplastics and polycyclic aromatic hydrocarbons (PAHs). PAHs were also investigated in 10 soil samples of Ny-Ålesund for local anthropogenic source analysis. The level of microplastics and other anthropogenic particles ranged from not detected (ND) to 4.936 particles/kg dry weight (DW). Fiber was the only shape of the microplastics found and three polymers (polyester, rayon and cellulose) were detected, which suggested that fisheries-related debris and textile materials were possible sources of microplastics and anthropogenic particles. For PAHs, the level of ∑26PAH was 9.2ng/g to 67.1ng/g (DW), and were dominated by lnP and BghiP, indicating petroleum combustion source. Further analysis revealed that traffic emissions from cars and diesel combustion from a local power plant were major sources of PAHs in soils of Ny-Alesund, while traffic emissions from ships were the dominate source of PAHs in sediments of Kongsfjorden and Rijpfjorden. A higher level of PAHs was observed in Ny-Alesund, confirming an anthropogenic input, while transport via ocean currents might contribute to the higher abundance of microplastics in Rijpfjorden. Further research and even long-term observation of pollutants are needed to fully understand the pollution status in polar regions.

Potential sources and toxicity risks of polycyclic aromatic hydrocarbons in surface sediments of commercial ports in Taiwan

The accumulation of pollutants in the semi-enclosed waters of ports has long been a concern. This study assessed the pollution status, sources, and toxicity risks of 16 polycyclic aromatic hydrocarbons (PAHs) in surface sediments of 7 major ports in Taiwan. Total PAHs concentrations in sediments ranged between 8.4 and 572.5 ng/g dw, with an average of 112.4 ± 136.5 ng/g dw. The 3- and 4-ring PAHs (63 %) were the major constituents of PAHs in the sediments. Diagnostic ratios and positive matrix factorization analyses indicated that PAHs in sediments were mainly contributed by biomass combustion (45.0 %), coal combustion (31.5 %), and vehicle emissions and related fossil fuels (23.5 %). The results of ecological risk assessment showed a low–medium risk of PAHs in the sediments outside the port, whereas most of the sediments within the port presented a medium–high risk. An assessment of the possible human health risks indicated that PAHs were present at acceptable levels.

Occurrence, distribution and sources of phthalates and petroleum hydrocarbons in tropical estuarine sediments (Mandovi and Ashtamudi) of western Peninsular India

The present study provides baseline information on the concentration levels, distribution characteristics and pollution sources of environmental contaminants, such as phthalic acid esters (PAEs or phthalates) and petroleum hydrocarbons in surface sediments of the tropical estuaries (Mandovi and Ashtamudi) from western Peninsular India. Total PAEs (∑5PAEs), hopanes, steranes and diasteranes concentrations from Ashtamudi estuary ranged from 7.77 to 1478.2 ng/g, n.d.-363.2 ng/g, n.d.-121.5 ng/g and n.d.-116.6 ng/g, respectively. Likewise, PAEs (∑6PAEs), steranes and diasteranes concentrations from Mandovi estuary ranged from 60.1 to 271.9 ng/g, 2.33–40.1 ng/g and 2.28–23.0 ng/g, respectively. The PAEs comprising di-isobutyl phthalate (DIBP), dibutyl phthalate (DBP), an isomer peak for DBP, di(2-ethylhexyl) phthalate (DEHP), di-isononyl phthalate were dominant in Ashtamudi estuary sediments, while PAEs including diethyl phthalate, DIBP, DBP and its isomer, DEHP, di(2-ethylhexyl) terephthalate were detected in the Mandovi sediment samples. The results of this study show an insignificant correlation of TOC with PAEs, and indicates that the varying spatial distributions of the PAEs in both the estuaries can be the result of discharge sources. The higher concentration of PAE congeners was noticed in Ashtamudi, a Ramsar wetland site, that can be attributed to land-based plastic waste. The petroleum biomarkers were abundantly present in Mandovi estuary due to anthropogenic activities such as boating and spillage from oil tankers. The findings of the present study will serve as a reference point for future investigation of organic contaminants in Indian estuaries, and calls for attention towards implementing effective measures in controlling the pervasion of the PAEs and petroleum biomarkers.

Contribution of atmospheric deposition to halogenated polycyclic aromatic hydrocarbons in surface sediments: A validation study

Surface sediments are both sinks and sources of chlorinated and brominated polycyclic aromatic hydrocarbons (Cl/Br-PAHs) in the environment. It is important to study the source of Cl/Br-PAHs in the surface sediment for controlling the ecological risk of Cl/Br-PAHs. Clues from the previous research suggested that atmospheric deposition may be one of the main sources of Cl/Br-PAHs in sediment. However, due to the lack of matched sediment and atmospheric Cl/Br-PAHs data, the contribution of atmospheric deposition to Cl/Br-PAHs in sediment has not been confirmed. This study investigated the characteristics of 37 Cl/Br-PAHs and validated the contribution of atmospheric sedimentation to Cl/Br-PAHs in sediment by a case study in the surface sediments of the Chaobai River, China. To the best of our knowledge, four Cl-PAHs and eleven Br-PAHs were found in the sediments for the first time. The total concentrations of 18 Cl-PAH species were 76–2301 pg/g, while those of Br-PAHs were 6–238 pg/g. The toxic equivalent quantities (TEQ) of the Cl-PAHs in surface sediments in the water conservation area and in the urban comparison area were 0.73 pg TEQ/g and 2.21 pg TEQ/g, respectively. The TEQ of the Br-PAHs in surface sediments in the water conservation area and in the urban comparison area were 2.85 × 10−2 pg TEQ/g and 6.6 × 10−2 pg TEQ/g, respectively. Based on the characteristics comparison and correlation analysis of Cl/Br-PAHs in both sediment and ambient air, it was initially confirmed the contribution of atmospheric deposition to Cl-PAHs in sediments. However, there was no conclusion of Br-PAHs in sediment similar to Cl-PAHs in sediment. It was inferred that the sources of Br-PAHs in sediment were different from Cl-PAHs in sediment.

Spatial distribution of total petroleum hydrocarbons in surface sediments of Palk Bay, Tamil Nadu, India

Palk Bay is a marine protected area with a sensitive ecosystem like coral reefs, seagrass meadows, and mangroves with rich biodiversity. Observations indicate that these ecosystems are at risk from organic contaminants like petroleum hydrocarbon. In view of this Total Petroleum Hydrocarbons (TPHs) were measured in the surface sediments from the Palk Bay. Sediment samples were extracted in n- hexane and quantified using a fluorescence spectrophotometer. The concentrations of TPH varied from 0.78 ± 0.28 to 2.70 ± 0.84 μg/g (wet wt.) and were relatively higher in southern region than the northern. Higher TPH levels at the Bay are attributed to the anthropogenic activities and hydrodynamic characteristics. Analysis of sediment texture and organic carbon can provide insights into the distribution of TPH. Significant correlation was found between the sediment texture with TPHs and TOC. The average proportions of sediment grain sizes were 88.39 ± 3.92% of sand, 70.54 ± 2.24% of loamy sand, 62.22 ± 3.76% of sandy loam, and 29.58 ± 5.59% silt loam. Silt and clay of sediment have more capacity to hold the TPH because of their particle size. This is in consonance with the observed TOC levels in the range of 0.11 ± 0.05% and 2.78 ± 1.12% (dry weight). TPH concentrations are observed within the permissible limits and the data may serve as baseline information for identifying pristine coastal ecosystems like Palk Bay. • Total Petroleum Hydrocarbons in sediments of Palk Bay is reported for the first time. • This study found high TPHs at northern and southern mouth of the Palk Bay. • Distribution of TPHs depends on hydrographic and sediment characteristics. • TPH concentrations are observed within the permissible limits. • Monitoring is suggested for evaluation and management of TPHs.

Determination of aliphatic hydrocarbons in surface sediments of Mangueira Lagoon (RS—Brazil)

Determination of aliphatic hydrocarbons in surface sediments of Mangueira Lagoon (RS—Brazil)

Validation of an analytical technique, distribution, and risk assessment of aliphatic and polycyclic aromatic hydrocarbons in surface sediments of the coastal and selected estuaries of Sarawak

This study explains a validation of an analytical technique, monitoring, and risk evaluation of hydrocarbons in surface sediments of the coastal and selected estuaries of Sarawak, Malaysia. The performance of an analytical methodology was validated for the evaluation of hydrocarbons in coastal and estuaries sediment samples. After the clean-up and separation process, GC-FID and GC-MS were used to quantify aliphatic and polycyclic aromatic hydrocarbon extracts, respectively. The suggested methodology is able to measure aliphatic and polycyclic aromatic hydrocarbons in samples at lower concentrations for example 10 ng/g. The precision of the technique was satisfactory as compared to 15% for most of the analytes. This method gives information concerning the distribution and characteristics of hydrocarbon contaminants in the coastal environment. In regard to monitoring and risk assessment, total n-alkane concentrations (C10–C33) varied from 96.63 to 367.28 ng/g dw. The lowest and highest n-alkane content is observed at Santubong estuary (CZ10) and the coastal site CZ2, respectively. Simultaneously, the contents of ∑PAHs varied from 12.54 to 21.20 ng/g dw. The highest ∑PAH content is reported in the sediments of coastal site CZ8 (21.20 ng/g dw), whereas the lowest content is recorded in the sediments of coastal site CZ3 (12.54 ng/g dw). The outcome of the risk assessment suggested that there is no risk in all the studied locations. The findings from this study will help to understand the sources and possible risks of hydrocarbons in the coastal and estuary settings, and provide information for safeguarding human health and aquatic bodies in the studied area.

Evaluation of Aliphatic Hydrocarbons in Surface Sediments of Lagoa Mirim (RS, Brazil).

In this study, the hydrocarbons (HCs) levels in sediments from Lagoa Mirim, situated in the south of Brazil, were verified. The methodology brought together stages of pre-sonification, soxhlet extraction, and determination by gas chromatography coupled with mass spectrometry (GC/MS). Ten sample points were evaluated where ∑n-alkanes varied between 1.46µg kg-1 ± 4.0% and 10.10µg kg-1 ± 17.6%. Diagnostic indexes were calculated, being: Carbon Preferential Index (CPI), terrestrial/aquatic ratio (TAR), unresolved complex mixture (UCM), UCM/∑n-alkanes ratio, and n-alkane ratio with Low molecular weight hydrocarbon and High molecular weight hydrocarbons (HMW/LMW). In general, the results of this study indicate a low anthropogenic impact in the environment.

Pollution status of polycyclic aromatic hydrocarbons in surface sediments off the Jiangsu coastal zone, East China: A case study of Rudong

In the current study, 16 congeners of PAHs were measured in 32 surface sediment samples to determine their pollution status in the Jiangsu coastal zone, East China. The total concentrations of the 16 PAHs ranged from 2.2 to 46.6 ng g−1 with an average of 8.36 ng g−1 in surface sediments and were significantly lower than those of PAHs in other coastal areas of China. The spatial distribution of PAHs revealed an increasing trend from nearshore to offshore, controlled by the regional sedimentary dynamic environment. Diagnostic ratios and positive matrix factorization demonstrated that petroleum, industries, biomass and coal combustion, and marine and vehicular traffic sources contributed to 28.9%, 25.5%, 24.7%, and 20.9% of the total PAHs, respectively. Risk assessment suggested that the carcinogenic risks were <1 × 10−4 for all age groups in the area, indicating that long-term seafood consumption does not pose a significant cancer risk in this area.

Contribution of Atmospheric Deposition to Halogenated Polycyclic Aromatic Hydrocarbons in Surface Sediments: A Validation Study

Contribution of Atmospheric Deposition to Halogenated Polycyclic Aromatic Hydrocarbons in Surface Sediments: A Validation Study

Parent and alkylated polycyclic aromatic hydrocarbons in surface sediments of mangrove wetlands across Taiwan Strait, China: Characteristics, sources and ecological risk assessment

The characteristics, distributions and sources of parent polycyclic aromatic hydrocarbons (PAHs) and alkyl-PAHs (A-PAHs) as well as their ecological risk were explored in six mangrove wetlands across the Taiwan Strait, China. A-PAHs fingerprinting information, combined with PAHs diagnostic ratios and a positive matrix factorization model, were used to identify the sources of PAHs in the mangrove wetland surface sediment samples. The results showed that the total concentration of the 36 PAHs in the sediment samples varied from 186.2 to 2469.2 ng⸱g−1. Furthermore, the total concentration of PAHs would be underestimated about 37.1%–80.6% when only the concentrations of 16 priority PAHs were examined in the sediment samples. Coal combustion (32.7%) and petroleum combustion (24.6%) were identified as important contributing sources in the Yunxiao, Fugong, and Quanzhou mangrove wetlands, whereas the main source was mainly petroleum combustion (49.1%) in the Guandu, Zhuwei and Waziwei mangrove wetlands. In addition, the guidelines for assessing the ecological risk of individual A-PAHs need to be developed due to lack of criteria for most individual A-PAHs.

Spatiotemporal distribution and source variations of hydrocarbons in surface sediments from the Pearl River Estuary, Southern China

Variations in hydrocarbon composition and concentration are essential for the assessment of its source and environmental health in estuarine environments. This study aims to reveal the spatial and temporal distribution of multiple hydrocarbons in surface sediments of the Pearl River Estuary, and to further determine various sources of these hydrocarbons. Surface sediments were taken monthly from four sites along a spatial transect from the Pearl River Estuary in a whole year by using a gravitational bottom sampler. A series of bulk parameters including the grain size, total organic carbon content, and total nitrogen content were measured. Hydrocarbons in sediments were extracted and analyzed by the gas chromatography-mass spectrometry. The abundances of higher plants and phytoplankton-derived n-alkanes, petrogenically derived pristane, phytane, hopanes, and steranes with geological configuration, and anthropogenically derived hydrocarbons, including linear alkylbenzenes and polycyclic aromatic hydrocarbons all showed decreasing trends towards the coastal ocean. In contrast, the diatom-derived C25 highly branched isoprenoids increased towards saline sites. Monthly fluctuations of aliphatic and aromatic hydrocarbons at the estuarine mouth were smaller than the upstream freshwater sites, where high monthly variation (up to fivefold) was observed for most of the hydrocarbons detected. This study showed substantial monthly and spatial variations of hydrocarbons in the surface sediments of the Pearl River Estuary. Distribution and composition of sedimentary hydrocarbons indicate mainly anthropogenic inputs (e.g., petroleum residues and synthetic detergents) and terrestrially higher plants, followed by aquatic inputs.

Polycyclic aromatic hydrocarbons in surface sediments of the Aegean Sea (eastern Mediterranean Sea)

In this study, we provide baseline data on the composition, major sources and mechanisms driving the distribution of polycyclic aromatic hydrocarbons (PAHs) mixtures in surficial sediments collected from 43 offshore and open/deep sea locations across the north, central and south Aegean Sea. The determined total concentrations of the considered PAH compounds were generally low, comparable to those reported in relatively non-polluted coastal and open/deep Mediterranean marine sites. Their molecular profile and diagnostic indices reveal mixed contributions from both pyrolytic and petrogenic sources across the study area. Organic carbon exerts an important control on the transport and ultimate accumulation of PAHs, however, the presented results highlight a significant variability in sedimentary PAHs concentrations and compositional patterns within the studied Aegean Sea sub-regions. This could be likely attributed to a combination of distinct hydrological and biogeochemical characteristics, surface and near bottom water mass circulation patterns and the relative importance of PAH sources.

Polycyclic Aromatic Hydrocarbons in Surface Sediments and Fish Tissues Collected from a Protected Lagoon Region.

Polycyclic aromatic hydrocarbons (PAHs) were detected and quantified in sediment and edible fish (Megalops atlanticus) from Caleta lagoon (Lagoon of Terminos, Mexico) in order to assess their potential health impact on consumers. Sum PAH concentrations in sediment and fish muscle tissues were dominated by high molecular weight PAH compound (46.4%-93.1%) relative to low molecular weight compounds (6.9%-42.9%). Contamination was associated with local industrial activities and urbanization. The effective range low (ERL: 4022ngg-1) value were lower suggested adverse biological effect would be rarely observed. While the analysis of PAHs in muscle of M. atlanticus suggests a minimum impact to consumers according to the permitted limits of dibenzo (a, h) anthracene (10ngg-1) and benzo [a] pyrene (0.1-1.2μgkg-1). It is advisable to propose environmental strategies to mitigate future environmental damage in the ecosystem.