Weight Polycyclic Aromatic Hydrocarbons Research Articles

Assessment of PAHs accumulation in Donax trunculus (Linnaeus, 1758) (Bivalvia, Donacidae) from the Bulgarian Black Sea Coast

Anthropogenic pollution of marine ecosystems is one of the main sources of polycyclic aromatic hydrocarbons (PAHs). Marine bivalves are often used as bioindicators of environmental pollution due to their wide distribution and capability of xenobiotic bioaccumulation. The aim of the present study was to assess the presence of PAHs in soft tissues of wedge clams Donax trunculus (Linnaeus, 1758), collected from sublittoral sandy habitats at different locations off the Bulgarian Black Sea coast. Wedge clams from the different locations showed variations in the content of accumulated PAHs’ compounds. The concentrations of PAHs were measured by gas chromatography system with mass spectrometry detection. The total PAHs content (sum of 13 PAHs’ compounds) measured was in the range from 5.59 to 50.50 ng/g wet weight and was comparable with other European studies. The compounds phenanthrene and fluorene were most abundant in all analyzed samples. The results showed that low molecular weight (LMW) PAHs (2 and 3 aromatic rings) were predominant, accounting for 91% of the total PAHs levels, while high molecular weight (HMW) PAHs (4–5- and 6- rings) presence was 8.9% on average. The ratio LMW/HMWPAHs was higher than one, suggesting predominant pollution of petrogenic origin. The concentrations of benzo (a)pyrene did not exceed the limit set in EC Regulation although it was detected in 20% of the analyzed samples. In conclusion, maximum overall PAHs content was found in clams from Arkutino, while minimum PAHs content was present in samples from Elenite. The Sum PAH4 (sum of four polycyclic aromatic hydrocarbons: benzo[a]pyrene, chrisene, benzo[a]anthracene, and benzo[b]fluoranthene) in the wedge clams for all localities studied was below legislation limits. Data from the present research can be used for assessing pollution levels in the marine environment and also risk of human exposure to PAHs using D. trunculus as bioindicator species.

Distribution and Source Apportionment of Polycyclic Aromatic Hydrocarbons in Soils at Different Distances and Depths around Three Power Plants in Bijie, Guizhou Province

In this study, 16 polycyclic aromatic hydrocarbons (PAHs) optimally controlled by the U.S. Environmental Protection Agency (EPA) were investigated. Three representative coal-fired power plants were selected as the research areas in Bijie, Guizhou Province, and 24 soil samples were collected totally from power plants at different depths and at different distances from the point pollution sources (plants). The physicochemical properties and microbial characteristics of the soil from the three power plants were also studied. The results showed that 16 PAHs were detected in all soils of the three power plants, with total concentrations ranging from 0.2 to 12.2 mg kg−1, and that PAHs in the soils were mainly 2, 3 rings with percentages ranging from 42% to 82%. The proportions of low molecular weight (LMW) PAHs were higher near the contaminated plants. Moreover, since they were easily dispersed further away with atmospheric transfer, the proportions of lighter LMW PAHs were also higher far from the point source, while the proportions of heavier high molecular weight (HMW) PAHs were higher at some distance from the point source. In addition, the distribution patterns of PAHs in the soil at different depths were slightly different because the microbial activity in the surface soil at each sampling site was greater than that in the deeper soil, and the leaching behavior of each compound was different. Finally, based on the principal component analysis (PCA) method, coal combustion is not the only source of PAHs in soils from power plants, and vehicle emissions cannot be negligible.

Optimization and Interaction Analysis of Bacterial and Fungal Growth in the Presence of Benzo(A) Pyrene in Wastewater

In wastewater treatment plant, an aerobic approach is adopted in the system which utilize the ability of bacteria in the wastewater to reduce biochemical oxygen demand (BOD) and other organic pollutants. High molecular weight of polycyclic aromatic hydrocarbons (HMW-PAHs) are type of organic persistence and insoluble pollutants which hard to be removed from wastewater by bacteria. Owing to the HMW-PAHs tolerant characteristic and abundancy of fungi in wastewater, the bacteria and fungi interaction is anticipated to degrade the HMW-PAHs in wastewater. Thus, this study is carried out as a preliminary study to understand the interaction by optimized the bacterial and fungal growth in the presence of benzo[a]pyrene (BaP). Bacteria and fungi used in this study were Sphingobacterium spiritovorum and Aspergillus brasiliensis ATCC 16404. The response surface methodology (RSM) in Design-Expert® Version 7.0.0 software was used to analysed two factors which are pH and temperature on the bacterial and fungal growth. The growth of bacteria and fungi in co-culture and existence of BaP also been studied. The optimization study showed the growth of S. spiritovorum and A. brasiliensis was optimized at pH 6.2, temperature of 32 °C, and pH 6.5 and temperature of 33 °C, respectively. Synergy interaction was observed in the co-culture condition and with the existence of BaP. The present study provides beneficial information about the bacteria and fungi interaction which has the potential to be applied in the wastewater treatment plant.

Identification of polycyclic aromatic hydrocarbons in roadside leaves (Ficus benghalensis) as a measure of air pollution in a semi arid region of northern, Indian city-A smart city

Abstract In this work, the semi-arid region of northern India was selected to observe the contamination levels, scattering pattern, seasonal distribution, the ratio of low and high molecular density carcinogenic PAHs (Polycyclic Aromatic Hydrocarbons) in the roadside plants (Ficus benghalensis). Total 48 samples [DAV College Jalandhar (inside city) as well as CT Group of Institutions Jalandhar (outside city)] were collected during the year 2017 (within four varying seasons). In order to understand the distribution pattern of PAHs we applied, Principal Component Analysis (PCA) and Cluster Analysis with Multivariate Linear Regression (MLR). The major resources of PAHs on roadside plants were the source of Petrogenic and Pyrogenic. Involvements of Coal Combustion Products (CCPs), automobiles exhaust emission and trickles of lubricate products (Petrogenic) were the key contributors with 36%, 36% and 28% using PCA/MLR, respectively. The mean concentration of total (low and high molecular weight) PAHs (Inside city) were 5.77 and 6.99 ng/m3 (1:1.44) whereas at outskirts of the city was 4.59 and 6.99 ng/m3 (1:1.93), respectively. Total PAHs mean concentration of PAHs (Inside city) was 105.81ng/m3, whereas in the outskirts of the city it was 97.34 ng/m, 3 respectively. The results of total PAHs concentrations (Inside city), indicated that the 4-ringed carcinogenic PAHs were at alarmingly surpassing concentrations (i.e., 30.35 ng/m3), whereas, at city outskirts 4, 5, and 6-ringed hydrocarbons were found in elevated concentration (i.e., 28.49, 25.59, and 23.46 ng/m3). The Two-tailed t-test, ring distribution pattern and toxic equivalency factor were applied for the statistics significance of results.

The use of polycyclic aromatic in the assessment of marine life and the impact on petroleum pollution in the Suez Gulf, Egypt

This study represents the concentrations of 16 PAHs in a commercial aquatic species Sauridaund squamis; Euthynnus affinis; Rhabdosargus haffara; Argyrops Spinifer; Nemipterus Japonicus, Oreochromis Niloticus; Trachurus Indicus; Peneus Japonicas; Scomber Japonicus; and Pomadasys Stridens, which were collected from the coastal area of the Suez Gulf waters. The analyses of polycyclic aromatic hydrocarbons (PAHs) were determined using HPLC to identify the sources of PAHs. The results revealed that low molecular weight of PAHs were more than high molecular weight in aquatic species, Benzo (a)Anthracene/(Benzo (a) Anthracene + Chrysene) BaA/(BaA + Chr), Indeno (1,2,3-cd) pyrene/(Indeno (1,2,3-cd) pyrene + Benzo (ghi) perylene) IP/(IP + BP) and Fluoranthene/Pyrene (Fl/Pyr), they reflected that the PAHs sources in aquatic species are petrogenic as a main sources, pyrogenic sources. The study area was generally contaminated with hydrocarbons and continuous consumption of food from this area may pose public health hazards.

Spatio-Temporal Variations in the PAH Concentrations in the Soil Samples Collected from Functional Brick Kilns Locations in Balochistan, Pakistan

The current study aimed to envisage the spatial and seasonal distribution of the six polycyclic aromatic hydrocarbons (PAHs) in the soil samples collected in the proximity of the brick kilns in Balochistan, Pakistan. Soil samples were collected in four directions with the increasing distance of 100, 300 and 500 m away from each brick kiln at all study sites. The concentration of the PAHs was determined through high-performance liquid chromatography (HPLC). The results of the current study report that all six PAH compounds were detected in the soil samples and the concentration of the studied PAHs varied with increasing distance from the source and with directions. Total PAHs (∑PAHs) concentration at study sites ranged from 2.74 to 4.51 µg/g and 1.05 to 1.13 µg/g in summer and winter seasons, respectively. The maximum concentrations of the PAHs were found in the summer as compared to the PAHs detected in winter. The soil was dominated by low molecular weight (LMW) PAH compounds in the summer whereas, in the winter soil was dominated by high molecular weight (HMW) PAH compounds. The concentration levels of all detected PAHs also varied among the studied sites. Carcinogenic potency of PAHs in studied samples was less than 1 except the soil samples from Mastung. No correlation was noticed between physiochemical properties and ∑PAHs. It is recommended that the soil near the brick kilns be regularly monitored for the presence of PAHs due to their high potential of carcinogenicity.

Soil organic matter composition as a factor affecting the accumulation of polycyclic aromatic hydrocarbons

PurposeThe objective of this study was to evaluate the mutual relations between the soil organic matter (SOM) fractions: fulvic acids (FA), humic acids (HA), humins (HN), black carbon (BC) and the polycyclic aromatic hydrocarbons (PAH) accumulation level in agricultural soils influenced by historical and actual anthropopressure. The research allowed to indicate which fractions of SOM are the major sequestration sinks for PAHs after they are naturally introduced into the soil.Materials and methodsSoil samples were collected from the upper layer of agricultural soils (n = 41), and basic physicochemical properties (pHKCl, total carbon, total nitrogen and clay content) were determined. The SOM was characterised by the total organic carbon content and humic substances, including HA, FA and HN, determined by an adapted method recommended by the International Humic Substances Society. The extracts of HA and FA were analysed for carbon content using a liquid CN analyser, while HN constituted the soil carbon in the residue after FA and HA extraction. The content of BC was analysed by dry combustion at 375 °C for 24 h (CTO375); the remaining carbon was determined via combustion in an elemental analyser.Results and discussionIn all soils, significant positive relations between PAH concentrations and TOC content (r = 0.73, p < 0.001) as well as HN (r = 0.71, p < 0.001) and BC (r = 0.86, p < 0.001) were noted. Relations among PAHs, HN and BC were statistically significant only in soils with TOC content ≥ 12 g kg−1, while they were not observed for soils with TOC content < 12 g kg−1. The links between HN and PAHs were stronger for low-molecular (two and three rings)-weight PAHs (r = 0.77, p < 0.05) than for high-molecular (≥ four rings) PAHs (r = 0.68, p < 0.05). Contrary to HN, the BC faction showed higher correlations with high-molecular-weight PAHs (r = 0.92, p < 0.001). FA and HA showed no significant relationship with hydrocarbons.ConclusionsDifferent SOM fractions might possess divergent binding capabilities and dissimilar binding strengths to PAHs. The different proportions and sorption capacities of BC and HN in relation to PAHs of different molecular weight are the result of varying structure, i.e. polar and non-polar functionalities in sorption domains and pore-size structures of these fractions. The high correlation between BC and higher-molecular PAHs may be a result of their co-emission, while the stronger relationships between HN and lower-molecular PAHs are directly related to their higher mobility and easier diffusion to stable SOM fractions.

Selenium alleviates phytotoxicity of phenanthrene and pyrene in Alternanthera Philoxeroides

To investigate if selenium can alleviate phytotoxicity of phenanthrene and pyrene, two high molecular weight (HMW) PAHs (polycyclic aromatic hydrocarbons) in Alternanthera philoxeroides are considered. A 60-day pot-culture experiment was carried out to assess the effects of selenium (0.5 mg Se·kg−1 soil) on A. philoxeroides exposed to two PAH pollutants, pyrene (PYR) and phenanthrene (PHE), at levels of 10, 100, and 1000 mg·kg−1. The test index included growth, chlorophyl, gas exchange and chlorophyl fluorescence parameters, and indicators of oxidative stress (H2O2 and malondialdehyde MDA). The response of plants to PAH exposure was concentration dependent; indicators of plant health declined, while indicators of plant stress rose. The maximum values of H2O2 and MDA were recorded at 1000 mg·kg−1 PYR, followed by 1000 mg·kg−1 PHE. However, application of Se (0.5 mg·kg−1) to the soil significantly decreased the phytotoxic response to PAH exposure. This study demonstrated that Se increases the tolerance of A. philoxeroides to PYR and PHE, improving the feasibility of phytoremediating high level PAH contamination and expediting ecological restoration.

Phylogeny and polycyclic aromatic hydrocarbons degradation potential of bacteria isolated from crude oil-contaminated site

ABSTRACTThis study employed the use of 16S rRNA gene sequence analysis to identify three of four native bacterial strains isolated from crude oil-contaminated site in Poza Rica, Veracruz, Mexico. The identified bacteria were Ochrobactrum intermedium, Pandoraea pnomenusa and Ochrobactrum sp., but SA2-09 strain was not identified. The ability of the isolates to degrade polycyclic aromatic hydrocarbons (PAHs) was evaluated at 31.61 and 54.52 mg/kg PAHs in soil, when used as crude oil in soil microcosm during 80 days of incubation at 30°C. The results demonstrated that O. intermedium biodegraded many PAHs, including the high molecular weight (HMW) PAHs fluoranthene (100% equivalent 0.24 mg/kg), benzo [b] fluoranthene (81.8% equal 0.18 mg/kg), Benzo[a]pyrene (87.0%, 0.20 mg/kg) and Benzo[g,h,i]perylene (52.7%, 0.39 mg/kg). P. pnomenusa had a degradation profile of HMW PAHs, which was similar to O. intermedium, while Ochrobactrum sp. and the strain SA-09 exhibited lower degradation rates of HMW.

Diurnal Variability of Persistent Organic Pollutants in the Atmosphere over the Remote Southern Atlantic Ocean

A diel (24-h) cycle with daytime atmospheric concentrations higher than nighttime concentrations by a factor of 1.5–3 was observed for several low molecular weight polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in remote areas of the tropical South Atlantic during a cruise in October–November 2005. In contrast, high molecular weight PCBs and PAHs did not display diurnal variability. A model which has successfully explained diel variability of persistent organic pollutants (POPs) over land could not reproduce the observed diel cycle by considering variability in temperature, atmospheric OH radical concentrations, atmospheric boundary layer height and wind speed as causal factors. We used the model to conduct two bounding scenarios to explore the possibility that phytoplankton biomass turn-over in the surface ocean drives the observed variability in air concentrations. The model could only qualitatively reproduce the field observations of diel variability for low chlorinated PCB congeners when the ocean acts as a source of pollutants to the atmosphere, and when variability in biomass drives variability in the capacity of the surface ocean.

Testing the Efficiency of a Stormwater Runoff Treatment Structure with Anthropogenic Tracers

The stormwater treatment efficiency of a swirl reactor—a common best management practice—was determined by evaluating the fate and transport of two classes of primarily anthropogenic contaminants: polycyclic aromatic hydrocarbons (PAH) and heavy metals (copper, zinc). In addition, total dissolved and total suspended solid (TDS and TSS, respectively) treatment was evaluated. For this study, treatment efficiency was defined as the percent difference between the swirl reactor influent and effluent concentration measured during one particular storm event. The results of this study indicate that TSS was removed efficiently (between 64.7 percent and 85 percent). However, possible resuspension of sediments during high flow conditions was observed. The swirl reactor did not remove TDS. Treatment of copper was 13 percent efficient, whereas zinc was not attenuated. The maximum dissolved PAH (= total of 10 PAH compounds) treatment efficiency was 16.8 percent initially, but decreased to 8.4 percent by the end of the storm (average: 13.1 percent). Significant differences in removal effectiveness existed between dissolved low–molecular weight (LMW) and high–molecular weight (HMW) PAHs. While LMW PAH removal was moderately effective, HMW PAH concentration was not affected by the swirl reactor. About 19.9 percent of PAHs associated with sediments that settle were removed. Similar to dissolved PAH removal, LMW PAH-loaded sediment effectively settled out of the wastewater stream, whereas HMW PAHs were found to migrate through the reactor unhindered.

Distinguishing PAH Background and MGP Residues in Sediments of a Freshwater Creek

Polycyclic aromatic hydrocarbons (PAHs) in the environment have origins in various natural and anthropogenic sources. Pyrogenic tars (e.g., coal tar) are rich in PAHs, which are therefore typical constituents of concern at former manufactured gas plant (MGP) sites. Delineating the extent of PAHs in sediments is a common component of many former MGP remedial investigations. Because of the compositional similarity of weathered/degraded coal tar residues to combustion-related PAHs that comprise typical urban background, it can be difficult to determine the local PAH background contribution in sediments near MGP sites. This article presents an investigation of Mill Race Creek, a freshwater creek that flows adjacent to the Oneonta, New York former MGP. From the delineation sampling, elevated PAH concentrations were measured in “background” areas upstream of any suspected MGP releases. PAH fingerprinting revealed three primary PAH sources in creek sediments: low molecular weight (LMW), 2- and 3-ring PAHs from background petroleum sources; high molecular weight (HMW), 4- to 6-ring PAHs from site-related sources; and HMW PAHs from background sources. The results of this investigation demonstrated that site-related PAH residues were primarily localized in the subsurface of a few sediment deposits adjacent to the former MGP. Sediments containing site-related PAHs were generally buried underneath a surficial (6 in) layer of sediments with total priority pollutant PAH concentrations (55.0 ± 48.8 mg/kg) that were almost entirely attributable to local background sources. In the context of a remedial investigation, contributions from uncontrolled background PAHs may limit the practicable feasibility of some remedial options.

Exposure of juvenile chinook and chum salmon to chemical contaminants in the Hylebos Waterway of Commencement Bay, Tacoma, Washington

The Hylebos Waterway is an industrialized waterway ofCommencement Bay, Tacoma, Washington, that is severelycontaminated with aromatic and chlorinatedhydrocarbons in the sediment. Juvenile chinook (Oncorhynchus keta) and chum salmon (O.tshawytscha) inhabit this waterway for a few days orweeks during their outmigration from freshwaterstreams to saltwater. The purpose of thisinvestigation was to determine to what degree juvenilechum and chinook salmon captured from the HylebosWaterway might bioaccumulate organic contaminants. These levels of exposure will be compared to previousstudies where such exposures have been linked tobiological dysfunction in juvenile salmon. Theresults showed that juvenile chum and chinook salmonfrom the Hylebos Waterway take up a wide range ofchemical contaminants, compared to fish fromhatcheries or reference estuaries. These contaminantsinclude high and low molecular weight polycyclicaromatic hydrocarbons (PAHs), polychlorinatedbiphenyls (PCBs, including the toxic congeners 105 and118), hexachlorobutadiene (HCBD), hexachlorobenzene(HCB), DDTs, heptachlor, and several pesticides. Immunohistochemical examination of the gill and gut injuvenile chum salmon from the Hylebos Waterway showedthe induction of the P450 metabolizing enzyme. Moreover, concentrations of contaminants in juvenilechinook and chum salmon from the Hylebos Waterway arecomparable to levels previously shown to be associatedwith biological injury in juvenile chinook salmon,such as impaired growth, suppression of immunefunction as demonstrated by reduced B cell function,and increased mortality following pathogen exposure.

Dry deposition of pahs in the ambient air of central Taiwan

The atmospheric polycyclic aromatic hydrocarbons (PAHs) in ambient air of central Taiwan at Wu‐Chi, Sha‐Lu, Ta‐Duh, and the Expressway Interchange of Taichung city were studied. Dry deposition and air sampling were undertaken simultaneously with several dry deposition plates and PS‐1 samplers from May 1995 to March 1996. Twenty‐one individual PAHs were analyzed primarily with a gas chromatography/mass spectrometer (GC/MS). In general, the lower molecular weight (LMW) PAHs, being primarily in the gas phase, have lower dry deposition velocities; while the higher molecular weight (HMW) PAHs, which are mainly associated with particulates, have higher dry deposition velocities. The mean dry deposition velocities for LMW PAHs — Nap, AcPy and Acp — are 0.054, 0.040 and 0.15 cm sec‐1, respectively. However, the dry deposition velocities of 10 HMW PAHs, including BbF, BkF, BeP, BaP, PER, IND, DBA, BbC, BghiP and COR, are all at the same level but up to 2 orders of magnitude higher than those of LMW PAHs. Because of the “synergism”; of higher fraction in particle‐phase and higher deposition velocity, less than 0.8% of the HMW PAH mass in the dry deposition flux is contributed by the gas phase.

Formation and Determination of Perinaphthenyl Radical and PCAH in Combustion Processes

Abstract The concentration profiles of polycyclic aromatic hydrocarbons (PCAH) and perinaphthenyl radical along a vertical flow reactor have been determined for fuel rich premixed flames of n-heptane with small fractions of other hydrocarbons, methanol, and nitrogen oxide. It has been found that there is a strict relation between the concentrations of the higher molecular weight PCAH, which are the main components of soluble fraction of soot, and the perinaphthenyl radical. The aromatic ring of the fuel supplying the reactor plays the most significant role in the formation of PCAH and perinaphthenyl radical. Furthermore their concentrations increase passing from benzene toluene and, lastly, to mesitylene, because the energy of the C(arom)-C(alif) bond is lower than that of the C(arom)-C(arom) bond. The promoting action of methanol, when added to benzene, in the formation of PCAH and perinaphthenyl radical could be explained by the increased presence of CH3- radicals, which, can overcome the inhibiting act...