Kinds Of Polycyclic Aromatic Hydrocarbons Research Articles

The application of laser‑induced fluorescence in oil spill detection.

Over the past two decades, oil spills have been one of the most serious ecological disasters, causing massive damage to the aquatic and terrestrial ecosystems as well as the socio-economy. In view of this situation, several methods have been developed and utilized to analyze oil samples. Among these methods, laser-induced fluorescence (LIF) technology has been widely used in oil spill detection due to its classification method, which is based on the fluorescence characteristics of chemical material in oil. This review systematically summarized the LIF technology from the perspective of excitation wavelength selection and the application of traditional and novel machine learning algorithms to fluorescence spectrum processing, both of which are critical for qualitative and quantitative analysis of oil spills. It can be seen that an appropriate excitation wavelength is indispensable for spectral discrimination due to different kinds of polycyclic aromatic hydrocarbons' (PAHs) compounds in petroleum products. By summarizing some articles related to LIF technology, we discuss the influence of the excitation wavelength on the accuracy of the oil spill detection model and proposed several suggestions on the selection of excitation wavelength. In addition, we introduced some traditional and novel machine learning (ML) algorithms and discussed the strengths and weaknesses of these algorithms and their applicable scenarios. With an appropriate excitation wavelength and data processing algorithm, it is believed that laser-induced fluorescence technology will become an efficient technique for real-time detection and analysis of oil spills.

Characteristic Variation of Particulate Matter-Bound Polycyclic Aromatic Hydrocarbons (PAHs) during Asian Dust Events, Based on Observations at a Japanese Background Site, Wajima, from 2010 to 2021

Asian dust (AD) events and total suspended particles (TSPs) were observed at the Kanazawa University Wajima Air Monitoring Station (KUWAMS), a Japanese background site, during the East Asian winter monsoon periods (from November to May of the following year) from 2010 to 2021. Nine kinds of polycyclic aromatic hydrocarbons (PAHs) were determined in each TSP sample. In this study, a total of 54 AD events were observed. According to the different pathways of long-range transportation, AD events were divided into AD-high events (transported at higher altitudes, approximately 4000 m) and AD-low events (transported at lower altitudes, approximately 2500 m). The TSP concentrations increased sharply in the AD events and were higher in the AD-high events (39.8 ± 19.5 μg/m3) than in the AD-low events (23.5 ± 10.5 μg/m3). AD did not have a significant effect on the ΣPAHs characteristic variation, as ΣPAHs (ΣPAHs = fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, benzo[ghi]perylene, and indeno [1,2,3-cd]pyrene) concentrations in non-AD periods, AD-high events, and AD-low events were 543 ± 374, 404 ± 221, and 436 ± 265 pg/m3, respectively. The PAH compositions were also consistent. As a result, the TSP concentration was affected by the input air mass transported at higher altitudes from the desert region while the PAH concentration was impacted by the air mass at lower altitudes, which carried the PAHs emitted from fossil fuels and biomass combustion in northeastern China. Moreover, the health risks of PAHs were calculated with the inhalation lifetime cancer risk, which ranged from 10−6 to 10−5 ng/m3, indicating a potential carcinogenic risk at the KUWAMS during the East Asian winter monsoon periods.

The Preparation of Covalent Bonding COF-TpBD Coating in Arrayed Nanopores of Stainless Steel Fiber for Solid-Phase Microextraction of Polycyclic Aromatic Hydrocarbons in Water.

Covalent organic framework (COF)-TpBD was grafted on the arrayed nanopores of stainless steel fiber (SSF) with (3-aminopropyl) triethoxysilane as the cross-linking agent. The prepared SSF bonded with COF-TpBD showed high thermal and chemical stability and excellent repeatability. The prepared SSF bonded with COF-TpBD was also used for the solid-phase microextraction (SPME) of seven kinds of polycyclic aromatic hydrocarbons (PAHs) in actual water samples, followed by gas chromatography with flame ionization detection (GC-FID) determination, which exhibited low limits of detection (LODs), good relative standard deviation (RSD) and high recoveries.

Extremal values of VDB topological indices over F-benzenoids with equal number of edges.

The utilization of molecular structure topological indices is currently a standing operating procedure in the structure-property relations research, especially in QSPR/QSAR study. In the past several year, generous molecular topological indices related to some chemical and physical properties of chemical compounds were put forward. Among these topological indices, the VDB topological indices rely only on the vertex degree of chemical molecular graphs. The VDB topological index of an $ n $-order graph $ G $ is defined as TI(G) = \sum\limits_{1\leq i\leq j\leq n-1}m_{ij}\psi_{ij}, $ where $ \{\psi_{ij}\} $ is a set of real numbers, $ m_{ij} $ is the quantity of edges linking an $ i $-vertex and another $ j $-vertex. Numerous famous topological indices are special circumstance of this expression. f-benzenoids are a kind of polycyclic aromatic hydrocarbons, present in large amounts in coal tar. Studying the properties of f-benzenoids via topological indices is a worthy task. In this work the extremum $ TI $ of f-benzenoids with given number of edges were determined. The main idea is to construct f-benzenoids with maximal number of inlets and simultaneously minimal number of hexagons in $ \Gamma_{m} $, where $ \Gamma_{m} $ is the collection of f-benzenoids with exactly $ m $ $ (m\geq19) $ edges. As an application of this result, we give a unified approach of VDB topological indices to predict distinct chemical and physical properties such as the boiling point, $ \pi $-electrom energy, molecular weight and vapour pressure etc. of f-benzenoids with fixed number of edges.

Surface-Enhanced Raman Spectroscopic Investigation of PAHs at a Fe3O4@GO@Ag@PDA Composite Substrates.

A method for surface-enhanced Raman spectroscopy (SERS) sensing of polycyclic aromatic hydrocarbons (PAHs) is reported. Fe3O4@PDA@Ag@GO is developed as the SERS substrate prepared by classical electrostatic attraction method based on the enrichment of organic compounds by graphene oxide (GO) and polydopamine (PDA) and the good separation and enrichment function of Fe3O4. The morphology and structure of the SERS substrate were represented by transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD) and the UV–visible absorption spectrum (UV–vis spectra). The effect of different temperatures on SERS during synthesis was investigated, and it was found that the best effect was achieved when the synthesis temperature was 90 °C. The effect of each component of Fe3O4@PDA@Ag@GO nanocomposites on SERS was explored, and it was found that Ag NPs are of great significance to enhance the Raman signal based on the electromagnetic enhancement mechanism; apart from enriching the polycyclic aromatic hydrocarbons (PAHs) through π–π interaction, GO also generates strong chemical enhancement to the Raman signal, and PDA can prevent Ag from shedding and agglomeration. The existence of Fe3O4 is favored for the fast separation of substrate from the solutions, which greatly simplifies the detection procedure and facilitates the cycle use of the substrate. The experimental procedure is simplified, and the substrate is reused easily. Three kinds of PAHs (phenanthrene, pyrene and benzanthene) are employed as probe molecules to verify the performance of the composite SERS substrate. The results show that the limit of detection (LOD) of phenanthrene pyrene and benzanthene detected by Fe3O4@PDA@Ag@GO composite substrate are 10−8 g/L (5.6 × 10−11 mol/L), 10−7 g/L (4.9 × 10−10 mol/L) and 10−7 g/L (4.4 × 10−10 mol/L), respectively, which is much lower than that of ordinary Raman, and it is promising for its application in the enrichment detection of trace PAHs in the environment.

Effect of terminal electron acceptors on the anaerobic biodegradation of PAHs in marine sediments

The existing polycyclic aromatic hydrocarbons (PAHs) in marine sediment has become a critical threat to biological security. Terminal electron acceptor (TEA) amendment has been applied as a potential strategy to accelerate bioremediation in sediment. HCO3-, NO3-, and SO42- were separately added to anaerobic sediment system containing five kinds of PAH, namely, phenanthrene, anthracene, fluoranthene, pyrene and benzo(a)pyrene. PAH concentration, PAH metabolites, TEA concentration, and electron transport system (ETS) activity were investigated. The HCO3- amendment group achieved the max PAH degradation efficiency of 84.98 %. SO42- group led to the highest benzo(a)pyrene removal rate of 69.26 %. NO3- had the lowest PAH degradation rate of 76.16 %. ETS activity test showed that NO3- significantly inhibited electron transport activity in the sediment. The identified PAH metabolites were the same in each group, including 4,5-dimethylphenanthrene, 3-acetylphenanthrene, 9,10-anthracenedione, pyrene-7-hydroxy-8-carboxylic acid, anthrone, and dibenzothiophene. After 126 d's anaerobic degradation at 25 °C, the utilization of HCO3- and SO42- as selected TEAs promoted the PAH biodegradation performance better than the utilization of NO3-.

Longitudinal relationships between polycyclic aromatic hydrocarbons exposure and heart rate variability: Exploring the role of transforming growth factor-β in a general Chinese population

We aim to investigate the long-term adverse effects of polycyclic aromatic hydrocarbons (PAHs) exposure on heart rate variability (HRV) reduction, and to assess the potential role of transforming growth factor-β1 (TGF-β1) in such relationship. We enrolled 2985 adult residents with 4100 observations who participated at baseline and 6-years follow-up from Wuhan-Zhuhai cohort. Ten detectable urinary PAHs metabolites and two HRV indices were repeatedly measured at baseline and follow-up; and plasma TGF-β1 levels were also determined for all subjects. We observed that both total urinary low molecular weight PAHs (ΣLWM OH-PAH) and total urinary high molecular weight PAHs (ΣHWM OH-PAH) were negatively associated with HRV reductions (P < 0.05). Subjects with persistent high levels of ΣHWM OH-PAH had a significant reduction in HRV over 6 years, and the incensement of TGF-β1 could aggravate above adverse effects in a dose-response manner. All kinds of PAHs were positively associated with plasma TGF-β1 elevation, which in turn, were negatively related to HRV indices. Increased TGF-β1 significant mediated 1.34–3.62% of PAHs-associated HRV reduction. Our findings demonstrated that long-term high levels of PAHs exposure could cause HRV reductions, and TGF-β1 may play an essential role in such association.

In utero exposure to mixed PAHs causes heart mass reduction in adult male mice

Polycyclic aromatic hydrocarbons (PAHs) are a risk factor for the occurrence of cardiac diseases. The present study was conducted to investigate the influence of prenatal exposure to a mixed PAHs on heart and the underlying mechanism. Pregnant mice were orally administered with a mixture of 8 kinds of PAHs (0, 5, 50, 500 μg/kg body weight) once every 2 days for a total of 8 dosages. The mixed PAHs contained naphthalene, acenaphthylene, phenanthrene, fluoranthene, pyrene, benzo[a]pyrene, dibenzo[a,h]anthracene and benzo[g,h,i]perylene at a weight ratio of 10: 10: 10: 10: 10: 1: 1: 1. The adult males, not females, showed significantly decreased heart/body weight ratio, which was attributed to the loss of cardiac fiber and the increase of cell apoptosis. The protein expression of transforming growth factor β1 and its downstream transcription factors, Smad3 and Smad4, was significantly downregulated, which caused the loss of cardiac fiber. The downregulated phosphatidylinositol 3-kinase and AKT led to increased expression of caspase3, caspase9, BAX and reduced expression of Bcl-2, which was responsible for the increased cell apoptosis. Different levels of aromatic hydrocarbon receptor and sex hormone receptors between males and females were associated with the distinct effect on heart.

Bioaccumulation and function analysis of glutathione S-transferase isoforms in Manila clam Ruditapes philippinarum exposed to different kinds of PAHs

This study analyzed the function of different glutathione S-transferase (GST) isoforms and detoxification metabolism responses in Manila clam, Ruditapes philippinarum, exposed to 4 kinds of polycyclic aromatic hydrocarbons (PAHs) single, and their mixtures for 15 days under laboratory conditions. 13 kinds of GSTs in R. philippinarum were classified, and the results of tissue distribution indicated that 12 kinds of GSTs (except GST sigma 3) expressed most in digestive glands. We detected the mRNA expression levels of aryl hydrocarbon receptor signaling pathway, and detoxification system in digestive glands of clams exposed to benzo[a]pyrene (BaP), chrysene (CHR), benzo[a]anthracene (BaA), benzo[b]fluoranthene (BbF), and BaP + CHR + BaA + BbF, respectively. Among these genes, we selected GST-sigma, GST-omega and GST-pi as potential indicators to BaP; GST-sigma, GST-A and GST-rho to CHR; GST-pi, GST-sigma, GST-A, GST-rho and GST-microsomal to BaA; GST-theta and GST-mu to BbF; while GST-pi and GST-mu to the mixture of BaP, CHR, BaA and BbF. Additionally, the bioaccumulation of PAHs in tissues increased remarkably over time, and showed an obvious dose-effect. Under the same concentration, the bioaccumulation in single exposure group was higher than that in mixture group, and the bioaccumulation of PAHs in tissues with different concentrations of stress was irregular. The results revealed the metabolic differences and bioaccumulation rules in clams exposed to four kinds of PAHs, and provided more valuable information for the PAHs risk assessment.

Distribution, sources, and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments from Daya Bay, South China.

In this study, the concentrations of 16 kinds of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of Daya Bay were determined and analyzed. Results showed that 16 PAHs were detected in all the samples, and the total PAH concentration ranged from 70.18 to 128.04 ng g-1, with an average of 103.17 ng g-1. The cyclic number distribution of PAHs in the sediments was mainly 4 and 5 rings. Six classic PAH ratios named Ant/(Ant + Phe), Fla/(Fla + Pyr), [InP/(InP + BghiP)], [BaA/(BaA + Chr)], BaA/BghiP, and LMW/HMW, and principal component analyses showed that the main source of PAHs in this region was combustion (biomass, coal, and petroleum combustion), and the secondary source was petroleum. The ecological risk analysis of PAHs by using effect range low/median method and mean effects range-median quotient method showed that all of PAHs are lower than the effect range low (ERL) level and the effects range-median quotient (M-ERM-Q) value of all stations is 0.0027-0.0067, with an average value of 0.0046. Thus, it can be seen that PAHs are at a low-risk level in surface sediments of Daya Bay.

Determination of Benzopyrene in edible fish

Benzopyrene is a kind of polycyclic aromatic hydrocarbons and a strong carcinogen. Now, more attention has been paid to benzopyran pollution in food. In this paper, taking the edible fish in Yingkou area as the representative, the extraction solution was determined by UV-Vis spectrophotometer. The results showed that the content of benzopyrene in the three kinds of edible fish was less than the national standard among them, the benzopyrene content of sea catfish is high, and then the risk of carcinogenesis and pollution are analyzed, the results are within the safe range.

Extremality of VDB topological indices over f–benzenoids with given order

In the theoretical chemistry, pharmacology and biology literature, numerous VDB topological indices were introduced to predict physio-chemical properties of chemical compounds. As a kind of polycyclic aromatic hydrocarbons, f–benzenoids are abundant in real substances such as coal tar, etc. It is valuable to study the attributes of f–benzenoids by virtue of topological indices. The main dedication of this paper is to obtain extremal values for VDB topological indices of f–benzenoids with a given order. Furthermore, the extremal f–benzenoids attaining these values are also characterized.

Study on release characteristics and removal of polycyclic aromatic hydrocarbons in solid waste coking sulfur paste during heating

ABSTRACT Coking sulfur paste (CSP) is a hard-to-handle industrial solid waste. With the high sulfur content, CSP can be used to prepare asphalt modifier. This paper investigated the release characteristics of polycyclic aromatic hydrocarbons (PAHs) in CSP during heating. While heating from 42°C to 480°C, CSP demonstrated two weight loss stages in which certain organic compounds were evaporated from CSP. The volatiles were primarily benzene and four kinds of PAHs, including naphthalene, indene, fluorene, and phenanthrene. The total absolute release amount of volatiles increased with increase in temperature. Furthermore, to remove PAHs, CSP was sulfonated with 98% H2SO4. The optimal sulfonation conditions in the molten state of CSP were as follows: ratio of H2SO4 volume to CSP mass 60 μL·g−1 and reaction time 60 min. At 160°C, the total absolute release amount of benzene and four kinds of PAHs decreased from 14.688 × 103 to 0.18 μg·g−1. Therefore, the removal of PAHs from CSP using a sulfonation agent is very effective, ensuring that CSP can be used in road engineering without pollution.

Facile preparation of novel COFs functionalized magnetic core-shell structured nanocomposites and used for rapid detection of trace polycyclic aromatic hydrocarbons in food

A facile and rapid magnetic solid phase extraction (MSPE) based on magnetic covalent organic framework and coupled with high performance liquid chromatography diode array detection (HPLC-DAD) has been developed for detection of 11 kind of polycyclic aromatic hydrocarbons (PAHs) in food samples. In this paper, the novel magnetic core-shell structured (Fe3O4@COFs) nanocomposites were consisted with the magnetic Fe3O4 nanoparticles (NPs) as a core, and 1,3,5-tris (4-aminophenyl) benzene (TAPB) and 2,5-dihydroxyterephthalaldehyde (DP) as two ligands for building shell outside of the core. These new nanocomposites were applied as superior adsorbent to enrich the PAHs due to their merits of large specific surface area, highly porosity and excellent thermal stability. The conditions that may affect the enrichment efficiency in MSPE process, including desorption solvent, amount of sorbent, extraction time, desorption time and desorption adsorption volume were investigated systematically. By combining MSPE with HPLC-DAD, an effective method for the detection of trace PAHs was successfully developed, which exhibited good linearity with R2 ranging from 0.9954 to 0.9988, satisfactory recoveries in the range of 83.2–119.3%, and the relative standard deviations (RSD) was lower than 5.8%. In addition, the proposed MSPE-HPLC-DAD method was shown excellent ability to enrich trace PAHs effectively in food samples and potential application in extract other aromatic compounds.

Simultaneous determination of 16 polycyclic aromatic hydrocarbons in source water and tap water by performance liquid chromatography with ultraviolet detector tandem fluorescence detector combined with solid phase extraction

To establish a rapid method for simultaneous determination of 16 polycyclic aromatic hydrocarbons(PAHs) in source water and tap water by performance liquid chromatography(HPLC) with ultraviolet detector(UV) tandem fluorescence detector(FLR). Source water was filtered by GF/C glass fiber filters and tap water were added ascorbic acid of 60 mg per liter to remove the residual chlorine when sampling. 500 mL water sample were sampled and adjusted pH 2 with phosphoric acid, then 10 mL methanol were added. Then samples were concentrated by styrene stilbene polymer solid phase extraction column, after loading samples, 50 percent methanol aqueous solution adjust pH 2 were used for washing bottle and the washed solution were continuum loaded. Then 80 percent methanol aqueous solution was used for removing impurity interference and elution with dichloromethane. The eluent was nitrogen blow to near dry after adding 100 μL 10 percent tween-20 methanol solutions(m/V). Acetonitrile was used for reconstitution, and then separated by PAH chromatography column using acetonitrile and pure water at gradient elution, and detected by UV tandem FLR detector. The linear ranges of 16 PAHs were 0. 5 to 500 ng/mL and the correlation coefficients were greater than 0. 999. The method detection limit and limits of quantification were 0. 3 to 5. 0 ng/L and 1. 2 to 20. 0 ng/L, respectively. The recoveries were in the range of 67. 2%-114. 1% with the relative standard deviations ranging from 1. 5%-14. 0%(n=6). Then the established method was used for the determination of 17 water samples, 8 kinds, 6 kinds and 7 kinds of PAHs were detected in source water, tap water and pipe net tap water, respectively. The method is rapid, sensitive and selective, and has been successfully applied for determination of 16 PAHs in source water and tap water.

Phytoremediation effect of Medicago sativa colonized by Piriformospora indica in the phenanthrene and cadmium co-contaminated soil

BackgroundThe coexistence of polycyclic aromatic hydrocarbons (PAHs) and heavy metals has deleterious effects on environmental quality. Few reports have studied the mechanisms of plant inoculation with Piriformospora indica to remediate PAH-metal co-contaminated soil by analyzing the chemical speciation of the contaminants. This study investigated the influence of the inoculation of Medicago sativa with P. indica to remediate soil co-contaminated with phenanthrene (a kind of PAH) and cadmium (a heavy metal) by analyzing plant growth, physiological parameters and chemical speciation in rhizosphere and nonrhizosphere soils.ResultsThe presence of P. indica significantly increased plant tolerance, chlorophyll a, chlorophyll b, maximum quantum efficiency of PSII photochemistry and electron transport rate values in phenanthrene- and/or cadmium-contaminated soil. P. indica inoculation in M. sativa roots increased fluorescein diacetate activities in soils contaminated with phenanthrene, cadmium or both, especially in the nonrhizosphere. The presence of phenanthrene prevented the inoculated plant from accumulating cadmium to some extent, whereas the presence of cadmium did not prevent the degradation of phenanthrene in either the rhizosphere or the nonrhizosphere after P. indica colonization. Although the low bioavailability of cadmium in the rhizosphere restricted its transportation into the stem, P. indica colonization in plants effectively increased cadmium accumulation in roots in soil co-contaminated with cadmium and phenanthrene.ConclusionsIn conclusion, this work provides a theoretical basis for the use of P. indica combined with M. sativa for the remediation of PAH-metal co-contaminated soil.

Influence of Benz[a]anthracene on Bone Metabolism and on Liver Metabolism in Nibbler Fish, Girella punctata.

It has been reported that spinal deformity was induced in developing fish by the addition of polycyclic aromatic hydrocarbons (PAHs). To examine the mechanism of the disruption of fish bone metabolism, the effect of benz[a]anthracene (BaA), a kind of PAH, on plasma calcium, inorganic phosphorus, osteoblasts, and osteoclasts was investigated in this study. We also measured several plasma components to analyze the toxicity of BaA on other metabolisms. BaA (1 or 10 ng/g body weight) was intraperitoneally injected (four times) into nibbler fish during breeding, for 10 days, and it was indicated, for the first time, that injecting high doses of BaA to nibbler fish induced both hypocalcemia and hypophosphatemia. Furthermore, in the scales of nibbler fish treated with high doses of BaA, both osteoclastic and osteoblastic marker messengerRNA (mRNA) expressions decreased. These results are a cause of disruption of bone metabolism and, perhaps, the induction of spinal deformities. In addition, we found that total protein, metabolic enzymes in the liver, total cholesterol, free cholesterol, and high-density lipoprotein cholesterol levels significantly decreased in BaA-injected fish. These results indicate that BaA may affect liver diseases and emphasize the importance of prevention of aquatic PAH pollution.

Ultrasensitive Detection of Polycyclic Aromatic Hydrocarbons (PAHs) in Water Using Three-Dimensional SERS Substrate Based on Porous Material and pH 13 Gold Nanoparticles

Sensitivity is crucially important for surface-enhanced Raman spectroscopy (SERS) application to detect trace-level polycyclic aromatic hydrocarbons (PAHs) in the seawater. In this study, a high sensitivity three-dimensional (3-D) SERS substrate composed with syringe filter, glycidyl methacrylate-ethylene dimethacrylate (GMA-EDMA) porous material and optimal parameters (57 nm, pH 13) gold nanoparticles (AuNPs) was developed for the detection of PAHs in water. The enhancement effect and repeatability of this 3-D substrate were also explored. The Raman intensity of pyrene using 3-D SERS substrate is about 8 times higher than that of substrate only using pH 13 gold colloid solution and about 12 times higher than that of substrate using natural AuNPs and GMA-EDMA porous material, which means both the pH 13 AuNPs and the GMA-EDMA porous material are important factors for the sensitivity of this 3-D SERS substrate. Good repeatability of this optimal 3-D substrate was obtained. The relative standard deviation (RSD) is less than 8.66% on the same substrate and less than 3.69% on other different substrates. Four kinds of PAHs, i.e., phenanthrene, pyrene, benzo(a)pyrene, benzo(k)fluoranthene and their mixture, were detected at the different concentrations. Their limits of detection (LODs) are 8.3×10−10 (phenanthrene), 2.1×10−10 (pyrene), 3.8×10−10 (benzo(a)pyrene) and 1.7×10−10mol L−1 (benzo (k)fluoranthene), respectively. In addition, these four PAHs were also detected by fluorescence spectroscopy to evaluate the sensitivity of SERS technology using this optimal 3-D SERS substrate. The results showed that the sensitivity of SERS based on the 3-D SERS substrate even using the portable Raman system was closed to that of fluorescence spectroscopy. Therefore, the SERS technology using this optimal 3-D substrate is expected to be an in-situ method for the detection of environmental PAHs.

Distribution Pattern, Emission Characteristics and Environmental Impact of Polycyclic Aromatic Hydrocarbons (PAHs) in Download Ash and Dust from Iron and Steel Enterprise.

Download ash and emission dust samples were collected from sintering, coking, ironmaking and steelmaking processes of iron and steel enterprises in Laiwu. Sixteen kinds of polycyclic aromatic hydrocarbons (PAHs) in the United States Environmental Protection Agency (USEPA) priority controlled lists were quantitatively analyzed using Gas Chromatography-Mass Spectrometer (GC-MS). Laser particle size analyzer was used to obtain the distribution pattern of download ash. It was found that the diameter distribution pattern from four production processes was quite different. The proportion of fine particulate (0–2.5 μm) was the highest (72.62%) in the steelmaking refining process, and was 28.962% in the ironmaking process. Moreover, the particle size in download ash from steelmaking refining is all less than 10 μm and that from the ironmaking process was 52.92%. The medium-sized particles (10–100 μm) were dominant in sinter and coking download ashes. The total PAHs (∑16PAHs) mass concentration ranged from 0.49 ± 0.06 to 69.63 ± 5.57 μg·g−1 in download ash samples, and varied from 2.815 ± 0.253 to 19.429 ± 2.545 μg·m−3 in emission dust samples. The ∑16PAHs values were both largest in download ash and dust emission from the coking process (69.63 ± 5.57 μg·g−1 and 19.429 ± 2.545 μg·m−3, respectively). The most abundant individual PAHs were benzo[b]fluoranthene, benzo[k]fluoranthene, phenanthrene, benzo[a]anthracene in ash samples, and benzo[a]anthracene, benzo[k]fluoranthene, benzo[b]fluoranthene and indeno[1,2,3-cd]pyrene in emission dust samples. Dominant compounds were high-molecular weight (four- to six-ring) PAHs in both ash and dust samples. The concentration order of individual compounds in PM10 and PM2.5 in ambient air around the steel plant was completely consistent with each other, and the concentration of ∑16PAHs was the highest in the steel plant and lowest in Daqin village because of upwind of the steel plant. The concentrations of benzo[b]fluoranthene and fluoranthene in ambient air were comparatively high, and were in accordance with the higher concentration of the two monomers in the download ash samples, which suggested that the effect of the emission flue gas from the steel plant on ambient air was necessary to concern.

Influence of smear matrix types on detection behaviors and efficiencies of polycyclic aromatic hydrocarbons using ion mobility spectrometry

Influence of smear matrix types on detection behaviors and efficiencies of polycyclic aromatic hydrocarbons (PAHs) with different molecular weights in ion mobility spectrometry (IMS) were investigated. Various smear matrices of stainless steel mesh (SM), cellulose paper (CP), and cotton fabric (CF) were employed. Anisole was used as the solvent and IMS analysis was performed without evaporation step of the solvent to apply charge transfer reactions between PAH molecules and the molecular ions of solvent. Shapes of reactant ion peaks (RIPs) were varied according to the smear matrix types. At the beginning of the sample inlet, intensity of RIPs of air and moisture notably decreased due to the lots of solvent vapor. The SM with good gas permeability showed relatively strong RIPs of air and moisture, whereas the CP with no gas permeability showed weak ones. Detection times and efficiencies of PAH ions were varied according to the smear matrix types as well as the kinds of PAHs. PAHs were on the whole detected well in 1–3 s after the sample inlet. Detection limits of PAHs measured using the SM were slightly better than those measured using the CP, while those measured using the CP were much better than those measured using the CF. The experimental results could be explained by structures of the smear matrices and evaporation behaviors of the PAH solutions.