Platinum catalysts supported on hydrothermally stable mesoporous aluminosilicate for the catalytic oxidation of polycyclic aromatic hydrocarbons (PAHs)

Catalytic oxidation of polycyclic aromatic hydrocarbons (PAHs) was studied over platinum catalysts supported on the hydrothermally stable mesoporous aluminosilicate (SM-41). Naphthalene was chosen as a model reactant of PAHs, due to the simplest and the least toxic PAHs. Zeolite seeds crystallization method was used for synthesis of SM-41. Pt/SM-41 catalyst showed higher activity than Pt/MCM-41 for catalytic oxidation of naphthalene in the presence of 10 vol.% water vapor. Hydrothermal stability and hydrophobicity of Pt/SM-41 must be beneficial for the catalytic oxidation of naphthalene in the presence of water vapor.     

一株多环芳烃降解菌吉2及其降解能力

从中原油田毛8区块油田采出液中分离得到一株多环芳烃(PAHs)降解菌吉2,根据形态观察、生理生化、16S rRNA基因、管家基因和DNA-DNA同源性分析判断,吉2属于一株Microbacterium新种。研究发现,该菌能在萘和芘为唯一碳源的无机盐培养基中生长,也能够降解萘、菲、蒽和芘的混合PAHs。7 d对这4种PAHs的降解率分别达到了61.4%、86.6%、69.9%和18.6%。吉2对原油有很好的降解及降黏作用,7 d原油的降解速率达到了134 mg·d^-1,黏度降低了29.3%。傅里叶变换红外光谱、族组分和气相色谱-质谱分析显示吉2能够优先利用原油中含PAHs的芳香烃和胶质等组分,原油中萘系列、菲系列、噻吩系列、芴系列、(艹屈)系列、C21-三芳甾醇、芘和苯并(a)芘的相对含量都有一定程度的降低。实验结果表明吉2具有修复PAHs和原油污染的水体或土壤环境的能力,为微生物修复PAHs污染和原油污染提供了一种可行的途径。     

Photopolymerization using sensitizers of binary system of aromatic hydrocarbon and amine

Photopolymerizations of acrylonitrile and methyl methacrylate, using binary sensitizers of aromatic hydrocarbon and amine, were investigated at 30°C in N,N-dimethylformamide under the irradiation with a light of λ > 300 nm. Naphthalene, anthracene, and phenanthrene were employed as aromatic hydrocarbons in the experiment. The binary system was effective for the initiation of the monomers. The combinations of naphthalene with tertiary amines, triethylamine and N,N-dimethylaniline, were remarkably effective among various combinations. The rate of polymerization with naphthalene–triethylamine sensitizer was observed to be proportional to the first, ½, and ½ powers of monomer, naphthalene, and triethylamine concentrations, respectively. The kinetics of the photopolymerization are proposed, and the initiation schemes are discussed, comparing them with those in the system sensitized by aromatic ketone–amine reported previously.     

吉林市大气气溶胶中部分有机污染物的分析

利用色谱-质谱联用技术分析了大气气溶胶中的部分有机物-烷烃和多环芳烃。主要研究了多环芳烃的地区和季节分布特征。哈达湾为污染严重区域,而江南公园清洁区有机污染相对较轻。气象条件对东局子、化工学院子站有机污染有着明显的影响,总量明显高于江南公园。工业生产为其主要的污染源,萘为其主要的指示污染物。     

污泥热解过程中多环芳烃排放规律

研究了不同温度（350~1050℃）下污泥热解过程液、气、固三相产物中16种多环芳烃（PAHs）排放规律。结果表明,PAHs趋向富集于液相产物中,其次为气相产物,在液相产物中检测到所有16种PAHs,650℃液相产物中16种PAHs（∑₁₆PAHs）总质量比最高,为96%;750℃气相产物中∑₁₆PAHs质量比最高,为21.3%以上;固相产物中PAHs含量极少,仅在650℃时达1%。所有温度下液相产物中2、3和4环PAHs均占据主导地位,∑_2,3,4环PAHs质量比达95%以上,850℃时液相产物中∑EPA-PAHs含量最高,达15.25 mg·kg^-1。气相产物主要以萘（NaP）、苊烯（Acp）、芴（Flu）和蒽（Ant）PAHs为主,未检测到高环PAHs。在高温热解阶段,污泥大分子结构裂解到达高峰,伴随产物的二次断裂、合成、环化等反应,气相产物中∑_低PAHs生成含量达到最高7.248 mg·kg^-1。不同温度下污泥热解产物中PAHs的毒性当量（TEQ）变化规律与其生成量变化基本一致,在850℃时液相产物中PAHs的TEQ最高达1.129。     

Source and Toxicological Assessment of Polycyclic Aromatic Hydrocarbons in Sediments from Imo River,Southeastern Nigeria

Polycyclic aromatic hydrocarbons (PAHs) in sediments from the Imo River were analyzed to characterize their sources and assess their toxicity potential. The total PAH concentrations ranged from 409.43 to 41,198 ng/g dw with standard deviation of 4,796 ± 1,941. This wide variation reflects a localized contamination in the study area. The inadequacy in the use of traditional isomeric ratios for PAHs source characterization in sediment from tropical environments with shallow water depth of < 10 m was highlighted. A more robust principal component analysis coupled with n-alkanes unresolved complex mixture profiles approach to apportioned specific chemical signatures to samples was proposed. This approach differentiated stations that were heavily—from those that were mildly—impacted by oil and discriminated among stations that were influenced by pyrogenic sources. Effect range low (ERL) and effect range median (ERM) as well as risk quotients (RQwcs) revealed that only naphthalene, flourene, dibenzo(a,h)anthracene and low molecular weight PAHs were implicated with ERL and ERM exceeding the US National Oceanic and Atmospheric Administration's limit of concern and RQwcs > 1, as compounds of concern. The maximum toxicity equivalency value of 179.81 ng/g TEQs_carc measured for the illegal petroleum refinery site indicated that this site requires some control measure and remedial action.     

COMPARISON OF PAHS,NITRO-PAHS AND OXY-PAHS ASSOCIATED WITH AIRBORNE PARTICULATE MATTER AT ROADSIDE AND URBAN BACKGROUND SITES IN DOWNTOWN TOKYO,JAPAN

Atmospheric polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs and oxy-PAHs are emitted from primary sources. Some nitro-PAHs and oxy-PAHs can also arise from secondary formation in the atmosphere. To assess the relative importance of these sources, the polycyclic aromatic compound (PAC) concentrations were determined at a roadside (Roadside site) and on a rooftop (Urban Background site) in downtown Tokyo Japan. The concentrations of PAHs, 1-nitropyrene and oxy-PAHs at the Roadside site were higher than those at the Urban Background site, while 2-nitrofluoranthene levels were the same at both sites. However, the mean ratios of concentrations at the Urban Background site to the Roadside site were in the order 1,8-naphthalic anhydride>9,10-anthraquinone>PAHs or 1-nitropyrene or acenaphthenequinone or benzanthrone. This suggests that in addition to vehicle emissions, a considerable fraction of some of the oxy-PAHs studied originates from another source, which might be secondary formation by atmospheric PAH degradation, and this contribution varied among the oxy-PAHs.     

KINETICS OF PAHS LOSSES AND RELATIONSHIPS BETWEEN PAHS PROPERTIES AND PROPERTIES OF SOIL IN SEWAGE SLUDGE-AMENDED SOIL

Abstract

The properties of soil determine the activity of its microflora which is responsible for the degradation of polycyclic aromatic hydrocarbons (PAHs). Moreover, soil properties influence the strength of the interactions between the PAHs and individual soil components. The introduction of sewage sludge into the soil changes these properties which, in turn, changes environmental conditions. In the present studies, relationships between the PAH content and changes in selected soil properties (pH, CEC, TEB, BS, N _t ) have been evaluated. The present experiment was carried out in two blocks of experimental plots divided according to the type of plants grown. In the first block, the following field plants were grown in specific sequence, (maize, spring barley, winter rape, potatoes and cereal mixture) while in the other block a perennial, i.e. willow, was grown. Plant cultivation was carried out for 54 months, whereas the cultivation of the willow was conducted over 42 months. Each block consisted of 6 plots with a surface area of 15 m² into which sewage sludge had been introduced in the following doses: soil without fertilization – control, sludge 30, 75, 150, 300, 600 t/ha. Both the disappearance rate and the scope of the individual polycyclic aromatic hydrocarbons as determined by their respective half-lives showed that losses of these compounds depended on the sewage sludge properties (among other things, the pollutant content) as well as the sludge dose and the type of area used. The correlation coefficients determined depended on the sludge dose and the experimental variant. The highest frequency of their occurrence was found in the case of the total sum of nitrogen and cation exchange capacity for the highest sludge doses (in the experimental with willow).     

污水污泥裂解油中多环芳烃的分析

引言在一些发达国家,污水污泥热裂解技术作为能量回收型污泥处理技术已经进入商业应用阶段,其裂解产生的液体燃料能直接用于柴油机车,并与石油提炼厂生产出来的石油低级馏出液相似     

Photodegradation of Selected Aromatic Constituents of Creosote in Organic Solvents

Polycyclic aromatic hydrocarbons (PAHs), naphthalene, phenanthrene, anthracene, and pyrene were irradiated in acetonitrile (CH₃CN) and in dichloromethane (CH₂Cl₂) on individual PAH compounds and in the presence of other compounds. The observed photodegradation of PAHs was dependent on the structure of the compound. Anthracene and pyrene were the most photoreactive in dichloromethane: with total degradation after 0.5 h irradiation for anthracene and 1.5 h for pyrene. The decomposition of PAHs was faster in dichloromethane than in acetonitrile.     

Determination of Polycyclic Aromatic Hydrocarbons in F-15J,C-130H,and F-4EJ Aircraft Exhaust

There are occupational health concerns at Japan Air Self-Defense Force bases in regard to the exposure of military flightline personnel to carcinogens in aircraft emissions, such as polycyclic aromatic hydrocarbons (PAHs). To characterize the PAHs in military aircraft emissions from different types of engines, aerosol and gas samples were separately collected downwind from aircraft with a turboprop engine (C-130H), turbojet (F-4EJ), and turbofan (F-15J). The gas-phase PAHs were determined by gas chromatography coupled to mass spectrometry and the aerosol-phase PAHs were determined by high-performance liquid chromatography with fluorescence detection. The F-4EJ engine was a source of naphthalene vapor and aerosol PAHs, including carcinogens such as chrysene, benzo (b) fluoranthene, benzo (k) fluoranthene, benzo (a) pyrene, dibenzo (a,h) anthracene, benzo (ghi) perylene, and indeno (1,2,3-cd) pyrene. These heavier (five and six-ring) PAHs were also included in the emissions from the F-15J with its newer, high-temperature F-100 turbofan engine, but the concentrations were approximately one-tenth of those in the F-4EJ. In contrast to these fighter aircraft, the C-130H was found to be a significant aerosol source of the lighter, three-ring (phenanthrene and anthracene) and four-ring (fluoranthene and pyrene) PAHs, but not the heavier ones. These results demonstrate that various aircraft are sources of PAHs in the military flightline environment.     

Temperature programmed desorption of toluene, p-xylene, mesitylene and naphthalene on mesoporous high silica MCM-41 for characterizing its surface properties and measuring heats of adsorption

Temperature programmed desorption (TPD) of aromatic hydrocarbons (viz. toluene, p-xylene, mesitylene and naphthalene) on mesoporous high silica MCM-41 from 323 to 673 K at different linear heating rates (5, 10, 15 and 25 K min⁻¹) has been investigated. TPD of toluene at different adsorbate loading (0.5 to 16.3 μmol g⁻¹) has also been investigated. All the TPD curves have a single asymmetric peak. The heats of adsorption of aromatic hydrocarbons on the mesoporous material, estimated from the TPD peak maximum temperatures measured at different heating rates, was found to occur in the following order: toluene<p-xyleneH_a increases with the decrease in the ionization potential of the hydrocarbons. The adsorption results from weak interactions between the π-electrons of aromatic hydrocarbons and the terminal poorly acidic silanol (Si–OH) groups. In the case of toluene TPD, the TPD peak maximum temperature increases with decreasing the adsorbate loading, indicating the presence of site energy distribution on the high silica MCM-41.     

The Effect of Polycyclic Aromatic Hydrocarbons on the Structure of Organotrophic Bacteria and Dehydrogenase Activity in Soil

The objective of this article was to determine the structure of microbial communities and the activity of dehydrogenases in soil samples contaminated with four polycyclic aromatic hydrocarbons (PAHs), i.e., naphthalene, phenanthrene, anthracene, and pyrene, in the amount of 0, 1000, 2000, and 4000 mg kg^?1soil DM. Organic substances—cellulose, sucrose, and compost—were added to the samples in the amount of 0 and 9 g kg^?1soil DM. The experiment was performed in a laboratory on samples of loamy sand. Indices of colony development (CD) and eco-physiological diversity (EP) of organotrophic bacteria, soil resistance (RS), and soil resilience (RL) were calculated. Soil contamination with PAHs differentiated the structure of organotrophic bacteria, and the lowest CD and EP values were noted in soil samples containing pyrene. PAHs inhibited the activity of dehydrogenases, and pyrene exerted the most inhibitory effect on enzyme activity. Dehydrogenase activity was determined mainly by the applied PAH dose, the date of analysis and the type of organic substance added to soil. Low RL values indicate that exposure to PAHs induces long-term changes in dehydrogenase activity.     

东胜煤有机溶剂分级萃取物的GC/MS分析研究

用气相色谱/质谱联用技术测定了东胜煤有机溶剂萃取物的化学组成，对其化学成分及化合物分布特征进行了研究。结果表明，萃取物主要由烷烃，芳烃和衍生物三种成分组成，其中烷烃主要是正构烷烃；芳烃是萃取物最主要的成分，以萘系，蒽系，菲系，芴系和芘系的0-3烷基取代物为主，和几种高丰度的5-6环稠环芳烃；衍生物主要是多环芳香族含硫化合物，还有一种煤中首次发现的4-氨基-9-芴酮，含氧化合物仅检测到几种。     

Novel Application of Cyclolipopeptide Amphisin: Feasibility Study as Additive to Remediate Polycyclic Aromatic Hydrocarbon (PAH) Contaminated Sediments

To decontaminate dredged harbor sediments by bioremediation or electromigration processes, adding biosurfactants could enhance the bioavailability or mobility of contaminants in an aqueous phase. Pure amphisin from Pseudomonas fluorescens DSS73 displays increased effectiveness in releasing polycyclic aromatic hydrocarbons (PAHs) strongly adsorbed to sediments when compared to a synthetic anionic surfactant. Amphisin production by the bacteria in the natural environment was also considered. DSS73's growth is weakened by three model PAHs above saturation, but amphisin is still produced. Estuarine water feeding the dredged material disposal site of a Norman harbor (France) allows both P. fluorescens DSS73 growth and amphisin production.     

Evaluation of Polycyclic Aromatic Hydrocarbons Contamination in the Sediments of the Johor Strait,Peninsular Malaysia

In May 2013, sediment samples were collected from five stations in the Straits of Johor, near the southern tip of Peninsular Malaysia, in order to evaluate the distribution and sources of polycyclic aromatic hydrocarbons (PAHs). The concentrations of 16 United States Environmental Protection Agency PAHs varied from 650.5 to 1441.2 ng g ^?1 dry weight (dw) with a mean value of 985.5 ng g ^?1 dw. PAHs can be classified as moderate level pollution in the collected samples. When comparing PAHs in this study with that of the sediment quality guidelines (SQGs), it was found that the total PAHs, low molecular weight (LMW), and high molecular weight (HMW) PAHs might incur minimal adverse biological effects. The diagnostic ratios of individual PAHs indicated both petrogenic and pyrogenic origins with predominantly pyrogenic sources, the findings of which are further supported by the results from principal component analysis (PCA). The PCA results reveal contributions of 44.44%, 32.3%, and 18.96% for traffic-related, coal combustion, and petroleum-related products, respectively. These findings indicate that the effective monitoring and significant improvement resulting from the implementation of environmental regulations in Malaysia might have caused a shift in the source of petroleum hydrocarbons in the Straits of Johor's aquatic ecosystems from petrogenic to pyrogenic origins.     

Using Urban Streams as Drinking Water: The Potential Risk in Respect to Polycyclic Aromatic Hydrocarbons (PAHs) Content in Sediments

Several polycyclic aromatic hydrocarbons are considered carcinogenic and mutagenic. 16 of these compounds are listed as priority control pollutants by the USEPA. The present study aimed at the evaluation of the presence of PAHs in sediments of an urban stream by GC-MS. The study area was located in Indaiatuba-São Paulo-Brazil, and supplies to approximately 40,000 people of a region with limited availability of water. Therefore, this water body flowing in the urban region represents a case study of the potential risk in using this water for drinking. The results show that, in general, the sampling site near the intake of the water treatment plant for human consumption had the highest concentration of total PAHs (247.7μg kg^?1). This is the site that presents more contact with urban pollution and surface runoff from the streets. The PAHs composition pattern by ring number presented a higher proportion of hydrocarbons of 4- and 5-rings, and showed a tendency, in the majority of the samples, of predominance of the high-molecular-weight PAHs, except for samples collected on June 2011 that had a high concentration of naphthalene (a 2-ring PAH). The application of a principal component analysis helped to identify the sources of hydrocarbons as pyrogenic (PC1) and petrogenic origin (PC2). Through this statistical tool it is postulated that, in some periods, the stream was exposed to point and non-point sources of contamination, showing that this type of water supply option has a high degree of vulnerability mainly during the first rain after of a long dry period, and its consumption can cause long-term problems.     

Occurrence and Source Apportionment of Polycyclic Aromatic Hydrocarbons in Urban Residential Soils from National Capital Region,Uttar Pradesh,India

This study aims to investigate the level of priority polycyclic aromatic hydrocarbons (PAHs) and identification of their potential sources in residential soils. During the study, a total 36 soil samples collected from twelve residential locations at Sahibabad-Ghaziabad area of western Uttar Pradesh, India, a constituted part of the National Capital Region of India. Samples extracted using ultrasonication, cleaned with silica and analyzed by diode array detector–high-performance liquid chromatography using acetonitrile/water as mobile phase. The 25th and 75th percentile concentration of ∑PAHs was 264 μg kg^?1 and 584 μg kg^?1, respectively, with mean and median of 445 μg kg^?1 and 421 μg kg^?1. The detection frequency of PAHs in all samples was lower for low molecular weight PAHs (19%) than high molecular weight PAHs (81%). The concentration of seven probable carcinogenic PAHs accounted for 67% of the ∑PAHs. PAHs toxicity potential as benzo(a)pyrene toxicity equivalent ranged between 2.52–253 μg BaP_TEQ kg^?1. Composition profile of PAHs with different aromatic rings and selected diagnostic molecular ratios suggested the local pyrogenic sources of PAHs from vehicular emissions, diesel engines, biomass combustion, gasoline, and coal combustions.     

YEAR TIME MODULATION OF n-ALKANES,PAH, NITRO-PAH AND ORGANIC ACIDS AT MONTELIBRETTI ROME,ITALY

The organic fraction of airborne particulates was investigated at Montelibretti RM, Italy, over 12 months and n-alkanes, polycyclic aromatic hydrocarbons, nitrated polycyclic aromatics and aliphatic acids were evaluated. The year time modulations were acquired from all groups of compounds, both in quantitative (cumulative concentrations) and qualitative (percent compositions) terms. Some distribution indexes and diagnostic ratio rates drawn from congener abundances provided information about the twin nature (anthropogenic and biogenic) of sources of organic particulate. Briefly, unlike past decades the appearance of the Montelibretti location was that of a site affected overall by local pollution, as a consequence of both direct anthropogenic emissions and secondary oxidized compounds. The occurrence of polycyclic aromatic hydrocarbons (PAHs) seemed to depend overall upon vehicle emission (diesel powered in particular), although a second, unknown source with year time modulation was present, apparently not associated with biomass/wood burning. By contrast, nitro-PAHs were mainly associated to oxidation of parent PAHs. In summer, PAHs were found at concentrations similar to those measured in 1993–1995, whilst in winter they were three times more abundant than previously reported.     

Levels of Volatile Polycyclic Aromatic Hydrocarbons in the Atmosphere of Athens,Greece

Eight light polycyclic aromatic hydrocarbons (PAHs) have been measured in the gas and particle phase of the atmosphere of Athens, in one site during an eight-month period (December, 1997-July, 1998). A glass fiber filter-polyurethane foam sheet high volume air sampler was used to collect the particle and vapor phase of the eight PAHs in nineteen samples, taken from the Athens center. Methodology of sampling as well as levels and abundance of PAHs in both phases are discussed. Seasonal variation of very volatile PAHs was found not to be strictly related to high temperatures and explanations are proposed. An unexpected PAHs pattern from two summer photochemical episodes is also discussed.