Photoionization Mass Spectrometric and Kinetic Modeling of Low-pressure Pyrolysis of Benzene

Pyrolysis of benzene at 30 Torr was studied from 1360 K to 1820 K in this work. Synchrotron vacuum ultraviolet photoionization mass spectrometry was employed to detect the pyroly- sis products such as radicals, isomers and polycyclic aromatic hydrocarbons, and measure their mole fraction profiles versus temperature. A low-pressure pyrolysis model of benzene was developed and validated by the experimental results. Rate of production analysis was performed to reveal the major reaction networks in both fuel decomposition and aromatic growth processes. It is concluded that benzene is mainly decomposed via H-abstraction reaction to produce phenyl and partly decomposed via unimolecular decomposition reac- tions to produce propargyl or phenyl. The decomposition process stops at the formation of acetylene and polyyne species like diacetylene and 1,3,5-hexatriyne due to their high thermal stabilities. Besides, the aromatic growth process in the low-pressure pyrolysis of benzene is concluded to initiate from benzene and phenyl, and is controlled by the even carbon growth mechanism due to the inhibited formation of C5 and C7 species which play important roles in the odd carbon growth mechanism.

COD Removal Efficiencies of Some Aromatic Compounds in Supercritical Water Oxidation

Some aromatic compounds, phenol, aniline and nitrobenzene, were oxidized in supercritical water. It was experimentally found that the chemical oxygen demand (COD) removal efficiency of these organic compounds can achieve a high level more than 90% in a short residence time at temperatures high enough. As temperature, pressure and residence time increase, the COD removal efficiencies of the organic compounds would all increase. It is also found that temperature and residence time offer greater influences on the oxidation process than pressure. The difficulty in oxidizing these three compounds is in the order of nitrobenzene ＞ aniline ＞ Phenol. In addition, it is extremely difficult to oxidize aniline and nitrobenzene to CO2 and H2O at the temperature lower than 873.15 K and 923.15 K, respectively. Only at the temperature higher than 873.15 K and 923.15 K, respectively, the COD removal efficiencies of 90% of aniline and nitrobenzene can be achieved.

Influence of Triarylamine and Indoline as Donor on Photovoltaic Performance of Dye-Sensitized Solar Cells Employing Cobalt Redox Shuttle

Two organic dyes XSS1 and XS52 derivated from triarylamine and indoline are synthesized for dye-sensitized solar ceils （DSCs） employing cobalt and iodine redox shuttles. The effects of dye structure upon the photophysical, electro-chemical characteristics and cell perfor- mance are investigated. XS51 with four hexyloxyl groups on triarylamine performs better steric hindrance and an improvement of photovoltage. X852 provides higher short-circuit photocurrent density due to the strong electron-donating capability of indoline unit. The results from the redox electrolyte on cell performances indicate that the synthesized dyes are more suitable for tris（1,10-phenanthroline）cobalt（II/III） redox couple than I-/I3- redox couple in assembling DSCs. Application of X852 in the cobalt electrolyte yields a DSC with an overall power conversion efficiency of 6.58% under AM 1.5 （100 mW/cm2） irradiation.

Derived oil production by catalytic pyrolysis of scrap tires

Scrap tires were pyrolyzed in a continuously stirred batch reactor in the presence and absence of catalysts. The maximum yield of derived oil was up to 55.65 wt%at the optimum temperature, 500 °C. The catalytic pyrolysis was performed using 1.0 wt%（on a scrap tire weight basis） of catalysts based on ZSM‐5, USY,β, SAPO‐11, and ZSM‐22. The oil products were characterized using simula‐tion distillation, elemental analysis, and gas chromatography‐mass spectrometry. The results show that using a catalyst can increase the conversion of scrap tires to gas and decrease char by‐products;the yield of derived oil remains unchanged or a little lower. The oils derived from catalytic pyrolysis had H/C ratios of 1.55–1.65 and contained approximately 70–75 wt%light oil, 0.3–0.58 wt%S and 0.78–1.0 wt%N. Catalysts with high acid strengths and appropriate pore sizes, such as ZSM‐5, USY,β, and SAPO‐11, increased the amount of single‐ring aromatics in the light‐middle‐fraction oil to 45 wt%. The derived oil can therefore be used as a petrochemical feedstock for producing high‐value‐added chemical products or fuel oil.

Carbon film encapsulated Fe_2O_3: An efficient catalyst for hydrogenation of nitroarenes

Iron catalysis has attracted a wealth of interdependent research for its abundance,low price,and nontoxicity.Herein,a convenient and stable iron oxide(Fe2O3)‐based catalyst,in which active Fe2O3nanoparticles(NPs)were embedded into carbon films,was prepared via the pyrolysis of iron‐polyaniline complexes on carbon particles.The obtained catalyst shows a large surface area,uniform pore channel distribution,with the Fe2O3NPs homogeneously dispersed across the hybrid material.Scanning electron microscopy,Raman spectroscopy and X‐ray diffraction analyses of the catalyst prepared at900°C(Fe2O3@G‐C‐900)and an acid‐pretreated commercial activated carbon confirmed that additional carbon materials formed on the pristine carbon particles.Observation of high‐resolution transmission electron microscopy images also revealed that the Fe2O3NPs in the hybrid were encapsulated by a thin carbon film.The Fe2O3@G‐C‐900composite was highly active and stable for the direct selective hydrogenation of nitroarenes to anilines under mild conditions,where previously noble metals were required.The synthetic strategy and the structure of the iron oxide‐based composite may lead to the advancement of cost‐effective and sustainable industrial processes.

Identification of Odor Volatile Compounds and Deodorization ofPaphia undulata Enzymatic Hydrolysate

Unfavorable fishy odour is an inevitable problem in aquatic products. In the present study, headspace solid-phase mi- croextraction gas chromatography mass spectrometry （HS-SPME-GC-MS） analysis of volatiles from untreated samples and three deodorized samples （under the optimal conditions） ofPaphia undulata enzymatic hydrolysate revealed that the compounds contrib- uting to the distinctive odor were 1-octen-3-ol, n-hexanal, n-heptanal, 2,4-heptadienal, and 2,4-decadienal, whereas n-pentanal, n-octanal, n-octanol, benzaldehyde, 2-ethylfuran and 2-pentylfuran were the main contributors to the aromatic flavor. The deodoriz- ing effects of activated carbon （AC） adsorption, yeast extract （YE） masking and tea polyphenol （TP） treatment on a P. undulata en- zymatic hydrolysate were investigated using orthogonal experiments with sensory evaluation as the index. The following optimized deodorization conditions were obtained： AC adsorption （35 mg mL-1, 80℃, 40 rain）, YE masking （7 mgmL l, 45 ℃, 30 min） and TP treatment （0.4mgmL-l, 40℃, 50min）. AC adsorption effectively removed off-flavor volatile aldehydes and ketones. YE masking modified the odor profile by increasing the relative contents of aromatic compounds and decreasing the relative contents of aldehydes and ketones. The TP treatment was not effective in reducing the odor score, but it significantly reduced the relative content of alde- hydes while increasing that of alkanes. It is also notable that TP effectively suppressed trimethylamine （TMA） formation in a P. un- dulate hydrolysate solution for a period of 72 h.

Determination and Correlation for Solubility of Aromatic Acids in Solvents

Solubility of benzoic acid, terephthalic acid and 2,6-naphthalene dicarboxylic acid in water, acetic acid, N.N-dimethylformamide, N.N-dimethylacetamide, dimethyl sulphoxide and Ar-methyl-2-ketopyrrolidine were measured by dynamic method. The solubilities were calculated by UNIFAC group contribution method, in which new groups, BCCOOH and NCCOOH, were introduced to express the activity coefficients of aromatic acids and new interaction parameters of the new groups were expressed as the function of temperature, which were determined from the experimental data. The new interaction parameters provided good calculated result. The experimental data were also correlated with Wilson and y-h models, and results were compared with present UNIFAC model.

Biodegradation of ferulic acid by a newly isolated strain of Cupriavidus sp. B-8

As a major component of lignin and abundantly existing in softwood and hardwood, ferulic acid has been used as a lignin-related compound for lignin biodegradation study. Biodegradation of ferulic acid by Cupriavidus sp. B-8, a newly isolated strain, was studied. This strain is able to utilize a wide range of lignin-related aromatic compounds as the sole carbon and energy source, including guaiacol, veratric acid, vanillic acid, cinnamic acid, p-coumaric acid, ferulic acid, and sinapic acid. In addition, the effects of different concentrations of ferulic acid on growth of Cupriavidus sp. B-8 were studied. The growth of Cupriavidus sp. B-8 is better under the condition of lower concentration. High-performance liquid chromatography （HPLC） analysis reveals that above 95% of ferulic acid is degraded within 12 h by Cupriavidus sp. B-8. Based on identification of biodegradation intermediates and further metabolites, the biodegradation pathway of ferulic acid by Cupriavidus sp. B-8 was proposed. Ferulic acid is initially converted to 4-vinylguaiacol, and further oxidized to vanillic acid and protocatechuic acid.

Investigation of Swelling and Dissolution Process of Natural Rubber in Aromatic Oil

Aromatic oil has been used to promote the properties of crumb rubber modified asphalt which is an ideal method to deal with the resource utilization of waste rubber tires and by-product of refinery. Furfural extract oil(FEO) was separated into the light fraction and the heavy fraction. Swelling and dissolution process of natural rubber sheet in these three oil samples was investigated to shed light on the interaction mechanism. Crumb rubber also interacted on FEO and asphalt respectively. Energy dispersive spectrometer(EDS), thermo-gravimetric analysis(TGA) and scanning electron microscope(SEM) were used to characterize the chemical and structural properties of processed rubber. The chemical composition of processed oils and asphalt was investigated by using the hydrocarbon group analysis(SARA) and gel permeation chromatography. The results revealed that the swelling rate and mass loss of rubber in oils were much higher than those in asphalt and rose with an increasing processing temperature. The heavy fraction of FEO had more diffusion and dissolving capability than the light fraction, whilst compatibility was observed between the heavy fraction and the light fraction. Selective absorption was not observed in the study and detachment of dissolved rubber was disseminated from the outside to the inside. The cross-linking degree of the residue rubber was unchanged with the processing time, and sulfur predominantly remained in the undissolved rubber. Dissolution of crumbed rubber in oils was attributed to devulcanization, while that in the asphalt was mainly attributed to depolymerization.

Polycyclic aromatic hydrocarbon formation under simulated coal seam pyrolysis conditions

Coal seam pyrolysis occurs during coal seam fires and during underground coal gasification. This is an important source of polycyclic aromatic hydrocarbon （PAH） emission in China. Pyrolysis in a coal seam was simulated in a tubular furnace. The 16 US Environmental Protection Agency priority controlled PAHs were analyzed by HPLC. The effects of temperature, heating rate, pyrolysis atmosphere, and coal size were investigated. The results indicate that the 3-ring PAHs AcP and AcPy are the main species in the pyrolysis gas. The 2-ring NaP and the 4-ring Pyr are also of concern. Increasing temperature caused the total PAH yield to go through a minimum. The lowest value was obtained at the temperature of 600℃. Higher heating rates promote PAH formation, especially formation of the lower molecular weight PAHs. The typical heating rate in a coal seam, 5 ℃/min, results in intermediate yields of PAHs. The total PAHs yield in an atmosphere of N2 is about 1.81 times that seen without added N2, which indicates that an air flow through the coal seam accelerates the formation of PAHs. An increase in coal particle size reduces the total PAHs emission but promotes the formation of 5- and f-ring PAHs.

LTAG Technology Passed Appraisal

Recently the LTAG technology combining selective hydro-saturation of LCO with selective catalytic cracking technology for producing high-octane gasoline or light aromatic hydrocarbons has passed technical appraisal.

Linkage of Aromatic Ring Structures in Saturates, Aromatics, Resins and Asphaltenes Fractions of Vacuum Residues Determined by Collision-Induced Dissociation Technology

The linkage of aromatic ring structures in vacuum residues was important for the refining process. The Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS) combined with collision-induced dissociation(CID) is a powerful method to characterize the molecular structure of petroleum fractions. In this work, model compounds with different aromatic ring structures were measured by CID FT-ICR MS. The cracking of the parent ions and the generated fragment ions were able to distinguish different linkage of the model compounds. Then, vacuum residues were separated into saturates, aromatics, resins and asphaltenes fractions(SARA), and each fraction was characterized by CID technology. According to the experimental results, the aromatic rings in saturates and aromatics fractions were mainly of the island-type structures, while the aromatic rings in resins and asphaltenes fractions had a significant amount of archipelago-type structures.

Quantum Chemistry of PAHs Thermal Cracking with Different Hydrogenation Degree

In order to investigate the influence of hydrogenation degree and structural variety on reaction trend of polyaro- matic hydrocarbons (PAHs) in resins and asphaltenes portion of heavy oil, a series of PAHs with different hydrogenation degree were selected as model compounds to simulate their different hydrogenation stage, and the PAHs thermal cracking reaction was simulated based on free radical mechanism by the density functional theory (DFT) to search for reactions'transition state. By comparing the dynamic data obtained from reaction simulation, it is showed that processing difficulty could rise with increasing condensed aromatic ring number, and hydrogenation could promote ring cleavage reaction, but excessive hydrogenation would decrease the oil conversion rate to reduce light-end products. In conclusion, proper hydrogenation was quite critical in promoting light-end products conversion efficiency and saving the processing cost as well. Operational instructions were given based on both PAHs hydrogenation performance and conclusions were drawn up from reaction simulation results.

Polyaromatic Hydrocarbon Degradation of Moss Endophytic Fungi Isolated from Macromitrium sp. in Sri Lanka

Polyaromatic hydrocarbons （PAHs）, which are the major by-products of fossil fuel burning, are released to the environment with the immense growth of urbanization and industrialization. These pollutants are subsequently deposited on many substrates including plant surfaces. Due to their toxicity, mutagenicity, carcinogenicity and recalcitrant nature, they can result in many hazardous effects on human health. Application of endophytes in bioremediation has shown much promise in removing these PAHs from contaminated substrates. In the present study, an attempt was made to isolate and identify endophytic fungi from the moss plant Macromitrium sp. （frequently available） in Sapugaskanda （highly polluted） and HettimuUa （less polluted） areas in Sri Lanka. Subsequently, their potential in degrading PAHs （naphthalene and phenanthrene） was investigated. Endophytes from the moss were isolated following the surface sterilization method, and their physiological roles in degrading naphthalene and phenanthrene were carried out using plate assays, spectrophotometric and high-performance liquid chromatography （HPLC） analysis. Most of the endophytie fungi isolated from Macromitrium sp. were able to grow in Bacto Bushnell-Haas （BBH） medium incorporated with naphthalene and phenanthrene, separately, displaying colony diameters more than 30 mm. As per the results obtained from spectrophotometric and HPLC analysis, Penicillium oxalicum, Nigrospora oryzae, Aspergillus oryzae, A. aculeatus, Penicillium sp.1, Penicillium sp.5, Eupenicillium sp.2 and Mortierella sp.1 degraded both naphthalene and phenanthrene more than 85%. The fmdings of the present investigation provide some insight into how these endophytic fungi could be used for bioremediation of PAHs in environmental sites where contamination prevails, and also open avenues for future research in the relevant field.

寻找张芳.李芳.王芳和她们的伙伴

我不认识北京电视台解芳，只是在荧屏上看见过她两眼。但看了她与她的伙伴们从1996年12月至2000年12月历时四年才摄制完成的100部电视短剧《咱老百姓》，敬仰和钦佩之心便油然而生。

Supported noble metal nanoparticles as photo/sono-catalysts for synthesis of chemicals and degradation of pollutants

This review summarizes the utilization of supported noble metal nanoparticles (such as Au/TiO2, Au/ZrO2, Ag/AgCl) as efficient photo/sono-catalysts for the selective synthesis of chemicals and degradation of environmental pollutants. Supported noble metal nanoparticles could efficiently catalyze the conversion of solar energy into chemical energy. Under UV/visible light irradiation, important chemical transformations such as the oxidation of alcohols to carbonyl compounds, the oxidation of thiol to disulfide, the oxidation of benzene to phenol, and the reduction of nitroaromatic compounds to form aromatic azo compounds, are effectively achieved by supported noble metal nanoparticles. Under ultrasound irradiation, supported noble metal nanoparticles could efficiently catalyze the production of hydrogen from water. Moreover, various pollutants, including aldehydes, alcohols, acids, phenolic compounds, and dyes, can be effectively decomposed over supported noble metal nanoparticles under UV/visible light irradiation. Under ultrasound irradiation, pollutant molecules can also be completely degraded with supported noble metal nanoparticles as catalysts.

Feasibility of Tea Saponin-Enhanced Soil Washing in a Soybean Oil-Water Solvent System to Extract PAHs/Cd/Ni Efficiently from a Coking Plant Site

Mixed contaminated brownfield sites have brought serious risks to human health and environmental safety. With the purpose of removing polycyclic aromatic hydrocarbons （PAHs） and heavy metals from a coking plant site, an innovative technology for ex-situ washing was developed in the present work. The combination of 15.0 mLL-1 soybean oil and 7.5 g L-1 tea saponin proved an effective method to extract co-pollutants from soil. After two consecutive washing cycles, the efficiency rates of removal for 3-, 4-, 5（＋6）-ring, and total PAHs, Cd, and Ni were approximately 98.2%, 96.4%, 92.3%, 96.3%, 94.1%, and 89.4%, respectively. Meanwhile, as evaluated by Tenax extraction method and metal stability indices, the residual PAHs and heavy metals after consecutive washing mainly existed in the form with extremely low bioaccessibility in the soil. Thus, in the soil after two washing cycles, there appeared limited environmental transfer risk of co-pollutants. Moreover, a subsequent precipitation method with alkaline solution and PAH- degrading strain Sphingobium sp. PHE9 inoculation effectively removed 84.6%-100% of Cd, 82.5%-91.7% of Ni, and 92.6%-98.4% of PAHs from the first and second washing solvents. The recovered solvents also exhibited a high recycling effectiveness. Therefore, the combined cleanup strategy proposed in this study proved environmentally friendly, which also played a major role in risk assessment and marlagement in mixed polluted sites.

Potential of the White-Rot Fungus Pleurotus pulmonarius F043 for Degradation and Transformation of Fluoranthene

Fluoranthene, a four-ring polycyclic aromatic hydrocarbon that is possible genotoxic in nature, has been used as an indicator for assessing polycyclic aromatic hydrocarbon （PAH）-containing pollutants. Microbial degradation is one of the promising methods in removing up PAH-contaminated environments. White-rot fungi have showed the ability to degrade a wide range of PAHs. This study aimed to investigate enzyme production, fungal biomass, and glucose utilization during the biodegradation process of fiuoranthene by a white-rot fungus Pleurotus pulmonarius F043 and to identify the metabolites produced in the degradation process. The extracellular ligninolytic enzyme system of the fungi, producing laccases and peroxidases, was directly linked to the biodegradation of fiuoranthene. The production of ligninolytic enzymes during fluoranthene degradation was related to an increase in the biomass of Pleurotus pulmonarius F043. Fluoranthene removal decreased with an increase in fluoranthene concentrations. The highest biomass production of Pleurotus pulmonarius F043 （〉 4 400 mg L-1） was found in the 10 mg L-1 fluoranthene culture after 30 d of incubation. Two fluoranthene metabolites, naphthalene-l,8-dicarboxylic acid and phthalic acid, were found in the process of fluoranthene degradation. Laccase was revealed as the major enzyme that played an important role in degradation process. Suitable conditions must be found to promote a successful fungal biotransformation augmentation in liquid culture.

PAHs Sorption and Desorption on Soil Influenced by Pine Needle Litter-Derived Dissolved Organic Matter

Study of the relationship between plant litter-derived dissolved organic matter(DOM) and organic pollutant transport in soil is important for understanding the role of forest litter carbon cycling in influencing pollutant behaviour and fate in forest soil.With the aim of providing insight into the capacity of plant litter-derived DOM to influence sorption and desorption of selected polycyclic aromatic hydrocarbons(PAHs) on soil, batch experiments were carried out with application of a sorption-desorption model incorporating DOM effects. Freshly fallen pine(Pinus elliottii) needles were used as the source of organic matter. Input of the pine needle litter-derived DOM was found to significantly decrease desorption hysteresis as well as soil adsorption capacity of phenanthrene(PHE) and fluoranthene(FLA). Addition of 1 728 mg L-1dissolved organic carbon(DOC) lowered the organic carbon-normalized sorption distribution coefficient of PHE from 7 776 to 2 541 L kg-1C and of FLA from 11 503 to 4 368 L kg-1C. Decreases of the apparent sorption-desorption distribution coefficients of PHE and FLA with increased DOC concentration indicated that DOM favored desorption of PAHs from soil. Increases in the fraction of apparently dissolved PAHs were attributable to the dissolved PAH-DOM complexes, accounting for the dissolved proportions of 39% to 69% for PHE and 26% to 72% for FLA in the sorption and desorption processes as the concentration of the added DOM solution rose from 0 to 1 728 mg L-1. Our results suggest that pine needle litterderived DOM can have a substantial effect of inhibiting PAHs sorption and promoting PAHs desorption, thus leading to enhanced leaching in soil, which should be taken into account in risk assessment of PAHs accumulated in forest soil.

Enhanced Desorption of PAHs from Manufactured Gas Plant Soils Using Different Types of Surfactants

Surfactant enhanced remediation is thought to be an effective method for the remediation of soils polluted with hydrophoblc organic compounds. Desorption of polycyclic aromatic hydrocarbons （PAHs） from an abandoned manufactured gas plant （MGP） soil was evaluated using four eluting agents including Triton X-100 （TX100）, sodium dodecylbenzene sulfonate （SDBS）, rhamnolipid water solution （RWS） and rhamnolipid fermentation broth （RFB）. The weight solubilization ratios for acenaphthene and fluorene were in the order of TX100 〉 SDBS 〉 RWS 〉 RFB. The Sm value, which indicates the maximum amounts of surfactants adsorbed in the soil, was in the order of RWS 〉 RFB 〉 SDBS 〉 TX100. By using 8 g L-1 of TX100, SDBS and RWS and 100% of RFB, the T-PAHs removal for the MGP soil contaminated with 207.86 mg T-PAHs kg-1 dry soil was 48.0%, 45.7%, 1.9%, and 8.6%, respectively, while that decreased to 41.6%, 37%, 0.38%, and 1.3% for the soil contaminated with 3494.78 mg T-PAHs kg-1 dry soil. Only 8 g L-1 TX100 could remove all types of the 16 PAHs partly in the MGP soil, and the removal efficiencies of different PAHs ranged from 13% to 77.8%. The results of this study herein provide valuable information for the selection of TX100 surfactant for remediating PAH-contaminated soils in MGP.