Shan Fu

Spatial Characteristics and Major Sources of Polycyclic Aromatic Hydrocarbons from Soil and Respirable Particulate Matter in a Mega-City, China

As one of China’s great metropolises, Taiyuan is generally recognized to be one of the most polluted cities from polycyclic aromatic hydrocarbons (PAHs) in the world. Therefore, this study was conducted to determine a total of 16 PAH concentrations in various environmental media in Taiyuan. The total PAHs concentration ranged from 1.0 to 26xa0μgxa0g−1 in soil, 1.2xa0×xa0102 to 1.4xa0×xa0103xa0ngxa0m−3 in PM 2.5 and 76 to 1.1xa0×xa0103xa0ngxa0m−3 in PM 10, respectively. Furthermore, the primary source of PAHs was coal combustion, but the samples were also affected to varying degrees by traffic emissions.

Polybrominated diphenyl ethers in atmosphere from three different typical industrial areas in Beijing, China

Three common industries that cause polybrominated diphenyl ethers (PBDEs) pollution in Beijing, China, are solid waste incineration, chemical manufacturing, and coal-fired thermal power generation. This study was conducted to determine both the concentrations and profiles of 42 PBDEs in gaseous and particulate matter (including PM2.5, PM2.5-10, and total suspended particulate (TSP)) from the major industries listed above at three sites in Beijing. The total concentration of PBDEs (defined as the sum of 42 congeners in gas and TSP) were 60.5-216 pg m(-3) at the solid waste incineration plant, 71.8-7500 pg m(-3) at the chemical plant, and 34.4-454 pg m(-3) at the coal-fired thermal power plant. The results indicate that the components of PBDE in gas were similar between three industrial sites, and the dominant congener was tri-BDEs. However, in particulate matter, the dominant BDEs were different between the three sites, possibly because they originated from different sources. In particulate matter, the dominant PBDEs were penta-BDEs at the solid waste incineration plant, deca-BDE at the coal-fired thermal power plant, and tetra-BDEs and deca-BDE at the chemical plant. Source analysis revealed that PBDE contamination might be associated with the use of different commercial PBDE flame-retardant mixtures. Results from a previous risk assessment indicated that the risk to human health was low. However, results from this study suggest that there is a potential threat associated with human exposure to PBDEs for the residents near these industrial sites.

Distribution of Polychlorinated Biphenyls in Soil Around Three Typical Industrial Sites in Beijing, China

We investigated three locations in Beijing, China, containing different industrial plants that may cause pollution of polychlorinated biphenyls (PCBs). The highest soil concentration of 1,000xa0pgxa0g−1 (dryxa0wt) was found in the chemical plant. The concentrations of ΣPCBs tended to decrease with distance from each of the investigated sites. The principal component analysis demonstrated that there were not substantial differences in PCB homologue patterns among these industrial sites. Tri-CBs and tetra-CBs were the dominant congeners. Based on the data obtained in this investigation, further study of the emission of PCBs from these industrial sites in Beijing is warranted.

Polybrominated diphenyl ethers in soil from three typical industrial areas in Beijing, China

Areas containing industrial facilities belonging to three different typical industries that may cause pollution by polybrominated diphenyl ethers (PBDEs) in Beijing, China were investigated. Specifically, the areas contained a solid waste incineration plant, a chemical factory, and a heat and power plant. Investigation of the pollution status of PBDEs in the surface soil from areas around these industries revealed the highest concentration of 42 PBDE congeners (118 ng/g, dry mass) at the solid waste incineration plant. In the other two plants, the highest concentrations were both 26 ng/g (dry mass). Among the PBDE homologues, the PBDE contamination at all sites showed similar congener compositions, with BDE 209 being the dominant congener. Our findings established the first contamination status of three typical industrial areas in Beijing. Furthermore, the total concentrations of 42 PBDE congeners tended to decrease as the distance from the investigated plants increased. Overall, these plants were identified as potential pollution sources of PBDEs in Beijing. Moreover, Pearson correlation analysis revealed that the major PBDE source in Beijing may be associated with the technical deca-BDE and penta-BDE mixture. Based on the data obtained in this preliminary investigation, further study of the potential of these sources to emit PBDEs in Beijing is warranted.

Polychlorinated biphenyls in respirable particulate matter from different industrial areas in northern China

As two typical industrial bases of Chinas great metropolises, Lingfen and Datong are affected by the steel industry, chemical plants, coal-fired power plants, and several coking plants, and face pollution from polychlorinated biphenyls (PCBs). Therefore, this study was conducted to determine the PCB concentrations in PM2.5 and PM2.5-10 samples obtained in Lingfen and Datong. We collected 22 respirable particulate matter samples (11 of PM2.5 and 11 of PM2.5-10) from Lingfen and Datong, and measured a total of 144 PCB congeners. The total PCB concentrations were 5.92-38.7 pg m(-3) (median: 21.58 pg m(-3)) in PM2.5 and 1.83-40.8 pg m(-3) (median: 24.3 pg m(-3)) in PM2.5-10 in Linfen, and 4.33-18.5 pg m(-3) (median: 11.9 pg m(-3)) in PM2.5 and 13.0-47.4 pg m(-3) (median: 17.4 pg m(-3)) in PM2.5-10 in Datong. Of the PCB homologues, the dominant PCBs detected in the various media were all trichlorobiphenyls (tri-CBs). Moreover, the PCB distributions in PM2.5 and PM2.5-10 samples were quite different in the two cities. This may be caused by the differences of the industrial structures, and their relatively unintentional release of PCBs in these cities. Source analysis revealed that the major PCB contaminants in Linfen and Datong were tri-CBs and di-CBs, which were possibly associated with unintentional release of PCBs. Toxic equivalency concentrations based on ten dioxin-like PCBs ranged from 4.0×10(-5) to 2.3×10(-3) pgWHO-TEQ m(-3) in Linfen, and 4.5×10(-4) to 2.6×10(-4) pgWHO-TEQ m(-3) in Datong. The presence of PCB pollution is a potential threat to the residents of Datong and Linfen.

Special Distribution of Polybrominated Diphenyl Ethers in Brain Tissues of Free-range Domestic Hens and Ducks from a Village near an Electronic Waste Recycling Site in South China

The rural village, Taizhou of Zhejiang Province, had been exposed to e-waste recycling for years, the polybrominated diphenyl ether (PBDE) levels in hens and ducks were high. The concentration of ∑PBDEs in the brain was the lowest among tissues of individual hens and ducks after correction for the respective lipid content. Also, the concentration ratio of BDE-153 versus BDE-154 (153/154) of brain was the highest among tissues of individual hens and ducks. Our results indicate that the hindrance of blood–brain barrier to compounds, such as high molecular weight and non-planar conformation (steric hindrance), contributed to the low concentration of PBDEs in the brain tissue of hens and ducks, especially in cases exposed to high levels of PBDE.

The determination of chlorophenols in waste water by capillary zone electrophoresis with an organic modifier

SummaryAcapillary zone electrophoretic method has been optimized to improve selectivity and resolution in the analysis of chlorophenols in waste water. Use of a buffer system containing organic solvent dramatically improved the separation of chlorophenols. It was shown that selectivity was strongly affected by electrolyte pH and the presence of organic modifiers. The results show that the determination of all seventeen chlorinated derivatives of phenol in water can be achieved by use of a single organic modifier. For example, with acetone as organic modifier all 17 chlorophenols could be separated and determined within 20 min. The standard deviation of migration times and peak areas of the chlorophenols were in the ranges 0.48–0.67% and 3.9–5.1% respectively. Detection linear ranges covered two orders of magnitude of concentration with correlation coefficients of 0.998–1.000, except for 4-chlorophenol. Quantitative aspects of capillary zone electrophoresis are also discussed. It was concluded that capillary zone electrophoresis is a potential method for determination of chlorophenol pollutants in waste water.

Cryogenic properties of polymer composite materials — a review

Publisher Summary This chapter presents detailed discussions on the effects of various factors on the cryogenic mechanical and thermal properties at the unique operating environments. Polymer composite materials are used in a wide variety of cryogenic applications to replace metals because of their unique and highly tailorable properties. To develop high performance polymer composites for cryogenic applications, it is necessary to understand how polymer composites behave at cryogenic temperatures and how their cryogenic properties are affected by factors such as filler content and matrix type etc. Polymer composite materials are being increasingly employed to manufacture structural components that are exposed to low temperature environments in space and superconducting applications. The involved composites include fiber and particle reinforced thermoplastic and thermosetting polymer composites. The cryogenic applications of polymer composites can be classified as support structures, vessels, and electrical insulation. Fundamental mechanical, thermal, and electrical requirements should be met by polymer composites for specific cryogenic applications.

A new process for the preparation of polyimide/silica hybrid films

Publisher Summary This chapter introduces a new process to prepare a series of transparent PI/silica hybrid films. The PI/silica hybrid films possess lower coefficient of thermal expansion, higher thermal stability, and better mechanical properties at room temperature compared with neat PI films. However, the mechanical properties of PI/SiO2 hybrid films by the traditional process decreased fast by the addition of SiO2 particles at higher silica content because of the fast increase of particle size; moreover, few studies have been carried out on cryogenic properties of the PI/SiO2 hybrid films. The mechanical properties at 77 K of the films prepared by the new process have been studied. The morphology of the films has been characterized by scanning electron microscopy (SEM) observation. It is shown that the newly developed sol-gel process led to smaller silica particle sizes than the traditional sol-gel process did. The PI/SiO2 hybrid films prepared by the new process show better cryogenic mechanical properties than the hybrid films prepared by the traditional sol-gel process.

Measurement of the cryogenic tensile properties of polymer composites

Publisher Summary In this chapter, measurement of tensile strength, modulus and strain of polymer composites was conducted on a universal testing machine using self-designed tensile testing jigs at cryogenic temperature. The PI/MMT composite films were prepared via in-situ polymerization. The sizes of film specimens were respectively 10 mm × 90 mm (room temperature) and 10 mm × 120 mm (cryogenic temperature). The gauge length was 50 mm. The cryogenic tensile properties of nanofiller reinforced polymer composites have been studied as a function of filler contents and compared with that at room temperature. The results show that there exists an optimal filler content corresponding to the maximum strength and modulus. It is shown that the tensile strength and Youngs modulus of the polymer composites were generally higher at 77 K than that at room temperature except at the 20 wt % of clay for clay/polyimide nanocomposites. Moreover, the elongation to failure has much lower values at the cryogenic temperature (77 K) compared with that at room temperature.