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541.
Liver alterations were stereologically determined in five groups, each of 10 male and female Sprague–Dawley weanling rats fed PCB 105 (2,3,3′,4,4′-pentachlorobiphenyl) for 13 weeks at concentrations of 0.05, 0.5, 5, and 50?ppm mixed with corn oil. Animals from two groups receiving the oil in diets served as controls for each gender. A significant increase in mean volume fraction (VF) of smooth endoplasmic reticulum (SER) profiles was estimated in hepatocytes of female rats in 0.5, 5, and 50?ppm groups. A significant decrease in VF of mitochondria in female rats at 50?ppm was detected. In addition, a decrease in VF of lipid droplets was measured in female rats at 0.5, 5, and 50?ppm groups. No difference was found in VF of rough endoplasmic reticulum (RER) cisternae, and peroxisome profiles at any concentration of the PCB in either male or female animals as compared to baseline values from controls. A significant elevation of baseline VF for RER in female rats was detected in comparison with males. In the present study, no observable adverse effect level (NOAEL) for PCB 105 was estimated at <0.5?ppm for hepatocyte alterations in female Sprague–Dawley rats. 相似文献
542.
Guor‐Cheng Fang Cheng‐Nan Chang Yuh‐Shen Wu Ding‐Guor Yang Chia‐Chium Chu 《毒物与环境化学》2013,95(3-4):341-355
Aerosol samples of particulate and chemical species for PM10 (particulate matter with aerodynamic diameters less than 10 μm) collected by Universal sampler were studied from June to August 1998 in the suburban area of central Taiwan. The ratios of PM2.5/PM2.5–10 displayed that the fine particles (particle size < 2.5 μm) are prevailing in the suburban site. Ion Chromatography was used to analyze for the water‐soluble ions: sulphate and nitrate in the Universal samples. Also, the collected samples were analyzed by atomic absorption spectrophotometry for the elemental analysis of Ca, Fe, Pb, Cu and Cr. The results indicated that the crustal elements (Ca and Fe) and resuspended matters were dominated in the coarse particulate mode while the anthropogenic elements (Cr, Pb, Cu) and sulphate components are mainly in the fine particle fraction. The results also showed that the sulphate and nitrate make the largest portion of the chemical species collected by Universal sampler (PMio). The concentrations of heavy metals in THU are generally high, owing to the higher motor vehicle and industrial density nearby. The degree of pollution from this source differs from day to day, depending on the motor vehicle density. 相似文献
543.
Experimental research on inhibition performances of the sand-suspended colloid for coal spontaneous combustion 总被引:1,自引:0,他引:1
Yong-liang Xu De-ming WangLan-yun Wang Xiao-xing ZhongTing-xiang Chu 《Safety Science》2012,50(4):822-827
Serious mine fire disasters have occurred in Northwest China where there are abundant coal resources. For the shortage of water and loess, a large cost of conventional grouting slurry is needed. However, plenty of sand and fly ash resources have been found there. In order to improve the quality of sand injection and reduce the wastage of water during grouting, a kind of new compound material of sand-suspended colloid, which is composed of mineral inorganic gel and organic polymer, was developed in this paper. And the inhibition performance experiments of the sand-suspended colloid were carried out. The results show that the sand-suspended colloid efficaciously affected the oxidation characteristics above the critical temperature during the acceleration oxidation of the lignite and fat-gas coal samples and restrained the oxidation course by increasing the activation energy, so that it reduced the contents of CO and C2H4 and depressed the oxidation rate during the coal spontaneous combustion, and finally inhibited the coal spontaneous combustion. 相似文献
544.
Lan-yun Wang Yong-liang Xu Shu-guang Jiang Ming-gao Yu Ting-xiang Chu Wei-qing Zhang Zheng-yan Wu Li-wen Kou 《Safety Science》2012,50(7):1528-1534
Low temperature oxidation of coal will result in coal spontaneous combustion in mined-out areas. We proposed to use ionic liquids to inhibit the coal spontaneous combustion in this paper. In order to study the inhibiting effect of ionic liquid (IL) on coal oxidation, we successfully dissolved bituminous coal samples in six kinds of imidazolium based ionic liquids, [AOEmim][BF4], [HOEmim][BF4], [Amim][Cl], [Emim][AC], [Bmim][AC] and [Bmim][OTf]. The functional groups in the coal samples pre-treated by different ILs were detected by Fourier Transform Infrared Spectroscopy (FTIR) in detail. It is found that the ILs are capable of breaking the associated hydroxyls into dissociated hydroxyls. And during the interaction between coal and ILs, the carboxyl groups have been created. Thermo Gravimetric experiment results show that the weight loss ratios of the IL-treated coals were less during 20–400 °C stage, compared with the IL-untreated coal, which indicates that most of the easily reductive groups effectively dissolved in the ionic liquids. According to the exothermic rate curves and the computed activation energy values, it is demonstrated that the [Bmim][OTf] and [Bmim][AC] make better effect than the other ILs for depressing the oxidation rate of bituminous coal. 相似文献
545.
Environmental catalysis also can refer to catalytic technologies for reducing emission of environmentally unacceptable compounds. Catalytic decomposition also is one of the cost-effective technologies to solve the troublesome volatile organic compounds. This study treated methyl isobutyl ketone (MIBK) by a commercial catalyst, Pt/gamma-Al(2)O(3), in an isothermal fixed bed differential reactor. The effects of O(2) and MIBK content in carrier gas on the catalysis's reaction rate are also observed. Three kinetic models, i.e. the Mars and van Krevelen model, Langmuir-Hinshelwood model and power-rate law were applied to best fit the experimental results. The results indicate that the kinetic behavior of MIBK oxidation with catalysis can be accounted for by using the rate expression of the Mars and van Krevelen model and Langmuir-Hinshelwood model. Kinetic parameters are also determined on the basis of the differential reactor data. The experimental results are compared with those of the model predicted. 相似文献
546.
Morphological changes in flocs were elucidated by small-angle light scattering, free settling tests and microscopic observation to determine the effects of pre-hydrolysis (alkaline treatment and ultrasonication) on two sludges--primary raw sludge from the Malabar Sewage Treatment Plant, Sydney (sludge M) and biological sludge collected at the nitrogen removal unit of St Marys Sewage Treatment Plant in Sydney (sludge S). Ultrasonication or alkaline treatment released a marked amount of insoluble organic matter in a soluble form. The latter treatment was more efficient than the former. Meanwhile, the pre-hydrolyzed flocs had more compact structures than the original ones, as shown by their higher free-settling fractal dimension, lower areal porosity and smaller internal pores. In particular, alkaline treatment yielded flocs with more compact interiors than did ultrasonication. Such detailed structural information could not be elicited by monitoring the change in floc size. The greater resistance to mass transfer of the hydrolyzed flocs thus produced does not reduce the efficiency of subsequent digestion, indicating that the surface reaction rate on the solid surface might have dominated since the pre-hydrolysis steps modified the local chemical environment to promote digestion. 相似文献
547.
Grease traps are widely used by most restaurants and food processing industries in Hong Kong to reduce oil and grease to an acceptable level before it can be discharged to public sewers. To meet demanding effluent standards in the future, it is necessary to polish the effluent by upgrading the conventional trap design. This study evaluated the possibility of upgrading traditional grease traps by installing tube settlers inside the trap. Their efficiency of removing chemical oxygen demand (COD) and oil/grease was examined to justify the performance. It was found that installing a tube settler is a feasible and cheap way to upgrade the conventional grease trap, since it improved oil/grease removal efficiency by 8-10% compared to the conventional design. In addition, a remarkable improvement in COD removal was observed following a very short hydraulic detention time after the installation of tube settlers. This ensured acceptable effluent quality under peak flowrates. Two mathematical models were also proposed to facilitate trap design. 相似文献
548.
ABSTRACT: A two-dimensional particle tracking model is developed for estuarine water quality investigation. The method requires only the solution of a two-dimensional hydrodynamics model and, therefore, is more economical to use than conventional multi-dimensional estuarine transport models. The present model does not consider turbulent diffusion, and it handles only conservative constituents. The model was applied to Humboldt Bay, California, where the flushing of sewage effluent was simulated. The model was applied to evaluate the present release plan, and to determine alternative release plans for limiting the transport of sewage effluent into shellfish producing areas Within the Bay. 相似文献
549.
Xiaona Chu Jiangyong Hu Say Leong Ong 《Frontiers of Environmental Science & Engineering in China》2009,3(4):393-403
Proteomics involves the separation of proteins, identification of the amino acid sequence of the interested or target proteins,
study of the function of the proteins, modification, structure and ultimate assignments to functional pathways in the cell.
The proteomic investigations have contributed greatly to human diseases studies, new drugs discovery researches, and environmental
science in recent years. This article provides a review on the development of the main proteomic technologies, including both
the gel based and non-gel based technologies, and their applications in environmental science. Proteomic technologies have
been utilized in the environmental stresses studies to analyze the induction or reduction of proteins at expression level
and identify the target proteins to investigate their function in response to environmental stresses, such as high or low
pH, oxidation stress, and toxic chemicals. Such protein responses are also helpful to understand the mechanisms of some cellular
activities and the functions of some proteins. 相似文献
550.