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211.
Assessment of contaminant releases during utilization of used oils is essential for the determination of environmental acceptability. These paper reports the results of the study examining a toxic metal leachability from used engine oil and sludge samples employing leaching test (TCLP). The leaching test indicated that lead in oil samples exceeded 5-ppm concentration level what qualified them as a toxic waste. The samples of contaminated sludge were found to contain high concentration of total lead, barium and chromium, but the leaching test showed concentration below regulatory limit. The total content of benzene, ethylbenzene, toluene, and xylenes (BETX), and naphthalene in used oil and sludge samples was also determined and was found not to be a significant factor to contamination. 相似文献
212.
磷酸浓缩氟吸收问题的探讨 总被引:1,自引:0,他引:1
将我国现有的几种磷酸浓缩流程和实际应用效果进行比较 ,并从氟吸收机理分析探讨氟吸收级数与吸收效率的关系 ;氟硅酸浓度、温度与吸收效率的关系 ;吸收设备和雾沫分离器选型等 相似文献
213.
研制一种由醋酸乙烯、丙烯酸丁酯、特种单体共聚而成的水性交联型环保胶粘剂以替代目前广泛使用的氨基树脂,适应绿色环保要求。 相似文献
214.
The solubility parameter of poly(ethylene oxide) at 25°C has been determined using the method developed by DiPaola-Baranyi and Guillet, by the extrapolation of the values of the interaction parameter χ, at high temperatures, ranging from 70°–90°, 90°–110° and 110°–130°C down to 25°C. The values of the solubility parameter obtained, depending on the temperature ranges employed, are 9.8, 9.9 and 10.1, respectively. 相似文献
215.
A suite of density-differentiated macerals from several coals was analysed by Fourier transform infrared spectroscopy to obtain information on the nature and magnitude of the variations exhibited by the various maceral fractions. The most characteristic change between maceral groups was the variation in aliphatic hydrogen content, with exinite ? vitrinite ? inertinite. Since the separation technique (density gradient centrifugation) generally provided a number of fractions within a maceral group region, some of these were also analysed. In a series of density fractions from a low rank vitrinite, it was found that the aliphatic hydrogen content decreased as the density increased. The inertinites also exhibited a decrease in aliphatic hydrogen. The inertinite C—O bands had extinction coefficients different from those of vitrinites or exinites. The data suggest that quite profound variations in organic structure as determined by FT-i.r. spectroscopy can exist within a maceral group, so that for the most critical work on coals it is necessary to take this into account. 相似文献
216.
57Fe Mössbauer spectroscopy has been used to characterize the iron-bearing minerals present in some British Columbia coals. The minerals observed in a range of samples include pyrite/marcasite, siderite, jarosite, rozenite or melanterite, and Fe2+ -bearing clay minerals such as illite. The presence of jarosite is confirmed through the magnetic hyperfine interaction observed at 4.2 K. The absence of magnetic ordering at 4.2 K for the ferrous sulphate component indicates the presence of rozenite, FeS04 · 4H20, or melanterite, FeS04 · 7H20, rather than szomolnokite, FeS04 · H20 or FeS04. The effects of ashing on two of the coals is also studied. 相似文献
217.
Bituminous coal samples from 84 distinct sources were analysed by conventional British Standards (BS) methods for phosphorus, sulphur, chlorine, ash and the ash-forming elements (calcium, silicon, aluminium, iron, sodium, magnesium, potassium, titanium and manganese). In most cases four determinations were made per element per source. Samples were crushed to ?212 μm (72 BS mesh) and pressed into aluminium cups at 20 t in?2 (309 MPa) without binder or backing. Two pellets from each sample were analysed by wave-length dispersive X-ray fluorescence techniques, using a spectrometer equipped with a rhodium rube; the X-ray count took 60 s. The X-ray results were calibrated against the conventional results using multiple regression. The accuracy obtained was comparable with routine ‘wet chemical’ techniques. The X-ray technique is suitable for the routine determination of large numbers of samples. 相似文献
218.
Abstract. For stationary second-order autoregressive normal processes, the conjecture of uniqueness of the solution of the exact likelihood equations is examined. A sufficient condition for uniqueness is given; this condition is satisfied with very high probability if the number of observations is not extremely small. Moreover, it is shown that not more than two maxima may exist. Examples of data which actually produce a likelihood function with two local maxima are given. 相似文献
219.
F. Bianchi S. Cantagallo G. Consolati M. Laporta M. Pegoraro G. Tieghi L. Zanderighi 《应用聚合物科学杂志》2002,86(3):559-571
Four production steps, extrusion, blowing, stabilization, and finishing, are involved in the manufacture of biorented nylon 6 films. The films obtained after each step were studied by wide‐angle diffraction X‐rays, IR analysis, and density measurements. Orientation in the amorphous phase was evaluated by thermal retraction. Free volume was investigated by positron annihilation spectroscopy. Mechanical properties were tested by tensile tests, and permeability was tested with isopiestic permeameters. Quenching, after extrusion, generated an unstable γ crystalline phase and an amorphous phase. Blowing transformed the unstable γ phase into the thermodynamically stable α phase and increased the chain orientation; stabilization increased α phase crystals, favored hydrogen bond formation and, therefore, the mechanical properties, leaving unchanged the chain orientation; the final treatment increased the mechanical properties. The film permeabilities to O2, N2, and CO2 were practically unchanged after each production step; this result may be explained by considering that the nanoholes, present in the films and responsible for the diffusion inside the polymer, maintained practically constant their radius, whereas their number concentration decreased slowly after thermomechanical treatments. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 559–571, 2002 相似文献
220.
在介绍循环经济的内涵和发展的基础上 ,结合辽宁省的环境问题 ,提出了只有通过大力发展循环经济 ,才能尽快解决辽宁省的结构性、区域性环境污染问题 相似文献