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41.
Study on dechlorination technology for municipal waste plastics containing polyvinyl chloride and polyethylene terephthalate 总被引:1,自引:1,他引:0
Masaaki Fukushima Beili Wu Hidetoshi Ibe Keiji Wakai Eiichi Sugiyama Hironobu Abe Kiyohiko Kitagawa Shigenori Tsuruga Katsumi Shimura Eiichi Ono 《Journal of Material Cycles and Waste Management》2010,12(2):108-122
It is necessary to remove chlorine efficiently from municipal waste plastics (MWP) that contain polyvinyl chloride (PVC) and
other plastics containing chlorine. In this article we consider thermal degradation liquefaction technology. In Japan, the
chlorine content of reclamation oil products must be kept below 100 ppm owing to the quality standard for pyrolysis oil. Liquefaction
dechlorination technology for MWP is still an important issue to study. The twin-screw extruder that has been developed as
dechlorination technology for blast furnaces and coke ovens has a shorter residence time for dechlorination than other dechlorination
technologies. In this article, we used a single-screw extruder for the dechlorination process because it also has a short
residence time. Experiments on the dechlorination process were carried out by using a single-screw extruder to assess its
dechlorination performance. Practical use of the single-screw was demonstrated by the operation of a commercial oil reclamation
plant operated by Sapporo Plastic Recycle Co., Ltd. (SPR). Moreover, an investigation of cascade recycling was carried out
in 2008 in which material recycle wastes were mixed with MWP and processed by chemical recycling (liquefaction). It was demonstrated
that cascade recycling is an efficient recycling combination and contributes to local feedstock recycling. However, it was
shown that MR wastes affect the quality of the reclamation oil when they make up more than 40% of the feed mix. If the quantity
of MR wastes is kept below 40%, the reclamation oil is able to meet the quality standard. The SPR plant can be operated safely
and in a stable manner. 相似文献
42.
43.
Sato E Shibata K Wu YX Uezato T Kobayashi K Miura N 《Journal of environmental biology / Academy of Environmental Biology, India》2003,24(1):39-43
Skin darkened tadpoles sometimes appear spontaneously. Darkened was artificially induced in Xenopus larvae by yohimbine or chlorpromazine. These phenomena look like that are seen at pinealectomized or hypothalamus separated Xenopus larva. In this experiment, such a morphological color changed Xenopus larva is suggested by cause of inhibition of alpha2-adrenargic receptor or dopamine receptor from gastrula stages. 相似文献
44.
Yasuhito Igarashi Yayoi Inomata Michio Aoyama Katsumi Hirose Hiroshi Takahashi Yoshihiro Shinoda Nobuo Sugimoto Atsushi Shimizu Masaru Chiba 《Atmospheric environment (Oxford, England : 1994)》2009,43(18):2971-2980
Decades-long monitoring of anthropogenic radionuclides in the atmospheric deposition in Tsukuba, Japan suggests not only the substantial impacts of the Asian dust (Kosa) on the deposition but also the possible change of the Kosa source region, especially during springs of the 2000s. In order to know more about such change, 4 single wet deposition events occurred in the spring of 2007 were scrutinized. The largest anthropogenic radionuclides wet deposition was supplied by the April 2–4 event. It brought several tens % of the monthly depositions (April 2007) of the dust (residue) mass (4.5 g m?2) and anthropogenic radionulides (90Sr: 16, 137Cs: 97 and Pu: 3 mBq m?2). None of the events observed fulfilled both criteria of the specific activities and 90Sr/137Cs activity ratio to the Tsukuba soil; they did not exhibit local soil dust signature. The Kosa events in fact have extensive impacts on the atmospheric environment over Japan in spring season. Considering the elevated specific activities as well as greater 137Cs/90Sr activity ratio in the deposited dust, it is hypothesized that the dust source areas in Asian continent would be shifting from the arid zone to the desert-steppe zone suffering from desertification during the 2000s. This type of the Kosa may be called as the ‘new-regime Kosa’. Chemical observation in the far downwind region of the Kosa dust could allow us to know possible shift in the source regions. 相似文献
45.
The recycling of waste plastics that include plastics that contain chlorine, such as polyvinyl chloride, is difficult because the chlorine leads to the corrosion of equipment. Then, the dechlorination method of waste plastics containing chlorine (CCWP) that consists of a series of melt process and hot water process was examined. CCWP was put into the melt process with coal tar (HOB) and converter dust (CD) to inhibit the diffusion of the chlorine-containing gas. The results indicated that iron oxide of the principal element of CD combines with chlorine eliminated from CCWP, and forms water-soluble iron chloride on the melt process. HOB dissolves or adsorbs a part of the chlorine during the melt process, and inhibits the diffusion of the chlorine-containing gas. Approximately 98% of the chlorine in the CCWP reacts with CD and forms iron chloride, which can be extracted on the hot water process. 相似文献
46.
Saitoh Katsumi Kawabata Shin-ichirou Shirai Tadashi Sato Tatsuji Odaka Matsuo 《Water, Air, & Soil Pollution: Focus》2003,3(5-6):173-180
PM2.5 and PM10 samples for megalopolis atmospheric particles were collected at Shinjuku, Tokyo in December 1998–January 1999 and August 1999, for two weeks both in winter and summer, with a 24 hr sampling interval. Sampling of PM2.5 and PM10 in diesel exhaust particles (DEP) was carried out using an automobile exhaust testing system, with a diesel truck placed on a chassis dynamometer. Sampling conditions included idling, constant speed of 40 km hr-1, M-15 test pattern and 60%-revolution/40%-load of maximum power. Mass spectrums of organic compounds adhering to the surface of the PM2.5 and PM10 samples were analyzed by laser desorption time-of-flight mass spectrometry (LD-TOFMS, analytical mass range: m/z 1–m/z 380 000). LD-TOFMS analysis of those samples revealed consistently the detection of low-mass organic compounds up to m/z 800. For the megalopolis atmospheric particles, the mass spectrum pattern of wintertime samples was almost the same as that of the summertime samples for both PM2.5 and PM10. The major peak was m/z 177, and the minor peaks were m/z 84, 94, 101, 163, 189 and 235. The mass spectrum pattern of DEP was the same for all samples under all test conditions. The major peak was m/z 101, and other detected peaks were small. 相似文献
47.
Yasuhito Igarashi Michio Aoyama Katsumi Hirose Pavel Povinec Sadayo Yabuki 《Water, Air, & Soil Pollution: Focus》2005,5(3-6):51-69
Currently, atmospheric anthropogenic radionuclides (particulate) are controlled by suspension of the surface dust containing
those radionuclides (resuspension). We have found, therefore, that such radionuclides can be used as tracers of the surface
dust suspension, transport and its subsequent deposition in distant areas. The 137Cs/90Sr activity ratios in the atmospheric deposition, without the direct influence of nuclear tests and accidents, at the Meteorological
Research Institute (MRI, Tsukuba, Japan) during the 1990s were fairly low (average: 2.1). This value is not in agreement with
the ratios in Japanese surface soils (range of averages: 4–7), which had been considered as the primary source of the deposited
dust. This suggests that the current atmospheric dust deposition in Japan is a mixture of local and remote components. The
remote component could be an aeolian dust that has been transported long distances from arid areas. The major component is
most likely to be Asian dust. It was further hypothesized that other remote source may exist beyond the Asian domain, based
on accumulated observations and model results. To obtain more information about the dust transport, Sahara dust deposited
in Monaco in 2002 and a suspended dust collected in the Taklamakan area in 2001 were analyzed for 90Sr and 137Cs. The Taklamakan dust exhibited a 137Cs/90Sr ratio of about 4, which is within the range of atmospheric deposition observed at the MRI, while the Sahara dust exhibited
a higher 137Cs/90Sr ratio (about 13). Although the present Sahara datum was negative for our hypothesis of ‘hyper-range transport’, the seasonal
change of the 137Cs/90Sr ratio in the atmospheric deposition observed at the MRI requires an aeolian dust source having a low 137Cs/90Sr ratio, other than Asian dust. 相似文献
48.
Hirose K Igarashi Y Aoyama M Kim CK Kim CS Chang BW 《Journal of environmental monitoring : JEM》2003,5(2):302-307
Plutonium in monthly deposition samples collected in Tsukuba (the Meteorological Research Institute), Japan from 1990 to end of 2001 is reported, together with monthly plutonium deposition in Nagasaki and Yonaguni in 2000. The annual deposition of (239,240)Pu during the period from 1990 to 2001 shows no systematic interannual variation. However, monthly (239,240)Pu depositions show a typical seasonal variation with a maximum in spring season (March to April), which corresponds to seasonal cycle of soil dusts originating from the East Asian arid area. Plutonium isotopic ratios in the deposition samples suggest that significant amounts of the recent (239,240)Pu deposition observed in Japan are attributed to the resuspension of plutonium-bearing surface soil particles; resuspended plutonium originates from the East Asian arid areas. The recent increased tendency of (239,240)Pu content in residues in deposition samples may reflect desertification in the East Asian continent. 相似文献
49.
Kobayashi K Pillai KS Guhatakurta S Cherian KM Ohnishi M 《Journal of environmental biology / Academy of Environmental Biology, India》2011,32(1):11-16
In the present study, an attempt was made to compare the statistical tools used for analysing the data of repeated dose toxicity studies with rodents conducted in 45 countries, with that of Japan. The study revealed that there was no congruence among the countries in the use of statistical tools for analysing the data obtained from the above studies. For example, to analyse the data obtained from repeated dose toxicity studies with rodents, Scheffé's multiple range and Dunnett type (joint type Dunnett) tests are commonly used in Japan, but in other countries use of these statistical tools is not so common. However, statistical techniques used for testing the above data for homogeneity of variance and inter-group comparisons do not differ much between Japan and other countries. In Japan, the data are generally not tested for normality and the same is true with the most of the countries investigated. In the present investigation, out of 127 studies examined, data of only 6 studies were analysed for both homogeneity of variance and normal distribution. For examining homogeneity of variance, we propose Levene's test, since the commonly used Bartlett's test may show heterogeneity in variance in all the groups, if a slight heterogeneity in variance is seen any one of the groups. We suggest the data may be examined for both homogeneity of variance and normal distribution. For the data of the groups that do not show heterogeneity of variance, to find the significant difference among the groups, we recommend Dunnett's test, and for those show heterogeneity of variance, we recommend Steel's test. 相似文献
50.
Sarmah Purbashree Ishiguro Takeshi Maruyama Kenji Xue Tianle Yamawaki Atsushi Katsumi Takeshi Takai Atsushi Omine Kiyoshi Doi Yoichi 《Journal of Material Cycles and Waste Management》2022,24(6):2183-2200
Journal of Material Cycles and Waste Management - Mechanical properties and slope stability of inert waste landfills under seismic condition were studied with three different approaches: in-situ... 相似文献