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1.
Hajime Yasuda Tohru Kamo Mariko Adachi Satoshi Sajima Hideki Nakagome 《Journal of Material Cycles and Waste Management》2010,12(2):123-127
The rapid hydropyrolysis of model compounds for epoxy resin oligomers and biomass tar was carried out in a hydrogen atmosphere
at 1073 K and 973 K. The assumed oligomers were partially pyrolyzed epoxy resin with biomass tar as solvent for the resin.
The product distributions obtained from rapid hydropyrolysis of phenol and bisphenol-A are shown. We also discuss the effects
of reaction temperature and hydrogen partial pressure on the product yield. In particular, more phenol was produced from bisphenol-A
at 973 K than at 1073 K. The yield of methane, which was the final hydropyrolysis product, increased with increasing hydrogen
partial pressure, whereas benzene and phenol were believed to behave as intermediate products in the hydropyrolysis reaction.
The results suggest that phenol could be obtained with high selectivity from tar by optimizing the reaction conditions. 相似文献
2.
Wastewater treatment with multilayer media of waste and natural indigenous materials 总被引:3,自引:0,他引:3
Rahman MA Ahsan S Kaneco S Katsumata H Suzuki T Ohta K 《Journal of environmental management》2005,74(2):107-110
Wastewater treatment using waste materials (refuse concrete, waste paper and charcoal) and natural indigenous rocks (andesite, limestone, granite and nitrolite) in the form of multilayer media was investigated. The removal of suspended solids (SS), phosphate ion, nitrate ion, ammonium ion, toxic metals and chemical oxygen demand (COD) were evaluated for the multilayer wastewater treatment system. Effective removal of heavy metals such as cadmium, chromium, mercury and lead was demonstrated. SS and phosphate ion were removed with relatively high efficiency and the COD after treatment was lessened using certain combinations of media. The present wastewater treatment system is simple, convenient and low cost. Therefore, this method can be applied in small scale plants for wastewater treatment in local and nonexclusive areas. 相似文献
3.
Hirakawa I Miyagawa S Katsu Y Kagami Y Tatarazako N Kobayashi T Kusano T Mizutani T Ogino Y Takeuchi T Ohta Y Iguchi T 《Chemosphere》2012,87(7):668-674
The occurrence of oocytes in the testis (testis-ova) of several fish species is often associated with exposure of estrogenic chemicals. However, induction mechanisms of the testis-ova remain to be elucidated. To develop marker genes for detecting testis-ova in the testis, adult male medaka were exposed to nominal concentration of 100 ng L−1 of 17α-ethinylestradiol (EE2) for 3-5 weeks, and 800 ng estradiol benzoate (EB) for 3 weeks (experiment I), and a measured concentration of 20 ng L−1 EE2 for 1-6 weeks (experiment II). Histological analysis was performed for the testis, and microarray analyses were performed for the testis, liver and brain. Microarray analysis in the estrogen-exposed medaka liver showed vitellogenin and choriogenin as estrogen responsive genes. Testis-ova were induced in the testis after 4 weeks of exposure to 100 ng L−1 EE2, 3 weeks of exposure to 800 ng EB, and 6 weeks of exposure to 20 ng L−1 EE2. Microarray analysis of estrogen-exposed testes revealed up-regulation of genes related to zona pellucida (ZP) and the oocytes marker gene, 42Sp50. Using quantitative RT-PCR we confirmed that Zpc5 gene can be used as a marker for the detection of testis-ova in male medaka. 相似文献
4.
Removal of organic polyelectrolytes and their metal complexes by adsorption onto xonotlite 总被引:1,自引:0,他引:1
Katsumata H Kaneco S Matsuno R Itoh K Masuyama K Suzuki T Funasaka K Ohta K 《Chemosphere》2003,52(5):909-915
Natural organic polyelectrolytes (humic and fulvic acids) and their metal complexes were removed by adsorption onto xonotlite. The removal percentages of humic and fulvic acids by xonotlite were approximately 80% and 30%, respectively. Humic acid removal from solution by adsorption onto xonotlite took place more readily than fulvic acid removal. The molecular weight distributions of the humic substances remaining in solution after adsorption with the xonotlite were measured with size exclusion chromatography. A comparison of molecular weight distributions demonstrated conclusively that large molecular weight components were adsorbed preferentially, indicating that adsorption efficiency depends on the number of functional groups of humic substances. Furthermore, the surface topography of the adsorbent was observed before and after adsorption by scanning electron microscopy. The calculated heat of adsorption was of 330 kJ mol(-1) which was evaluated from the Clapeyron-Clausius equation. Therefore, the adsorption type can be considered chemical. Since xonotlite can be easily synthesized and obtained at low cost, the adsorption method of humic and fulvic acids is superior to their precipitation. 相似文献
5.
A cost-effective method with zero valent iron (ZVI) powder was developed for the purification of thiobencarb (TB)-contaminated water. The removal treatment was performed in the batch system. A sample solution of 10 ml containing 10 microg ml(-1) of TB could be almost completely treated by 100mg of ZVI at 25 degrees C for 12h of treatment time. Since the formation of chloride ion in the aqueous solution during the treatment of TB was observed, the removal of TB with ZVI may contain two processes: reduction (degradation) and adsorption. Because the present treatment for TB is simple, easy handling and cheap, the developed technology with ZVI can contribute to the treatment of agricultural wastewaters. 相似文献
6.
DABWAN Ahmed H A IMAI Daizo KANECO Satoshi SENMATSU Isamu NAKAHAMA Katsuyuki KATSUMATA Hideyuki SUZUKI Tohru OHTA Kiyohisa 《环境科学学报(英文版)》2008,20(2)
A sintering technology for preparing porous materials from sea bottom sediments was developed for use in water purification. The purpose of the present study was to develop methods for converting the sea bottom sediments dredged from Ago Bay into value-added recycled products. The sintered products fabricated at 400℃ were found to be very effective adsorbents for the removal of heavy metals. 相似文献
7.
Kunichika Nakamiya Tohru Furuichi Kazuei Ishii 《Journal of Material Cycles and Waste Management》2002,4(2):127-134
This article reports the potential of denitrifying activated sludge to degrade highly chlorinated dioxins, especially from
a (landfill) leacheate treatment plant in Japan, and the isolation from this denitrifying activated sludge of a microorganism
able to degrade highly chlorinated dioxins. Using a 700-ml bioreactor, denitrifying activated sludge was cultivated under
denitrifying conditions by adding 2.0 ng of a mixture of 4- to 8-chlorinated dioxins from fly ash. The dioxin contents of
the sample, effluent, and medium before and after cultivation were measured by gas chromatography–mass spectrometry (GC–MS).
After 7 days cultivation, about 90% of added dioxins were lost (average percentage of isomer depletion). A dioxin-degrading
microorganism was isolated from the activated sludge. Lignin was added to the medium as a color indicator of aromatic compound
degradation, and the lignin-decolorizing microorganisms in the denitrifying activated sludge were screened. Some strains were
isolated, and one major isolated fungus, strain 622, decolorized lignin effectively. Strain 622 was identified as an Acremonium sp. from its morphological characteristics. It could decolorize lignin by 24% under paraffin-sealed anaerobic conditions.
After the cultivation of strain 622 with a 2 ng/ml mixture of 4- to 8-chlorinated dioxins for 1 day, 82% (average for individual
isomers) of the added 4- to 8-chlorinated dioxins had been degraded. Added octachlorodibenzo-p-dioxin (OCDD, 100 ng) was degraded under aerobic conditions after 8 h of incubation. During this process, heptachlorodibenzo-p-dioxin was produced and appeared to be a degradation product of OCDD. 1- or 2-hydroxydibenzo-p-dioxin from OCDD was also identified as the degradation product by GC–MS. These results indicated that OCDD was degraded
to the nonchlorinated dibenzo-p-dioxins through dechlorination by Acremonium sp. strain 622.
Received: October 12, 2001 / Accepted: March 11, 2002 相似文献
8.
Tohru Kamo Kanji Takaoka Junichiro Otomo Hiroshi Takahashi 《Journal of Material Cycles and Waste Management》2006,8(2):109-115
Steam gasification of dehydrochlorinated poly(vinyl chloride) (PVC) or activated carbon was carried out in the presence of
various alkali compounds at 3.0 MPa and 560°C–660°C in a batch reactor or in a semi-batch reactor with a flow of nitrogen
and steam. Hydrogen and sodium carbonate were the main products, and methane and carbon dioxide were the minor products. Yields
of hydrogen were high in the presence of sodium hydroxide and potassium hydroxide. The acceleration effect of the alkali compounds
on the gasification reaction was as follows: KOH > NaOH > Ca(OH)2 > Na2CO3. The rate of gasification increased with increasing partial steam pressure and NaOH/C molar ratio. However, the rate became
saturated at a molar ratio of NaOH/C greater than 2.0. 相似文献
9.
Evaluation of recycling policies for PET bottles based on multiattribute utility indices 总被引:1,自引:0,他引:1
This study focused on waste plastic, especially the polyethylene telephthalate (PET) bottle as representative waste, which
has been assigned as goods to be recycled by the Packaging Waste Recycling Law in Japan. We developed a plastic transport
model which explained the entire flow of plastic from the production stage to the disposal stage within an the evaluation
model of plastic recycle policy based on multiattribute utility theory. This model is designed to be used by local municipal
governments in supporting the evaluation of the PET bottle recycling policy. In evaluating the plastics recycling policy,
we selected indices relating to economy, ecology, and rate of resource recycling. The results indicate that when the evaluation
of the material recycling policy and thermal recycling policy in the model city were characterized in terms of their economic
and environmental aspects the thermal recycling policy had the highest utility within our scenario.
Received: July 31, 1998 / Accepted: January 26, 1999 相似文献
10.
Watanabe K Yokozeki K Ashizawa R Sakata N Morioka M Sakai E Daimon M 《Waste management (New York, N.Y.)》2006,26(7):752-757
Nuclear waste repositories need highly durable cementitious materials to function for over thousands of years while resisting leaching and degradation. The durability of cementitious material can be effectively improved by reducing permeability and by changing cement hydrates to a less soluble matrix. This paper describes the properties of carbonated new cementitious materials containing belite-rich cement and gamma-2CaO.SiO2 as main components. In addition, the long-term leaching properties are investigated and compared with ordinary Portland cement by using a predictive leaching model. 相似文献