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11.
The sonolytic degradation of alkylphenols (APs), such as butylphenol, pentylphenol, octylphenol, and nonylphenol (NP), in water was investigated at a sound frequency of 200 kHz with an acoustic intensity of 6 W cm(-2) under argon, oxygen, and air atmospheres. The sonolytic degradation rate of the APs under the conditions of the present study depended upon their alkyl chain length. The decrease in the degradation rate by the radical scavenging effect was in the range of about 48-82% for APs in the presence of 3 mM 2-methyl-2-propanol. The free radicals play a significant role in the sonolytic degradation process of the APs. In the presence of Fe(II) and Fe(III), the pseudo-first-order rate constants for the sonolytic degradation of 30 microM NP as a function of the concentration of Fe(II) and Fe(III) were estimated under argon and oxygen. The maximum rate constants were observed at 50 microM Fe(II) (0.139 +/- 0.008 min(-1)) and 100 microM Fe(III) (0.103 +/- 0.001 min(-1)) under oxygen. The total organic carbon concentration (TOC) was investigated under same conditions. TOC decreased in the range of about 50-70% during the sonication in the presence of Fe(II) and Fe(III) under argon and oxygen. The sonochemical effects by the addition of Fe(II) and Fe(III) as catalyst during the sonication under the proper atmosphere result in a remarkable enhancement of degradation and mineralization. 相似文献
12.
M. N. A. Bhuiyan Yasuaki Ito Toyoko Demachi Keizo Sugimoto Arata Katayama Tatsuya Hasegawa 《Journal of Material Cycles and Waste Management》2014,16(2):227-238
Hydrothermal treatment of model food garbage focusing on the effects of additional foreign matter has been performed in subcritical conditions as a pretreatment for the next step, i.e., the bio-processing and production of liquid feed or fertilizer. Using the hydrothermal technique, we studied the temporal change in internal temperature and pressure in a reactor on the elapsed heating time to check the equipment safety in terms of temperature and pressure. The gaseous and water-soluble liquid was also characterized to investigate the feasibility of retrieving valuable chemicals and emitting environmentally hazardous substances. From the changes in the internal temperature and pressure curve, the maximum temperature and pressure were 196 °C and 1.42 MPa for 30-min elapsed heating time, which was below the predefined temperature limits of 200 °C and pressure of 1.55 MPa. No such irregular behavior was observed in the temperature and pressure curve except that it was a little different for the foreign matter detergent, which also was within the limits. The qualitative and quantitative analysis of end products showed that the emitted malodorous substances and chemicals were further below the threshold levels for Japan. 相似文献
13.
Todaka T Hirakawa H Kajiwara J Hori T Tobiishi K Onozuka D Kato S Sasaki S Nakajima S Saijo Y Sata F Kishi R Iida T Furue M 《Chemosphere》2007,69(8):1228-1237
We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho coplanar polychlorinated biphenyls (non-ortho PCBs), and mono-ortho coplanar polychlorinated biphenyls (mono-ortho PCBs) in blood collected between 2002 and 2004 from 195 pregnant women living in Sapporo City of Hokkaido Prefecture, Japan. The present study is one of the few studies in which PCDDs, PCDFs, and dioxin-like PCBs have been measured in the blood of pregnant women. Of the 195 pregnant women, 101 were primipara (mean: 28.8 years) and 94 were multipara (mean: 32.4 years). The arithmetic mean total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs of primiparous and multiparous mothers in Sapporo City were 17.4 (median: 15.7) and 14.0 (median: 13.9)pgTEQ/glipid, respectively, and the concentrations were in the range of 6.6-43.4 and 3.4-28.2pgTEQ/glipid, respectively. In regard to the relationship between the total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in maternal blood and the number of deliveries or age of primiparous and multiparius mothers, the levels of these dioxin-like compounds tended to decrease with increases in the number of deliveries and significantly increased with increasing maternal age in both groups. Furthermore, significant correlations were observed between the total TEQ concentrations of these dioxin-like compounds and the age of primiparae and multiparae. The total TEQ concentration of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs measured in 195 pregnant women has decreased compared to past levels in Japan for the last several decades. The results of the present study have indicated that dioxin contamination in the blood of young women in Japan is continuing to decrease. 相似文献
14.
Parasites are ubiquitous in natural systems and ecosystem-level effects should be proportional to the amount of biomass or energy flow altered by the parasites. Here we quantified the extent to which a manipulative parasite altered the flow of energy through a forest-stream ecosystem. In a Japanese headwater stream, camel crickets and grasshoppers (Orthoptera) were 20 times more likely to enter a stream if infected by a nematomorph parasite (Gordionus spp.), corroborating evidence that nematomorphs manipulate their hosts to seek water where the parasites emerge as free-living adults. Endangered Japanese trout (Salvelinus leucomaenis japonicus) readily ate these infected orthopterans, which due to their abundance, accounted for 60% of the annual energy intake of the trout population. Trout grew fastest in the fall, when nematomorphs were driving energy-rich orthopterans into the stream. When infected orthopterans were available, trout did not eat benthic invertebrates in proportion to their abundance, leading to the potential for cascading, indirect effects through the forest-stream ecosystem. These results provide the first quantitative evidence that a manipulative parasite can dramatically alter the flow of energy through and across ecosystems. 相似文献
15.
Hikari Shimadera Hiroshi Hayami Satoru Chatani Yu Morino Yasuaki Mori Tazuko Morikawa 《Journal of the Air & Waste Management Association (1995)》2014,64(4):374-387
Improvement of air quality models is required so that they can be utilized to design effective control strategies for fine particulate matter (PM2.5). The Community Multiscale Air Quality modeling system was applied to the Greater Tokyo Area of Japan in winter 2010 and summer 2011. The model results were compared with observed concentrations of PM2.5 sulfate (SO42-), nitrate (NO3?) and ammonium, and gaseous nitric acid (HNO3) and ammonia (NH3). The model approximately reproduced PM2.5 SO42? concentration, but clearly overestimated PM2.5 NO3? concentration, which was attributed to overestimation of production of ammonium nitrate (NH4NO3). This study conducted sensitivity analyses of factors associated with the model performance for PM2.5 NO3? concentration, including temperature and relative humidity, emission of nitrogen oxides, seasonal variation of NH3 emission, HNO3 and NH3 dry deposition velocities, and heterogeneous reaction probability of dinitrogen pentoxide. Change in NH3 emission directly affected NH3 concentration, and substantially affected NH4NO3 concentration. Higher dry deposition velocities of HNO3 and NH3 led to substantial reductions of concentrations of the gaseous species and NH4NO3. Because uncertainties in NH3 emission and dry deposition processes are probably large, these processes may be key factors for improvement of the model performance for PM2.5 NO3?.
Implications: The Community Multiscale Air Quality modeling system clearly overestimated the concentration of fine particulate nitrate in the Greater Tokyo Area of Japan, which was attributed to overestimation of production of ammonium nitrate. Sensitivity analyses were conducted for factors associated with the model performance for nitrate. Ammonia emission and dry deposition of nitric acid and ammonia may be key factors for improvement of the model performance. 相似文献
16.
Ivan Nedjalkov Ryo Yoshiie Yasuaki Ueki Ichiro Naruse 《Journal of Material Cycles and Waste Management》2017,19(2):682-693
In this study we performed a non-isothermal thermogravimetric analysis on three thermoplastics—ABS, PC and PE. The Coats and Redfern method (Nature 201:68–69, 1964) was then used to approximate the kinetic parameters of each material. In addition, we performed a series of pyrolysis experiments in a batch reactor, for each plastic. The experiments were performed over the temperature range of 600–1000 °C at a constant residence time. The liquid and solid products of the pyrolysis, were collected, separated and weighted. Those products were categorized as soot, tar and char (PC only), and their relative weight to initial sample weight (DAF) was plotted against the temperature. The tar measured was exclusively medium to high molecular weight (>80 g/mol). Results revealed that relative tar and soot production, for all three materials, first increases and then decreases with temperature increase. The maximum achieved tar yields for ABS, PC and PE were at 700, 650 and 800 °C, respectively; and the maximum soot yields were at 1000, 1000, 950 °C, respectively. 相似文献
17.
Yasuaki Hijioka Saneyuki Takano Kazutaka Oka Minoru Yoshikawa Arata Ichihashi Kenshi Baba Sawako Ishiwatari 《Regional Environmental Change》2016,16(4):967-978
The impacts of climate change are apparent in various regions of the world. Even though climate change may have a positive effect, it is anticipated that there will be many severely negative effects on human and natural resources in the future. Therefore, in addition to the need for stronger promotion of mitigation policies, it is urgently necessary to study and implement adaptation policies over the longer term to prepare for the possible negative impact of climate change. To implement climate change adaptation measures rapidly in Japan, it would seem practical and effective to make good use of the various countermeasures already promoted by both the national and the local governments for many sectors such as disaster prevention, environmental management, food production, and protection of the nation’s health. These countermeasures are considered to have potential for effecting climate change adaptation. This study, focusing on adaptation to climate change negative impacts, investigates to what extent the existing policies of the Tokyo Metropolitan Government could contribute to climate change adaptation, based on a comprehensive examination of targeted fields and indicators for which adaptation policies could be pursued. The results showed many of the existing policies could be useful for adaptation to climate change in many sectors. Furthermore, less than half of these policies need to take future climate change into account in order to contribute to climate change adaptation. This study proposes three basic steps that consider future climate change and local governmental propositions for the rapid implementation of adaptation policies in Japan. 相似文献