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1.
Shigeki Uemura Akiyoshi Ohashi Hideki Harada Toshihiro Hoaki Takashi Tomozawa Takahiko Ohara Reiichi Ojima Tetsuya Ishida 《Waste management & research》2008,26(3):256-260
Inactivation of indigenous indicator micro-organisms such as faecal coliforms, coliphages, and faecal streptococci was investigated in a full-scale biogas plant that mainly digested cow manure. The biogas plant consisted principally of a feed reservoir, fermentation tank (37 degrees C), heat-inactivation process (70 degrees C), and five reservoirs for the heat-inactivated, digested manure that was used by a local livestock farmer as liquid fertilizer. Although all the indicators tended to exhibit stepwise decreases with each stage of treatment, coliphages were found to be more capable of surviving than faecal coliforms and faecal streptococci under mesophilic anaerobic conditions as well as high temperature conditions (heat-inactivation at 70 degrees C). Liquid fertilizer produced at the biogas plant had faecal coliform densities less than the stipulations of the US EPA 40 CFR 503 Class A limits. Heat-inactivation tests indicated that although coliphages exhibited more tolerance than other bacterial indicators between 37 and 70 degrees C, they were more sensitive to continuous temperature increase than faecal coliforms and faecal streptococci. 相似文献
2.
Ohara Toshiaki Yuasa Ken Kimura Kentaro Komaki Shiho Nishina Yuta Matsukawa Akihiro 《Journal of Material Cycles and Waste Management》2023,25(1):249-257
Journal of Material Cycles and Waste Management - Plant biomass could be a viable alternative renewable resource, but the moisture content must be reduced to use it as fuel. Mechanical compression... 相似文献
3.
Jun-ichi Kurokawa Keiya Yumimoto Itushi Uno Toshimasa Ohara 《Atmospheric environment (Oxford, England : 1994)》2009,43(11):1878-1887
A four-dimensional variational data assimilation system for optimization of NOx emissions (RC4-NOx) was developed. A parameterized NOx chemistry scheme was introduced into the RC4-NOx system, and key parameters such as chemical production and loss terms of NOx were calculated in advance using the Community Multiscale Air Quality (CMAQ) modeling system. RC4-NOx was applied to optimize NOx emissions over eastern China (EC) in July 1996, 1999, and 2002 using Global Ozone Monitoring Experiment (GOME) satellite observations of NO2 vertical column densities (VCDs) and a priori emissions from the Regional Emission Inventory in Asia (REAS). After assimilation, RC4-NOx generally reproduced the spatial distribution, regional averaged values, and time evolution of GOME NO2 VCDs. Over EC, a priori emissions were reduced by 20% in 1996 and by 8% in 1999, whereas a posteriori emissions were almost the same as a priori emissions in 2002. A priori emissions in the Beijing region were reduced by optimization over the whole simulation period. A posteriori emissions over the Yangtze Delta were larger than a priori emissions in 2002, although they were smaller in both 1996 and 1999. As in other areas, a priori emissions over the North China Plain were reduced in 1996; but those over the eastern part of the plain were increased in 1999, and the area of increased emissions moved slightly westward in 2002. In each region, the growth rates of a posteriori emissions during both 1996–1999 and 1999–2002 became generally larger than those of a priori emissions, and the trends of a posteriori emissions became similar to those of GOME NO2 VCDs. Our inverse modeling analysis indicates that the rate of increase of NOx emissions over EC from 1996 to 2002 was much larger for a posteriori emissions (49%) than for a priori emissions (19%). 相似文献
4.
Takashi Yamamoto Atsushi Ohara Yukio Noma Katsushi Nishizawa Akio Yasuhara Shin-ichi Sakai 《Journal of Material Cycles and Waste Management》2007,9(2):188-193
The photodegradation of tetraphenyltin (TePT) contained in polychlorinated biphenyl (PCB)-based transformer oil simulants
by ultraviolet (UV) irradiation in alkaline 2-propanol solutions was examined. In the absence of PCBs, the TePT level fell
to below 1% of the initial concentration within 30 min. In the absence of both PCBs and an alkali, the concentrations of tri-,
di-, and monophenyltins initially increased to a few milligrams per liter, and then reduced to below the detection limits
within 90 min. The addition of an alkali to the reaction solution slightly accelerated the photodecomposition of TePT. The
decomposition of other phenyltins (PTs) was also accelerated. When PCBs with concentrations of approximately 80 times the
initial TePT concentration were added, only a small fraction of the TePT decomposed within 100 min. Moreover, the levels of
PTs did not change during irradiation. TePT and other PTs did decompose when the level of PCBs was reduced to the same concentration
as that of TePT; however, the decomposition rates were slower than those in the absence of PCBs. In the actual treatment process,
TePT and other PTs in PCB-based transformer oil are decomposed by catalytic reduction, which is used after UV irradiation.
Therefore, in the actual treatment of PCB-based transformer oil wastes, pollution due to PTs can be prevented. 相似文献
5.
Isao Kanda Yukio Yamao Toshimasa Ohara Kiyoshi Uehara 《Environmental Modeling and Assessment》2013,18(2):221-248
This paper proposes an atmospheric diffusion model for traffic-related emission in urban areas within a few hundred meters from relevant roads. The model adopts the mass-conservation (MC) principle for the velocity calculation and the advection-diffusion (AD) equation for the concentration calculation. This MC+AD combination was chosen to achieve fast calculation for complex geometries. To compensate for the inherent deficiencies of MC and AD, as many known properties possible of turbulent boundary-layer flow over obstacles are incorporated into the MC calculation, and the diffusivity in AD is derived from the velocity spectrum as a function of distance from the emission source. The model is evaluated against wind-tunnel experiments ranging from point-source emission in uniform urban canopy to along-road emission in real city geometries. The model performs well in relatively simple configurations, but the performance deteriorates considerably as the complexity increases. However, in real city geometries, the model exhibits distinctly better performance in terms of statistical indices than a conventional Gaussian-plume model that neglects the effect of individual buildings. The model is therefore a viable option for environmental assessment. 相似文献
6.
7.
Regional-specific emission inventory for NH3, N2O, and CH4 via animal farming in South, Southeast, and East Asia 总被引:1,自引:0,他引:1
Kazuyo Yamaji Toshimasa Ohara Hajime Akimoto 《Atmospheric environment (Oxford, England : 1994)》2004,38(40):7111
Ammonia, nitrous oxide, and methane emission from animal farming of South, Southeast, and East Asia, in 2000, was estimated at about 4.7 Tg NH3–N, 0.51 Tg N2O–N, and 29.9 Tg CH4, respectively, using the FAO database and countries’ statistic databases as activity data, and emission factors taking account of regional characteristics. Most of these atmospheric components, up to 60–80%, were produced in China and India. Pakistan, Bangladesh, and Indonesia, which were large source countries next to China and India, contributed more than a few percent of total emission of each atmospheric component. The largest emission livestock were cattle whose contribution was considerably high in South, Southeast, and East Asia; more than one-fourth of ammonia and nitrous oxide emissions: more than half of methane emission. The other major livestock for nitrous oxide and ammonia emissions were pigs. For methane emission, buffaloes were second source livestock. To provide spatial distributions of these gases, the emissions of county and district level were allocated into each 0.5° grid by means of the weighting by high-resolution land cover datasets. The regions with considerable high emissions of all components were able to be found at the Ganges delta and the Yellow River basin. The spatial distributions for ammonia and nitrous oxide emissions were similar but had a substantial difference from methane distribution. 相似文献
8.
Kazuyo Yamaji Kohei Ikeda Hitoshi Irie Jun–ichi Kurokawa Toshimasa Ohara 《Journal of the Air & Waste Management Association (1995)》2014,64(4):436-444
NO2 vertical column densities (VCDs) over East Asia in June and December 2007 were simulated by the Community Multi-scale Air Quality (CMAQ) version 4.7.1 using an updated and more elaborate version of the Regional Emission Inventory in Asia (REAS) version 2. The modeling system could reasonably capture observed spatiotemporal changes of NO2 VCDs by satellite sensors, the Global Ozone Monitoring Experiment-2 (GOME-2), the Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY), and the Ozone Monitoring Instrument (OMI), even at the coarsest horizontal resolution of 80 km. The CMAQ simulations were performed in a sequence of three horizontal resolutions (80 km, 40 km, and 20 km) for June and December 2007 to investigate the influence of changes of horizontal resolution on the obtained NO2 VCDs. CMAQ-simulated NO2 VCDs generally increased with improvements in resolution from 80 km to 40 km and then to 20 km. Increases in the CMAQ-simulated NO2 VCDs were greater for the change from 80 km to 40 km than for those from 40 km and 20 km, in which the increases of NO2 VCDs due to the improvement of horizontal resolution were approached convergence at the horizontal resolution of approximately 20 km. Conversely, no clear convergences in NO2 VCDs changes were found at near Tokyo and over the East China Sea. The biases of the NO2 VCDs simulated at a resolution of 20 km against the satellite retrievals were ~36% near Beijing (CHN1) and ~78% near Shanghai (CHN2) in summer; these errors were found to be comparable to the horizontal resolution-dependent errors, which were 18–25% at CHN1 and 44–58% at CHN2 from 80 km to 40 km. Conversely, the influence of changes of horizontal resolution in winter was relatively less compared to that in summer.
Implications: NO2 VCDs over East Asia in June and December 2007 were simulated using CMAQ version 4.7.1 and REAS version 2. The modeling system could reasonably capture observed spatiotemporal changes of NO2 VCDs by satellite sensors. The CMAQ simulations were performed in a sequence of three horizontal resolutions, 80, 40, and 20 km, to investigate the influence of changes of horizontal resolution on the obtained NO2 VCDs. The results suggested that the influence of changes of horizontal resolution was larger in summer compared to that in winter. The magnitude of the influence was comparable to the biases of the NO2 VCDs simulated at a resolution of 20 km against the satellite retrievals. 相似文献
9.
Masahide Aikawa Toshimasa Ohara Takatoshi Hiraki Okihiro Oishi Akihiro Tsuji Makiko Yamagami Kentaro Murano Hitoshi Mukai 《Atmospheric environment (Oxford, England : 1994)》2010,44(3):381-391
We found a significant geographic gradient (longitudinal and latitudinal) in the sulfate (SO42?) concentrations measured at multiple sites over the East Asian Pacific Rim region. Furthermore, the observed gradient was well reproduced by a regional chemical transport model. The observed and modeled SO42? concentrations were higher at the sites closer to the Asian continent. The concentrations of SO42? from China as calculated by the model also showed the fundamental features of the longitudinal/latitudinal gradient. The proportional contribution of Chinese SO42? to the total in Japan throughout the year was above 50–70% in the control case, using data for Chinese sulfur dioxide (SO2) emission from the Regional Emission Inventory in Asia (40–60% in the low Chinese emissions case, using Chinese SO2 emissions data from the State Environmental Protection Administration of China), with a winter maximum of approximately 65–80%, although the actual concentrations of SO42? from China were highest in summer. The multiple-site measurements and the model analysis strongly suggest that the SO42? concentrations in Japan were influenced by the outflow from the Asian continent, and this influence was greatest in the areas closer to the Asian continent. In contrast, we found no longitudinal/latitudinal gradient in SO2 concentrations; instead SO2 concentrations were significantly correlated with local SO2 emissions. Our results show that large amounts of particulate sulfate are transported over long distances from the East Asian Pacific Rim region, and consequently the SO42? concentrations in Japan are controlled by the transboundary outflow from the Asian continent. 相似文献