No abstract

No abstract

No abstract

National legislation within Japan has increased the need for the development of new process technologies that will utilize waste wood materials. In order to generate some fundamental data with respect to the possible injection of such materials into blast furnaces, a study has been made of the decomposition and gasification reactions that take place when biomass material, in this case Japanese cypress chips, are exposed to temperatures between 1673 and 2073K using a high frequency induction furnace. The relative amounts of gas, char and tar were determined as well as the concentration of the various species present in the gas phase. The results obtained from gas analysis were in good agreement with values calculated from thermodynamic equilibria. Untersuchung Ober das Einblasen von Holzabfallen in denHochofen. Die nationale Gesetzgebung in Japan hat die Erfordernis verstarkt. neue Technologien zu entwickeln, die Holzabfallstoffe verwerten. Um grundlegende Oaten im Hinblick auf ein mogliches Einblasen solcher Stoffa in den Hochofen zu gewinnen, wurde eine Untersuchung Ober die Zerfalls-und Gasbildungsreaktionen durchgefOhrt, die stattfinden, wenn Biomasse, in diesem Fall Abfall aus japanischen Zypressen, in einem Hochfrequenz-lnduktionsofen Temperaturen zwischen 1673 und 2073 K ausgesetzt wird. Es wurden die relativen Mangen an Gas, Schwelkoks und Teer und die Konzentration der verschiedenen Gaskomponenten bestimmt. Die Ergebnisse aus der Gasanalyse stimmten gut mit Werten, die aus dem thermodynamischen Gleichgewicht berechnet wurden, Oberein.

National legislation within Japan has increased the need for the development of new process technologies that will utilise waste wood materials. The present study is aimed at generating some fundamental data with respect to the reduction of iron oxide by waste wood. By using a high frequency induction furnace, mixtures of wood + Fe203 were heated very rapidly to temperatures between 1673 and 2073K in a stream of argon. Gas chromatographic technique applied on exhaust gases escaping from the furnace revealed that the gaseous reaction products consisted mainly of carbon monoxide and hydrogen. On the other hand, conventional chemical analysis and X-ray diffraction technique made on condensed-phase reaction products detected the presence of Fe-C alloys, solid carbon (char) and ferrous oxide, depending upon the atomic ratio of C/O within wood + Fe 203 mixture. Thus, the reaction products consisted of metallic iron, ferrous oxide, char, CO, CO2, H 20, H 2 and CH4, depending upon C/O atomic ratio within the mixture and the experimental temperature. The results were in good agreement with values calculated from thermodynamic equilibrium.

The optimal temperature for anaerobic ammonium oxidation (anammox) is generally 30-37℃. This temperature range, which is higher than usual wastewater temperature, implies that the anammox reactor requires heat energy for efficient nitrogen removal. Therefore, the anammox process which is applicable at ambient temperature (20-25℃) is needed to develop more versatile and sustainable nitrogen removal technologies. This study was conducted to start-up lab-scale anammox reactors packed with a nonwoven fabric material at 20℃ using various inoculum sources. Reactor 1 was inoculated with activated sludge sampled in Kumamoto, a temperate region of Japan. Reactor 2 was inoculated with activated sludge obtained from Hokkaido, a subarctic region. Reactor 3 was inoculated with groundwater microorganisms sampled from Kumamoto. At 800 days from the start-up of the reactors, Reactors 1 and 2 achieved high nitrogen removal rates (NRR) of 0.64 kg-N/m 3 /day at 20℃ with the typical anammox reaction ratio. Although the nitrogen removal was unstable, the NRR increased to 0.38 kg-N/m 3 /day in Reactor 3 after 700 days. The nitrogen reaction ratio in Reactor 3 indicated the simultaneous occurrence of anammox and nitrification. Results suggest that anammox bacteria, which can grow at ambient temperature, are ubiquitous in the environment.

The single-stage nitrogen removal by anammox and partial nitritation (SNAP) process was evaluated for tolerances to fluctuations in pH (5.6 to 8.9), temperature (15 to 35 ℃), and dissolved oxygen (DO) concentration (2 to 5 mg/l ) using large-scale (80-l ) reactors. The nitrogen removal rate (NRR) increased with increases in DO concentrations up to 5 mg/l, indicating oxygen supply enhanced the specific activity of the ammonia-oxidizing bacteria (AOB) without inhibiting the anammox activity. Additionally, the NRR was stable at pH levels of 6.1 to 8.6; however, the NRR decreased at pH 5.6 with the occurrence of NH4 + -N accumulation due to a decrease in AOB activity, but was then quickly restored after adjusting the reactor pH to 7.5. Furthermore, the NRR decreased at pH levels over 8.9, as evidenced by increases in effluent NH4 + -N and NO2 --N concentrations; in this case, though, a long time was required to recover from this deleterious effect of pH on the core anammox activity. Finally, a high NRR could be maintained over a temperature range of 15 to 35 ℃, indicating the feasibility of the SNAP process over a substantial range of environmental conditions.

This paper analyzes historical trends of academic research on the water environment in Japan over the past 50 years in relation to societal circumstances by looking into 1470 articles published in a Japanese domestic journal during 1961–2010. We examined three components of the individual articles to substantiate the trends including “Visions”, “Target Water”, and “Objects”. The database of these components was first constructed, and then statistically analyzed. Principal components analyses revealed two historical turning points of the research trends, in 1970 and in the mid-1990s, showing first a clear transition of the main concern from industrial pollution to eutrophication, and later, a transition to global environmental issues. We also demonstrate that Visions and Target Water gradually diversified during the past 50 years, indicating that although the research activity in the early periods focused on serious pollution issues, more recently, the scope of water environmental studies expanded to various other issues along with the improvement in the quality of the water environment. We argue that academic research activity in Japan was conducted in close association with public concern and global movements in a timely and sensitive manner. Such knowledge could also provide implications to other nations facing serious water pollution.