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Volume 18, Issue 7
Displaying 1-10 of 10 articles from this issue
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Shinichi SAKAI, Hiroshi TAKATSUKI, Masakatsu HIRAOKA1989 Volume 18 Issue 7 Pages 397-405
Published: July 30, 1989
Released on J-STAGE: March 18, 2010
JOURNAL FREE ACCESSThe amount of asbestos wastes generation increases in future as the asbestos is recognized to be toxic and some abatement programs will be done. The asbestos wastes melting process was examined by means of X-ray diffraction, thermal analysis and scanning electron microscopy. It has been shown that a sprayed-on chrysotile asbestos decomposes in the region up to 800°C and melts around 1500°C to change into the slag, of which the main composition is magnesium silicate. And also asbestos fibers are shown to be disappeared in the melted slag. From these results the asbestos wastes melting process has the possibility that these wastes can be changed into the non-hazardous, non-carcinogenic material. Crocidolite and amosite wastes can also be melted into the slag around 1400°C. Three alternatives of asbestos wastes melting system are proposed; (1) the central treatment process, (2) the small portable melting process and (3) the co-melting process with other industrial wastes.View full abstractDownload PDF (2827K) -
Norimoto WATANABE, Masami KISHI1989 Volume 18 Issue 7 Pages 406-413
Published: July 30, 1989
Released on J-STAGE: March 18, 2010
JOURNAL FREE ACCESSRoad-Spray treatment using water extracts from withered leaf of oak was carried out during March 24th through April 10th in 1988. The samples of dust particles were collected at road edge from both zones on Road-Spray treatment and non-treatment. The objective of this research was to evaluate the Road-Spray treatment for removing heavy oil in road-dust orignated from asphalt. The heavy oil contents in road-dust samples were determind by three methods, i. e., IR-and UV-absorption spectrum and absorbancy at 370nm.
The heavy oil concentrations were lower for treated samples than that for non-treatment samples on all of particle size.
This trend was remarkably observed in the fractions below 105μm. That is, the heavy oil concentrations including three methods ranged from 0.13 to 8.86% for treatment samples, and from 0.26 to 11.22% for non-treatment.
Additionally, the removal values of liquid paraffin in contact with road-dust samples were determind by decreased rate of IR-absorption peak around wave numbers, i. e., 2920, 2850, 1460 and 1380cm-1, respectively.
Sum of removal values by four different wave numbers ranged from 39.1 to 44.0% for treated samples, and from 12.7 to 33.9% for non-treatment.
When compared with the removal of 2920cm-1 signal peculiar to B heavy oil, the values of treated samples was from 2.2 to 22.3 times greater than that for non-treatment in <105μm fractions.
These results suggest that Road-Spray treatment with extracts from withered leaf has marked effect on the degradation of asphalt oil in road-dust.View full abstractDownload PDF (942K) -
Soichiro NAKAMURA, Hisatake SHIROTA1989 Volume 18 Issue 7 Pages 414-417
Published: July 30, 1989
Released on J-STAGE: March 18, 2010
JOURNAL FREE ACCESSParticle fractions of 100-200, 10-100 and <10μm were separated from secondary effluents by plankton nets. Indigenous fecal coliforms associated with each particle size fraction were tested for their resistance to chlorine individually. Particle-associated fecal coliforms of the <10μm fraction were inactivated more rapidly by 0.5 and 1.0mg of chlorine per liter at 25°C and pH 7 than the other fractions. Contact times required for 99.9% inactivation of 0.5mg of chlorine per liter were over 3 -fold greater than the case of 1.0mg in each particle size fraction respectively. It is suggested that fecal coliforms associated with particle in actual secondary effluents have an aprotective effect against the disinfecting action of chlorine. And, it is demonstrated that many injured cells were yielded by chlorination in which are possible to rOcover in an adequate situation.View full abstractDownload PDF (599K) -
Akihiko HOGETSU, Hiroaki HIGASHINO, Shinichi NONAKA1989 Volume 18 Issue 7 Pages 418-423
Published: July 30, 1989
Released on J-STAGE: March 18, 2010
JOURNAL FREE ACCESSIndustrial wastewater sometimes contains a lot of sulfate or is neutralized by sulfuric acid. The effects of sulfate on methane fermentation were monitored in a fixed-bed anaerobic reactor by gradual increase of sulfate in influent wastewater.
Even at high sulfate concentration of 20000mg/l in influent water, continuous treatability test showed no inhibition to the TOC removal with more than 95% at TOC loading rate of 3 kg/m3·d.
The result was attributed to the facts that sulfate did not inhibit methanogenesis and that subject to the ratio of sulfur and carbon in the liquid, hydrogen sulfide did not increase in proportion to the increase of sulfate in influent water. Besides, keeping pH of the liquid at around 7 was another factor to maintain the unionized hydrogen sulfide at a low level.View full abstractDownload PDF (683K) -
Fumihiko JIKU1989 Volume 18 Issue 7 Pages 424-426
Published: July 30, 1989
Released on J-STAGE: March 18, 2010
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Hisashi YANO1989 Volume 18 Issue 7 Pages 427-433
Published: July 30, 1989
Released on J-STAGE: March 18, 2010
JOURNAL FREE ACCESSDownload PDF (883K) -
Koichi SOGA1989 Volume 18 Issue 7 Pages 434-438
Published: July 30, 1989
Released on J-STAGE: March 18, 2010
JOURNAL FREE ACCESSDownload PDF (701K) -
Takashi KORENAGA1989 Volume 18 Issue 7 Pages 439-444
Published: July 30, 1989
Released on J-STAGE: March 18, 2010
JOURNAL FREE ACCESSDownload PDF (884K) -
Tsutomu MIZUTANI1989 Volume 18 Issue 7 Pages 445-452
Published: July 30, 1989
Released on J-STAGE: March 18, 2010
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Nobuyuki HAYASHI1989 Volume 18 Issue 7 Pages 453-457
Published: July 30, 1989
Released on J-STAGE: March 18, 2010
JOURNAL FREE ACCESSDownload PDF (522K)
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