Journal of Japan Society on Water Environment
Online ISSN : 1881-3690
Print ISSN : 0916-8958
ISSN-L : 0916-8958
Volume 19, Issue 5
Displaying 1-6 of 6 articles from this issue
ORIGINALS
  • Young Sik LEE, Tetsuo MUKAI, Kazuto TAKIMOTO, Mitsumasa OKADA
    1996 Volume 19 Issue 5 Pages 373-380
    Published: May 10, 1996
    Released on J-STAGE: January 22, 2008
    JOURNAL FREE ACCESS
    Indigenous phytoplankton assemblage was used in algal assay procedure to estimate limiting nutrient for phytoplankton growth in marine water. Algal assays were also conducted using size-fractionated indigenous phytoplankton, i.e., microphytoplankton, nanophytoplankton, and picophytoplankton to identify the difference in limiting nutrient among phytoplankton species of different size. Specific conclusions derived from this study are as follows;
    1) Indigenous phytoplankton assemblage could be used for algal assay to estimate limiting nutrient for phytoplankton growth.
    2) There was the difference in limiting nutrient for phytoplankton growth between conventional algal assay procedure with Heterosigma akashiwo and the present method with indigenous phytoplankton community.
    3) Growth of both microphytoplankton and nanophytoplankton was limited by nitrogen, whereas picophytoplankton was limited by phosphorus despite the same seawater sample.
    4) It was possible to estimate the limiting nutrient for microphytoplankton, nanophytoplankton and picophytoplankton even in case of inoculation density equivalent to Kuroshio water or conventional algal assay procedure.
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  • Koji TOSA, Tsuyoshi HIRATA, Katsuhisa TAGUCHI
    1996 Volume 19 Issue 5 Pages 381-387
    Published: May 10, 1996
    Released on J-STAGE: January 22, 2008
    JOURNAL FREE ACCESS
    Many researchers have studied the injury of enteropathogenic bacteria in water induced by chlorine, but there have been little research on the injury induced by chloramine. The purpose of this study is to compare the injuries of enterotoxigenic Escherichia coli induced by chloramine and by free chlorine. The injury was assessed by determining the difference between the number of CFU on nonselective TSA and the number of CFU on selective TSA supplemented with 0.02% sodium deoxycholate. The results can be summarized as follows: 1) Chlorine injury increased with contact time and almost all of surviving cells were injured finally, while chloramine injury increased with contact time and a considerable number of surviving cells were not injured. 2) Chlorine injury can be described by two-hit model assuming that injury is caused by one-hit, while chloramine injury appears to be described by a modified two-hit model considering inactivation of injured cells independent of chloramine concentration. 3) The presented models showed that chlorine injury is always larger than chloramine injury when compared at the same survival ratio, and that a combination of low chloramine concentration and long contact time is more effective than a combination of high chloramine concentration and short contact time.
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  • Yoshihiro SUZUKI, Toshiro MARUYAMA, Tohru TAKAMI, Yutaka DOTE
    1996 Volume 19 Issue 5 Pages 388-396
    Published: May 10, 1996
    Released on J-STAGE: January 22, 2008
    JOURNAL FREE ACCESS
    Monochloramine (NH2Cl) is the strongest toxic substance resulting from chlorinated sewage effluent. To estimate of NH2Cl on the growth of organisms in coastal region, disappearance of NH2Cl in seawater was investigated.
    Changes concentration of NH2Cl and total oxidant in artificial seawater were determined. The concentration of NH2Cl decreased with time and reached to 20% of the initial concentration after 6 hour at 30°C. On the other hand, 90% of the initial concentration of total oxidant was detected after disappearance of NH2Cl. The rate constant of NH2Cl disappearance was not concerned in the initial concentration at constant temperature. Disappearance of NH2Cl depended on water temperature, and the rate constant followed the Arrhenius equation. The rate constant and half-life value at 20°C for NH2Cl in seawater were 0.031 h-1 and 10 h. These results suggested that the effluent contained NH2Cl would be enough to effect on coastal organism until its disappearance. NH2Cl disappearance depended on salinity. However, NH2Cl in artificial seawater without KBr was stable even in the same condition. It was clear that the disappearance factor of NH2Cl was in existence of Br-. NH2Cl changed to the other oxidant with Br-, therefore, the product which may act on organisms still remained in seawater after disappearance of NH2Cl.
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  • Katsuhiko NAKAMURO, Masanobu IRIGUCHI, Mieko HAYASHI, Yasuyoshi SAYATO
    1996 Volume 19 Issue 5 Pages 397-404
    Published: May 10, 1996
    Released on J-STAGE: January 22, 2008
    JOURNAL FREE ACCESS
    The formation of by-products during aqueous ozonation of aniline in the presence of inorganic nitrogen compounds such as ammonium ion, nitrate or nitrite was investigated. During aqueous ozonation of aniline without inorganic nitrogen compounds, the major by-products determined quantitatively were nitrosobenzene, nitrobenzene, o-nitroaniline and m-nitroaniline.
    By interaction of aniline with nitrite, nitrosobenzene, nitrobenzene, o-nitroaniline and p-nitroaniline were formed. It was recognized that the detectable reaction by-products during aqueous ozonation of aniline in the presence of nitrite were nitrosobenzene, nitrobenzene, o-, m-, p-nitroaniline, 1,2-dinitrobenzene, 1,4-dinitrobenzene and 2,4-dinitroaniline.
    Especially, p-nitroaniline was formed only by the interaction of aniline with nitrite.
    This study proposed the possible mechanism of by-products during aqueous ozonation of aniline in the presence of nitrite.
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NOTES
  • Young Sik LEE, Tohru SEIKI, Tetsuo MUKAI, Kazuto TAKIMOTO, Mitsumasa O ...
    1996 Volume 19 Issue 5 Pages 405-411
    Published: May 10, 1996
    Released on J-STAGE: January 22, 2008
    JOURNAL FREE ACCESS
    Seasonal variations in chlorophyll a and cell density of micro-, nano-, and picophytoplankton were studied in northern part of eutrophic Hiroshima Bay to estimate the contribution of each size phytoplankton to total phytoplankton biomass and cell density. The highest percentages of micro- and nanophytoplankton to total chlorophyll a was observed during winter to spring and summer to autumn, respectively. However, percentage of picophytoplankton to total chlorophyll a showed little variation throughout the year. During January to April and June to August, nanophytoplankton alone or micro- and nanophytoplankton were dominant accounting for 50-90% of total cell density in every year. However, in other months, picophytoplankton accounted for 50-95% of total cell density. Picocyanobacteria were the dominant component of picophytoplankton community during the whole year, and the important contributor to total phytoplankton cell density in Hiroshima Bay. Chlorophyll a concentration of nanophytoplankton increased when NO3-N concentration increased with the inflow of river water due to rainfall. Chlorophyll a concentration of picophytoplankton increased with the decrease in NO3-N by the growth of nanophytoplanlton.
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  • Sanae YOSHIKAWA, Yuhei INAMORI, Akiko UTSUNOMIYA, Mitsumasa OKADA, Mik ...
    1996 Volume 19 Issue 5 Pages 412-416
    Published: May 10, 1996
    Released on J-STAGE: January 22, 2008
    JOURNAL FREE ACCESS
    Determination of BOD, COD, TOC, T-N and T-P in the homemade- and market-soap were performed by 6 laboratories to examine analytical precision and to know organic pollutant loads. Coefficient of variance of measurements for BOD, COD and TOC was 3 to 27%, 6 to 38%, 2.7 to 17%, respectively. These results indicated that there were no significant among them. The organic pollutant load of pudding like soap per dryness weight were similar those solid soap. The load of powder soap made in miniplant was lowest value. The difference of BOD per organic substance unitweight was not found in the method of process and shape of soap. Each load of T-N and T-P was negligible level.
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