Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research)
Online ISSN : 2185-6648
ISSN-L : 2185-6648
Volume 77, Issue 4
Displaying 1-3 of 3 articles from this issue
Paper (In Japanese)
  • Naoyuki YAMASHITA, Yukako KUROSE, Hiroaki TANAKA, Kentaro KOBAYASHI, H ...
    2021 Volume 77 Issue 4 Pages 112-121
    Published: 2021
    Released on J-STAGE: October 20, 2021
    JOURNAL FREE ACCESS

     This study investigated the occurrence of pharmaceuticals at a wastewater reclamation plant and evaluated the rejection of pharmaceuticals by nanofiltration (NF) and reverse osmosis (RO) membrane treatments. Pharmaceuticals such as Sulpiride, Bezafibrate, Levofloxacin and Ketoprofen were detected at concentrations more than 500 ng/L from the feed water of the NF/RO membrane treatments. The rejections of pharmaceuticals by the RO membrane treatment were more than 99 % except for three pharmaceuticals. The three pharmaceuticals such as Ethenzamide, Acetaminophen and Caffeine, whose molecular weights are less than 200, showed the rejections ranging from 95.8 to 97.9% by the RO membrane treatment. Meanwhile, a wide range of the rejections of pharmaceuticals was shown for the NF membrane treatment. As for the pharmaceuticals whose molecular weights are from 200 to 300, the rejections of negative charged anionic pharmaceuticals were higher than those of positive charged or non-charged pharmaceuticals by the NF membrane treatment.

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  • Takahiro MISAKI
    2021 Volume 77 Issue 4 Pages 122-131
    Published: 2021
    Released on J-STAGE: December 20, 2021
    JOURNAL FREE ACCESS

     I conducted field surveys in Kasukawa river once a month to examine the influence of heavy metals from industrial factories on benthic invertebrate communities. I selected one reference site and one metal polluted site that had a difference in heavy metal concentration and approximately equality in flow velocity, water depth and riverbed structure. I evaluated the toxic effects among copper, nickel and zinc additively. I compared the time series data of river environmental variables and benthic invertebrate indicators at the two sites using generalized linear mixed model. The difference in electric conductivity, transparency, cumulative criterion unit of these three metals, taxonomic species richness, the abundance, wet biomass, the abundance of Baetis thermicus, and the abundance of Chironomidae was statistically significant. I inferred that the effect of heavy metals on the structure of benthic invertebrate communities was that compositional changes of species caused by increasing heavy metal pollutions were simply a shift from communities composed of susceptible species to those composed only of tolerant species (Chironomidae) in Kasukawa river.

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  • Sadahiko ITOH, Sayaka HORI
    2021 Volume 77 Issue 4 Pages 132-143
    Published: 2021
    Released on J-STAGE: December 20, 2021
    JOURNAL FREE ACCESS

     A questionnaire survey on waterworks and water tariff was performed in four cities in Japan. As a result of a factor analysis and a covariance structure analysis, a psychological model with the end point of the citizens’ acceptance of water tariff increase was constructed. It was found that the citizens’ evaluation of the current water tariff has the strongest impact on the acceptance of water tariff increase. Consequently, the most important communication point for the acceptance is to improve the evaluation of water tariff by noticing that current water tariff is reasonable. In addition, the acceptance could be improved by the efforts that improve the evaluation of the communication conducted by water utility, the reliability on waterworks and the satisfaction on drinking water quality. On the other hand, the contribution of the knowledge on the conditions of waterworks for improving the acceptance is limited. Therefore, it should not be expected that the acceptance could be directly improved by improving the knowledge on the conditions of waterworks.

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