Journal of Japan Society on Water Environment
Online ISSN : 1881-3690
Print ISSN : 0916-8958
ISSN-L : 0916-8958
Volume 45, Issue 1
Displaying 1-4 of 4 articles from this issue
Research Paper
  • Shiori NITTA, Riku IZUMIDA, Runda DU, Yisong HU, Yu You LI
    Article type: Research Paper
    2022 Volume 45 Issue 1 Pages 1-9
    Published: 2022
    Released on J-STAGE: January 10, 2022
    JOURNAL FREE ACCESS

    To apply the one-stage partial nitritation-anammox (PNA) process to municipal mainstream wastewater, an experiment on continuous nitrogen removal using hydroxyapatite crystallization and partial nitritation-anammox (HAP-PNA) granule was conducted at 25 ℃ using real sewage pretreated with anaerobic membrane bioreactors (AnMBR) . In the sewage adaptation period, the ammonium concentration of the sewage was firstly adjusted to 150 mg-N L-1 and then gradually decreased to 100 and then to 50 mg-N L-1. Finally, the real sewage treatment with the ammonium concentration of 33 mg-N L-1 for long-term operation at HRT of 2 h. Results of the continuous feeding tests for the real sewage treatment, showed that a nitrogen removal efficiency of 87% was obtained at HRT of 2 h, and the rates of ammonium oxidation and nitrogen removal by anammox bacteria were 0.20 and 0.34 kg-N (m3 d) -1, respectively. From the results of microbial analysis, the top two dominant species were the anammox bacteria and AOB, with relative abundances of 30.2% (Candidatus Kuenenia stuttgartiensis) and 13.6% (Nitrosomonas sp.) , respectively. Therefore, it was shown that AOB and anammox bacteria involved in the PNA process could be maintained during the real sewage treatment. This is the first demonstration of the successful operation and stable high performance of the PNA process with HAP-PNA granule for treating mainstream sewage.

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  • Satoko MISHIMA, Kenji OZAWA, Shunichi NAKAYAMA, Hiromi KIKUCHI, Ayumi ...
    Article type: Research Paper
    2022 Volume 45 Issue 1 Pages 11-19
    Published: 2022
    Released on J-STAGE: January 10, 2022
    JOURNAL FREE ACCESS
    Supplementary material

    Research on plastic debris in the ocean and rivers is being vigorously conducted, but there is little research on the dynamics of plastic from the basin, which is one of the sources of plastic waste, to rivers and coasts. In this study, we conducted a field survey of basins (roads) , rivers, and coasts in the Hikichi River basin, Kanagawa Prefecture, with the aim of clarifying the dynamics of plastic pieces in the basin, river, and coast. From the results of the sample particle recovery test, the target size of the plastic piece in this study was set to be > 1 mm. The results indicated that the numerical and mass concentration of plastic pieces in the road dust between districts considered were significantly higher in the commercial and residential areas, respectively, mainly because of the difference in plastic piece size distribution. A comparison of plastic materials on roads, rivers, and coasts showed that polyethylene (PE) , polypropylene (PP) , and polystyrene (PS) , which have low specific gravity, were predominant in the river and materials washed up on the coast, but not significant in the road dust.

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Survey Paper
  • Keiko WADA, Hiroshi TSUNO, Naoko TAKEI
    Article type: Survey Paper
    2022 Volume 45 Issue 1 Pages 21-27
    Published: 2022
    Released on J-STAGE: January 10, 2022
    JOURNAL FREE ACCESS

    From field surveys of roof runoff conducted in general residential houses in the Lake Biwa basin, the pollution loads of buildings in an urban area were evaluated. The samples were collected from the total roof drainage during a rainfall event, and the water pollutants investigated were total organic carbon (TOC) , total nitrogen (TN) , and total phosphorus (TP) . As a result, it was estimated that 67.7% of the total precipitation flowed out as roof wastewater, and it was clarified that the proportion of dissolved components was high in all cases. The calculated loads of TOC, TN, and TP from buildings were 60.4, 18.1, and 0.64 g ha-1 day-1, respectively. By applying these loads and roadway loads in the Lake Biwa basin, the basic unit pollution loads of TOC, TN, and TP in the urban area of the Lake Biwa basin were estimated to be 140, 24.2, and 1.1 g ha-1 day-1, respectively.

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  • Katsushige URANISHI, Yosuke URANISHI, Mayumi TSUJIMOTO, Jirou SHIROYAM ...
    Article type: Survey Paper
    2022 Volume 45 Issue 1 Pages 29-39
    Published: 2022
    Released on J-STAGE: January 10, 2022
    JOURNAL FREE ACCESS

    An environmental standard on the number of coliforms in public rivers was set in 1970 to indicate fecal contamination, but its low indexability has been a problem. In this study, we investigated the usefulness of the hydrophobic gridded membrane filter (HGMF) method using CHROMagar-ECC nutrient agar and the Colilert method for the simultaneous enumeration of coliform bacteria and coliforms, in addition to the prescribed method based on notification No.94 in 2011 of the Ministry of the Environment that can only detect coliform bacteria. From the results of the survey in the Yamato River system, we found that the three methods showed a certain consistency of results, and that the HGMF and Colilert methods were capable of identifying the sites with high contamination levels which could not be determined from coliform counts alone. We also verified how the accuracy of a new environmental standard would change when the current environmental standard is revised from the coliform group count to the Escherichia coli count, and we found that many points on effectiveness that had not been realized with the current standard are expected to be realized after the standard after the revision.

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