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Volume 36 (2013)
- Issue 6 Pages 157-
- Issue 5 Pages 137-
- Issue 4 Pages 107-
- Issue 3 Pages 67-
- Issue 2 Pages 29-
- Issue 1 Pages 1-
Predecessor
Volume 36, Issue 5
Displaying 1-3 of 3 articles from this issue
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Note
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Sumie SASAKI, Shuji NARITA, Yukie KIKUCHI, Kiyoshi FUDAArticle type: Note
2013 Volume 36 Issue 5 Pages 137-141
Published: 2013
Released on J-STAGE: September 10, 2013
JOURNAL FREE ACCESSA significant amount of reddish brown sediment was found at the sluice gate of the neutralization treatment plant for Tamagawa hot spring acidic water. The reduction in the concentrations of As and Cr in the spring water was studied in relation to sediment formation. XRD analysis and FT-IR spectrometry revealed that the sediment mainly consisted of a poorly crystallized iron hydroxide phase, which is similar to the mineral schwertmannite. The concentrations of Fe, As and Cr in fresh spring water were 150, 2.8, and 0.093 mg·L-1, respectively, these concentrations respectively decreased to 55, 0.75, and 0.025 mg·L-1 after the neutralization treatment. On the other hand, the concentrations of these elements in the sediment were respectively determined to be 39, 1.7, and 0.020 wt.%. The above these results strongly suggested that As and Cr accumulate in the sediment during the neutralization treatment process.View full abstractDownload PDF (1949K)
Note
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Shingo MASUKI, Kuniaki TOSHIMA, Hiroshi BESSYO, Yoichi WADA, Shogo SUG ...Article type: Note
2013 Volume 36 Issue 5 Pages 143-148
Published: 2013
Released on J-STAGE: September 10, 2013
JOURNAL FREE ACCESSThis paper is intended as a report on the blue tide situation in Jyushiken River on the west side of Lake Shinji. In addition, we consider the factors leading to blue tide formation using a cross-sectional figure of water quality changes. The result shows that wind-driven current due to a strong west wind is one of the possible causes of blue tide. The other possible cause is not necessarily the high-salinity (8∼10‰) bottom layer of Lake Shinji, but rather, the relatively low-salinity water (5∼7‰) near the surface. The cause of anoxia of the relatively low-salinity water is long-term stagnation.View full abstractDownload PDF (1587K)
Technical Report
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Tomotaka YANAGITA, Yaozong JIANG, Mirai NAKAMURAArticle type: Technical Report
2013 Volume 36 Issue 5 Pages 149-155
Published: 2013
Released on J-STAGE: September 10, 2013
JOURNAL FREE ACCESSThe arsenic adsorption properties of a new iron hydroxide synthesized from ferrous sulfate, sodium hypochlorite, and sodium hydroxide were examined. The main constituents of the new compound were iron, sulfur, chlorine, and sodium. It was confirmed by X-ray, TG/DTA, and SEM analyses that the new compound is amorphous. Arsenic adsorption obeyed the Langmuir isotherm, and a high adsorption ability was observed at low to high arsenic concentrations. At an arsenic concentration of 20 mg·L-1 and an adsorbent amount of 10 g·L-1, As(III) and As(V) were adsorbed rapidly so that the arsenic concentration decreased to below the detection limit within 1 min. Under the same conditions as described above, As(III) and As(V) were almost completely removed at pH of 3.0 to 9.0 within 1 h. Coexisting ions, SO42-, Cl-, NO3-, and HCO3-, did not affect the arsenic adsorption by the new iron hydroxide. The arsenic adsorption ability was also satisfactory in the column continuous experiment.View full abstractDownload PDF (1433K)
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