| Budget Amount *help |
¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000)
Fiscal Year 2017: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Outline of Final Research Achievements |
Considering from both the redox and the dissolution equilibria, it is expected that predominant Mn chemical species dissolved in oxic river waters is Mn (III) or Mn (IV) and the concentration of total dissolved Mn is less than μg dm-3 levels. However, there are many reports on the rivers in which the concentration of dissolved total Mn exceed that specified as environmental guidelines (200 μg dm-3). It is suggested that some mechanisms to increase the solubility of specific Mn species but further details are not clarified because to determine the concentrations of trace amounts of Mn in different oxidation state present in river water is quite difficult.
In this study we have developed a high sensitive and selective speciation method for trace Mn(II). By the practical application of this method on various river water samples, it could be clarified that predominant Mn species in rivers whose total Mn concentration exceeds the guideline value was Mn(II).
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