"Dissolved and Particulate Irons during the Stagnation Period in the Seasonally Anoxic Lake, Lake Fukami-ike : Dissolved Organic Iron"

P(論文)"Lake Fukami-ike is a small lake having a maximum depth of 8.0m, and is well protected from the wind. Lake water stratified from March to October and circulated from November to March. Anoxic condition prevailed below 4-5m depth from April to October. This study was undertaken to clarify in detail the distributions of iron chemical forms in Lake Fukami-ike. The concentration of dissolved iron seemed to be controlled by the balance among the supply of Allochtonous iron, the deposition or dissolution of particulate iron (P-Fe) in the hypolimnion and the FeS fixation at the bottom. The dissolved iron (D-Fe) in the hypolimnion water was specified by ultrafiltration. Percentages of dissolved iron in two molecular weight fractions in depth of 7.0m were 20-30% (M. W. 100,000), respectively. These results indicate that about 50-80% of total dissolved iron was present as the organic form, mainly having a molecular weight of 5,000-100,000, in the hypolimnion of Lake Fukami-ike."departmental bulletin pape