SS3.04 Biogeochemistry of DOC/DON in a Watershed Context
Date: Wednesday, June 12, 2002
Location: Poster Session - VCC
 
ImaiA, National Institute for Environmental Studies, Tsukuba, Japan, aimai@nies.go.jp
Matsushige, K, , National Institute for Environmental Studies, Tsukuba, Japan, matusige@nies.go.jp
Choi, K, , National Institute for Environmental Studies, Tsukuba, Japan, choi.kwangsoon@nies.go.jp
Fukushima, T, , University of Tsukuba, Tsukuba, Japan, fukushima@arsia.geo.tsukuba.ac.jp
 
CHARACTERIZATION OF DISSOLVED ORGANIC MATTER IN SHALLOW EUTROPHIC LAKE KASUMIGAURA
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Dissolved organic matter (DOM) in water from eutrophic Lake Kasumigaura, its inflowing rivers, and several other DOM sources in the lake catchment area was fractionated using resin adsorbents into five classes: aquatic humic substances (AHS), hydrophobic neutrals (HoN), hydrophilic acids (HiA), bases (BaS), and hydrophilic neutrals (HiN). DOM-fraction distribution patterns were significantly different depending on the origin of the sample. AHS and HiA were found to be the dominant fractions in DOM in all samples studied. HiA prevailed over AHS in the lake water, whereas AHS were slightly more abundant than HiA in the river waters. AHS were in the great majority in forest streams and plowed-field percolates. HiA abounded in paddy-field outflow, domestic sewage, sewage-treatment-plant effluent and spent growth media of the dominant cyanobacterium Microcystis aeruginosa. A significant amount of HoN and HiN was found in domestic sewage and the growth media, respectively.