Dissolved organic carbon in a eutrophic lake; dynamics,biodegradability and origin |
| |
| Authors: | Takehiko Fukushima Je-chul Park Akio Imai Kazuo Matsushige |
| |
| Institution: | (1) National Institute for Environmental Studies, 16-2 Onogawa, 305 Tsukuba, Ibaraki, Japan;(2) Present address: Department of Civil and Environmental Engineering, Hiroshima University, Higashihiroshima, 739 Hiroshima, Japan;(3) Tokyo University of Fisheries, 4-5-7, Konan, 108 Minato-ku, Tokyo, Japan |
| |
| Abstract: | The seasonal and spatial changes in dissolved organic carbon (DOC) in Lake Kasumigaura, a shallow, eutrophic lake, were analyzed and the lability of DOC was tested by long-term incubations. There was a nearly 1 mgCl–1 downstream increase in refractory DOC in the lake; at the center it fluctuated little seasonally. The characteristic UV-absorbance: DOC ratios were determined for samples from the influent rivers (pedogenic: used interchangeably with  allochthonous ) and outdoor experimental ponds (autochthonous) during incubations. These ratios were then used to calculate the proportion of total measured lake water DOC in each of four components: pedogenic-refractory (PR), pedogenic-labile (PL), autochthonous-refractory (AR) and autochthonous-labile (AL). PR was uniform (around 1.5 mgCl–1) or diminished very slightly over time. AR increased from nearly zero at the station closest to an influent river to 1 mgCl–1 at the lake center. PL declined downstream from 0.3 mgCl–1 to zero. AL was virtually constant at 0.8 mgCl–1 except at the station closest to the influent river. The constancy of the UV-absorbance: DOC ratio during the biodegradation process was confirmed for Lake Kasumigaura; hence a two-component model (pedogenic-autochthonous) could be applied here without consideration of DOC lability. However, this assumption is not always met for other water bodies, and therefore it should be checked before applying a two-component model elsewhere. |
| |
| Keywords: | Dissolved organic carbon bio-degradation test pedogenic (allochthonous) authochthonous UV-absorbance |
| 本文献已被 SpringerLink 等数据库收录！ |
|
