| Title |
Characteristics of Dissolved Organic Matter(DOM) Based on Molecular Weight Fractions and Fluorescence Properties in the Downstream Nakdong River |
| Authors |
지화성 ( Hwaseong Ji ) ; 김미희 ( Mihee Kim ) ; 이유정 ( Youjung Lee ) ; 손희종 ( Heejong Son ) |
| DOI |
https://doi.org/10.15681/KSWE.2020.36.3.194 |
| Keywords |
FDOM; sub; H; sub; FDOM; sub; P; sub; LC-OCD; SUVA; sub; 254nm; sub |
| Abstract |
The characteristics and behavior of dissolved organic matter (DOM) were determined by analyzing the molecular weight fractions and fluorescence properties of water samples in the downstream Nakdong River. Biogeochemical water quality parameters and fluorescent dissolved organic matter (FDOM) were analyzed at five sampling points in the downstream area of the Nakdong River January-August 2019. The molecular weight fractions of the DOM were separated by the Liquid Chromatography-Organic Carbon Detection (LC-OCD). The DOM predominantly comprised humic substances, followed by the building blocks, low molecular weight neutrals and biopolymers. The hydrophobic (aromatic) and hydrophilic properties were shown as coexisting, as most of the SUVA254nm values were under four. The FDOM was characterized as humic-like (FDOMH) with allochthonous origin and protein-like (FDOMP) with autochthonous origin; the FDOMH with autochthonous origin was also identified. The FDOMH relies on the aromaticity of the allochthonous organic matter and increases during summer. The FDOMH and FDOMP, which depend on the biodegradable dissolved organic matter from phytoplankton, were highly fluorescent in winter. The allochthonous organic matter was the dominant factor contributing to the behavior of the DOM, externally introduced to the river by rainfall. The FDOM only minimally contributed to the behavior of the DOM. It can be explained as the seasonal characteristics of the DOM, varied by the source of the organic matter. |