| Title |
A Study on the Releasing Characteristics of Organic Matter and Heavy Metals and Changes of Dissolved Oxygen Concentration during Sediment Resuspension |
| Authors |
강선경 ( Seon Gyeong Kang ) ; 이한샘 ( Han Saem Lee ) ; 임병란 ( Byung Ran Lim ) ; 이동석 ( Dong Seok Rhee ) ; 신현상 ( Hyun Sang Shin ) |
| DOI |
https://doi.org/10.15681/KSWE.2021.37.1.1 |
| Keywords |
Dissolved organic matter; Dissolved oxygen; Heavy metal; Resuspension; Sediment oxygen demand |
| Abstract |
The depletion of dissolved oxygen (DO) in urban streams has a profound effect on the aquatic ecosystem; however, the change in DO by resuspension of sediments and the cause have not been sufficiently investigated. In this study, the physicochemical properties (particle size, and the content of organic and heavy metals) of the sediments of an urban stream (Anyang Stream) and the characteristics of water quality changes (DO, dissolved organic carbon (DOC), dissolved nitrogen (DN), sediment oxygen demand (SOD), and adenosine triphosphate (ATP)) by sediment resuspension were investigated. The sediment content of fine particles (< 0.2 mm) increased from 36.7% to 52.7% from the upstream to the downstream, and the contents of heavy metals and organic matter of the sediment were also higher towards the downstream. The depletion of DO by resuspension was observed in the sediment at the downstream sites (P8, P9), where the fine particle content was high, and biological SOD (BSOD) was more than 88% compared to the total SOD. The increase in BSOD coincided with the increase in ATP. It was also confirmed that the depletion of DO could increase the amount of heavy metals (such as Fe, Mn, and Pb) released from the sediment. Based on the above results, it can be concluded that resuspension of sediments induces rapid water quality changes and may cause accidents, such as fish mortality, during rainfall, and such a water quality effect can be more pronounced in sediments with a high content of fine particles and organic matter and high biological activity. |