|
|||||
|
|
Decomposition of algal lipids in clay-enriched marine sediment under oxic and anoxic conditions |
|
| Authors: | Dongwei Lü Qian Song Xuchen Wang |
| Institution: | 1. Marine Biogeochemistry Laboratory, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China 2. Graduate School of Chinese Academy of Sciences, Beijing, 100039, China 3. College of food and wine, China Agriculture University (Yantai), Yantai, 264670, China 4. Department of Environmental, Earth and Ocean Sciences, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA, 02125, USA |
| Abstract: | A series of laboratory incubation experiments were conducted to examine the decomposition of algal organic matter in clay-enriched marine sediment under oxic and anoxic conditions. During the 245-day incubation period, changes in the concentrations of TOC, major algal fatty acid components (14:0, 16:0, 16:1, 18:1 and 20:5), and n-alkanes (C16–C23) were quantified in the samples. Our results indicate that the organic matters were degraded more rapidly in oxic than anoxic conditions. Adsorption of fatty acids onto clay minerals was a rapid and reversible process. Using a simple G model, we calculated the decomposition rate constants for TOC, n-alkanes and fatty acids which ranged from 0.017–0.024 d−1, 0.049–0.103 d−1 and 0.011 to 0.069 d−1, respectively. Algal organic matter degraded in two stages characterized by a fast and a slow degradation processes. The addition of clay minerals montmorillonite and kaolinite to the sediments showed significant influence affecting the decomposition processes of algal TOC and fatty acids by adsorption and incorporation of the compounds with clay particles. Adsorption/association of fatty acids by clay minerals was rapid but appeared to be a slow reversible process. In addition to the sediment redox and clay influence, the structure of the compounds also played important roles in affecting their degradation dynamic in sediments. |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ | |