Benthic flux of dissolved organic matter from lake sediment at different redox conditions and the possible effects of biogeochemical processes.
Benthic flux of dissolved organic matter from lake sediment at different redox conditions and the possible effects of biogeochemical processes.
复制标题
DOI：
10.1016/j.watres.2014.05.009
复制
发表时间：
2014-09
期刊：
影响因子：
12.8
通讯作者：
Liyang Yang;J. Choi;J. Hur
中科院分区：
文献类型：
--
作者：
Liyang Yang;J. Choi;J. Hur
通过室内底栖箱实验，研究了人工湖沉积物中溶解有机碳（DOC）、发色和荧光溶解有机物（CDOM和FDOM）的底栖通量。在缺氧和好氧条件下，底栖DOC通量的保守估计值分别为71 ± 142和51 ± 101 mg m− 2 day − 1。利用荧光激发发射矩阵和平行因子分析（EEM-PARAFAC）从样品中鉴定出两种腐殖酸类（C1和C2）、一种腐殖酸类（C3）和一种微生物腐殖酸类（C4）组分。在培养期间，C3被去除，而C4积累在上覆水中，氧化还原条件之间的趋势没有显着差异。腐殖化指数（HIX）随时间的延长而增加。结合C3、C4和HIX的分析结果，微生物转化可能是影响DOM通量的重要过程。相反，CDOM，C1，和C2在上覆水中的整体积累只发生在缺氧条件下，这可能是由它们的增强的光降解和吸附氧化还原敏感的矿物在好氧条件下的解释。我们的研究表明，在湖泊沉积物中DOM的底栖通量显着，也可能参与的过程中的地球化学转化，提供洞察内陆沃茨的碳循环。
The benthic fluxes of dissolved organic carbon (DOC), chromophoric and fluorescent dissolved organic matter (CDOM and FDOM) were studied for the sediment from an artificial lake, based on laboratory benthic chamber experiments. Conservative estimates for the benthic flux of DOC were 71 ± 142 and 51 ± 101 mg m−2day−1at hypoxic and oxic conditions, respectively. Two humic-like (C1 and C2), one tryptophan-like (C3), and one microbial humic-like (C4) components were identified from the samples using fluorescence excitation emission matrices and parallel factor analysis (EEM-PARAFAC). During the incubation period, C3 was removed while C4 was accumulated in the overlying water with no significant difference in the trends between the redox conditions. The humification index (HIX) increased with time. The combined results for C3, C4 and HIX suggested that microbial transformation may be an important process affecting the flux behaviors of DOM. In contrast, the overall accumulations of CDOM, C1, and C2 in the overlying water occurred only for the hypoxic condition, which was possibly explained by their enhanced photo-degradation and sorption to redox-sensitive minerals under the oxic condition. Our study demonstrated significant benthic flux of DOM in lake sediment and also the possible involvement of biogeochemical transformation in the processes, providing insight into carbon cycling in inland waters.