Dynamics of phosphorus-iron-sulfur at the sediment-water interface influenced by algae blooms decomposition
Dynamics of phosphorus-iron-sulfur at the sediment-water interface influenced by algae blooms decomposition
复制标题
藻华分解对沉积物-水界面磷-铁-硫动态的影响
DOI：
10.1016/j.jhazmat.2015.07.009
复制
发表时间：
2015-12-30
影响因子：
13.6
通讯作者：
Xu, Di
中科院分区：
文献类型：
--
作者：
Han, Chao;Ding, Shiming;Xu, Di
这项研究解决了藻类大量繁殖对湖泊沉积物-水界面 (SWI) 磷 (P)、铁 (Fe) 和硫 (S) 动态的先前未知的影响。基于薄膜技术 (DGT) 中两种最近开发的扩散梯度，现场进行了介观实验来研究这些效应。添加藻类后的水体中可溶性 P、Fe(II) 和 S(-II) 表现出相似的变化趋势。峰值浓度出现在 16 天实验的第 7 天。最低的 Eh 出现在实验的中间点，表明藻类严重退化。 DGT 不稳定的 S 的最大增加出现在 SW 附近的第 8 天！，而 DGT 不稳定的 P 和 Fe 几乎到实验结束时都表现出持续增加。在沉积物中观察到不稳定磷在不稳定铁和不稳定硫之间的转换呈显着正相关，这表明藻类分解下磷的原始铁耦合动力学发生了显着变化。表观通量是根据 DGT 剖面计算的，其中降解藻类同时释放 P 和 S，导致从沉积物到上覆水体的双向扩散通量。相比之下，由于深度增加和明显的正通量，沉积物成为不稳定铁的主要来源。 (C) 2015 Elsevier B.V. 保留所有权利。
This study addresses the previously unknown effects of algae blooms on the dynamics of phosphorus (P), iron (Fe) and sulfur (S) across a lacustrine sediment-water interface (SWI). A mesocosm experiment was conducted in-situ to investigate these effects based on two recently-developed diffusive gradients in thin-films techniques (DGT). Soluble P, Fe(II), and S(-II) exhibited similar changing trends in a water column subject to the algae addition. Peak concentrations appeared on day 7 of the 16-day experiment. The lowest Eh occurred at the experiment's midway point indicating a strong algae degradation. A maximum increase in DGT-labile S appeared on day 8 near the SW!, while the DGT-labile P and Fe exhibited persistent increases almost to the end of experiment. Significantly positive correlations of labile P were observed switching from between labile Fe and labile S in sediments, suggesting a significant change in original Fe-coupled dynamics of P under algae decomposition. Apparent fluxes were calculated based on DGT profiles where a simultaneous release of P and S occurred from degraded algae, resulting in bidirectional diffusion fluxes from sediment to overlying water. In contrast, sediment acted as a major source of labile Fe due to added depth and apparently positive fluxes. (C) 2015 Elsevier B.V. All rights reserved.