Preferential regeneration of P relative to C in a freshwater lake
Preferential regeneration of P relative to C in a freshwater lake
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淡水湖中 P 相对于 C 的优先再生
DOI：
10.1016/j.chemosphere.2019.01.088
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发表时间：
2019-05-01
期刊：
影响因子：
8.8
通讯作者：
Lu, Yaoting
中科院分区：
文献类型：
--
作者：
Chen, Jingan;Zeng, Yan;Lu, Yaoting
颗粒有机物（POM）是碳（C）、氮（N）、磷（P）在地球化学循环中的主要载体。以往的研究发现，海洋环境中POM降解过程中，C、N、P的再生过程存在明显差异。然而，到目前为止，湖泊系统的研究还很少。本文对红枫湖表层沉积物和悬浮颗粒物（SPM）中C、N和P的含量进行了系统研究，初步探讨了湖泊系统中C、P的再生行为。结果表明，悬浮颗粒物中总有机碳（TOC）与总磷（TP）的比值（TOC/P）明显低于表层沉积物，首次证明了湖泊系统中磷相对于碳的优先再生性。根据悬浮颗粒物与沉积物TOC/P比值的差异，估算出红枫湖沉积物和悬浮颗粒物每年释放的P约为25.1t，远高于前人对沉积物释放P通量的估算。这表明，在颗粒物在水体中的传输过程中，可能会有显着比例的P再生，提供了新的见解磷再生湖泊系统。磷的优先再生可能导致底层水缺氧、磷再生增强和次深湖水华之间的正反馈循环。(C)2019爱思唯尔有限公司版权所有。
Particulate organic matter (POM) is the main carrier of carbon (C), nitrogen (N), and phosphorus (P) in the biogeochemical cycle. Previous investigations have found that the regeneration of C, N, and P is obviously different during the degradation of POM in marine environments. However, little attention has been paid to lake system thus far. In an initial attempt to characterize the regeneration behaviors of C and P in lake system, contents of C, N, and Pin suspended particulate matter (SPM) and surface sediments of Hongfeng Lake were systematically investigated in this study. The results showed that the total organic carbon (TOC) to total phosphorus (TP) ratios (TOC/P) were obviously lower in SPM than in surface sediments, which demonstrated the preferential regeneration of P relative to C in lake system for the first time. Possible mechanisms for such include reductive dissolution of Fe oxyhydroxide and poly-P remineralization under hypoxic/anoxic conditions.Based on the difference in the TOC/P ratios between SPM and surface sediments, about 25.1 t P was estimated to be released annually from settling seston and sediments in Hongfeng Lake, which is much higher than the previous results on the P release flux from sediment. This indicates that a significant percentage of P may be regenerated during particulate matter transport in the water column, providing new insight into the P regeneration in lake system. The preferential regeneration of P may result in a positive feedback loop among bottom water anoxia, enhanced P regeneration, and algal bloom in sub-deep lakes. (C) 2019 Elsevier Ltd. All rights reserved.