Transformation and fate of nitrate near the sediment-water interface of Copano Bay
Transformation and fate of nitrate near the sediment-water interface of Copano Bay
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DOI：
10.1016/j.csr.2012.01.004
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发表时间：
2012-03-01
影响因子：
2.3
通讯作者：
Gardner, Wayne S.
中科院分区：
文献类型：
--
作者：
Hou, Lijun;Liu, Min;Gardner, Wayne S.
本研究通过连续流试验和泥浆试验，结合(NO3-)- n -15添加技术，研究了干旱时期Copano湾沉积物-水界面硝酸盐的潜在转化过程和命运。基于(NO3-)-N-15的反硝化速率、厌氧氨氧化速率（ANAMMOX）和潜在异化硝态氮还原成铵速率（DNRA）分别在27.7 ~ 40.1、0.26 ~ 1.6和1.4 ~ 3.8 μ mol N-15 m(-2) h（-1）之间。与进入沉积物的总（15）NO(3)（-）通量相比，异化过程对(NO3-)- n -15的损失贡献了29-49%。根据(NO3-)- n -15的质量平衡，估计微生物同化消耗了添加的(NO3-)- n -15的50-70%左右，表明在这个限氮系统中，大部分硝酸盐被微生物吸收。此外，硝酸盐转化速率与沉积物特征显著相关，反映了岩心沉积物中硝酸盐转化的深度相关行为与有机质、铁（Fe）和硫(S)循环密切相关。(C) 2012 Elsevier Ltd.版权所有。
This study investigated potential transformation processes and fates of nitrate at the sediment-water interface of Copano Bay during a period of drought by conducting continuous-flow and slurry experiments combined with a (NO3-)-N-15 addition technique. Rates of (NO3-)-N-15-based denitrification, anaerobic ammonium oxidation (ANAMMOX) and potential dissimilatory nitrate reduction to ammonium (DNRA) were in the range of 27.7-40.1, 0.26-1.6 and 1.4-3.8 mu mol N-15 m(-2) h(-1), respectively. Compared with the total (15)NO(3)(-)fluxes into sediments, dissimilatory processes contributed 29-49% to loss of the spiked (NO3-)-N-15. Based on the mass balance of (NO3-)-N-15, microbial assimilation was estimated to consume about 50-70% of the added (NO3-)-N-15, indicating that most of nitrate was incorporated by microorganisms in this N-limiting system. In addition, significant correlations of nitrate transformation rates with sediment characteristics reflect that the depth related behaviors of nitrate transformations in core sediments were coupled strongly to organic matter, iron (Fe) and sulfur (S) cycles. (C) 2012 Elsevier Ltd. All rights reserved.