| 河流库区沉积物-水界面营养盐及气态氮的释放过程和通量 |
| 摘要点击 3140 全文点击 1753 投稿时间：2014-01-27 修订日期：2014-03-24 |
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| 中文关键词 水库 沉积物 氮磷 N2 N2O 九龙江 |
| 英文关键词 reservoir sediment nitrogen and phosphorus N2 N2O Jiulong River |
| 作者 | 单位 | E-mail | | 陈朱虹 | 厦门大学环境与生态学院, 福建省海陆界面生态环境重点实验室, 厦门 361102 | 597721118@qq.com | | 陈能汪 | 厦门大学环境与生态学院, 福建省海陆界面生态环境重点实验室, 厦门 361102 | nwchen@xmu.edu.cn | | 吴殷琪 | 厦门大学环境与生态学院, 福建省海陆界面生态环境重点实验室, 厦门 361102 | | | 莫琼利 | 厦门大学环境与生态学院, 福建省海陆界面生态环境重点实验室, 厦门 361102 | | | 周兴鹏 | 厦门大学环境与生态学院, 福建省海陆界面生态环境重点实验室, 厦门 361102 | | | 鲁婷 | 厦门大学环境与生态学院, 福建省海陆界面生态环境重点实验室, 厦门 361102 | | | 田蕴 | 厦门大学生命科学学院, 厦门 361102 | |
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| 中文摘要 |
| 以九龙江北溪西陂电站库区为例，于2013年不同季节开展原状泥柱静态培养、气态氮水柱剖面观测和通量模拟实验，结合水和沉积物理化参数和微生物参数，研究河流库区沉积物-水界面营养盐及气态氮的释放过程和通量. 结果表明，库区沉积物NH4+和PO43-总体表现为释放行为[平均NH4+通量（480±675）mg ·（m2 ·d）-1，平均PO43-通量（4.56±0.54）mg ·（m2 ·d）-1]，而NO3-和NO2-表现为吸附行为. 洪水季节带来大量的有机质沉积在库区，造成枯水期沉积物无机氮磷向上覆水体释放. 湖泊区气态氮释放以N2为主（>98%），沉积物-水界面N2释放通量平均为（15.8±12.5）mg ·（m2 ·d）-1. 水柱N2净增量有明显的空间差异和垂向分布规律，受沉积物-水界面生地化过程（反硝化和厌氧氨氧化作用）和流动水团的综合影响. 下游站位存在较强的硝化作用，N2O相对富集，主要受水中氨氮占无机氮的比例控制. |
| 英文摘要 |
| The key processes and fluxes of nutrients (N and P) and gaseous N (N2 and N2O) across the sediment-water interface in a river reservoir (Xipi) of the Jiulong River watershed in southeast China were studied. Intact core sediment incubation of nutrients exchange, in-situ observation and lab incubation of excess dissolved N2 and N2O (products of nitrification, denitrification and Anammox), and determination of physiochemical and microbe parameters were carried out in 2013 for three representative sites along the lacustrine zone of the reservoir. Results showed that ammonium and phosphate were generally released from sediment to overlying water [with averaged fluxes of N (479.8±675.4) mg ·(m2 ·d)-1 and P (4.56±0.54) mg ·(m2 ·d)-1], while nitrate and nitrite diffused into the sediment. Flood events in the wet season could introduce a large amount of particulate organic matter that would be trapped by the dam reservoir, resulting in the high release fluxes of ammonium and phosphate observed in the following low-flow season. No clear spatial variation of sediment nutrient release was found in the lacustrine zone of the reservoir. Gaseous N release was dominated by excess dissolved N2(98% of total), and the N2 flux from sediment was (15.8±12.5) mg ·(m2 ·d)-1. There was a longitudinal and vertical variation of excess dissolved N2, reflecting the combined results of denitrification and Anammox occurring in anoxic sediment and fluvial transport. Nitrification mainly occurred in the lower lacustrine zone, and the enrichment of N2O was likely regulated by the ratio of ammonium to DIN in water. |
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