| 三峡水库香溪河沉积物氮含量和氨氮释放特征 |
| Total Nitrogen Content and Ammonia Nitrogen Release from Surface Sediments of Xiangxi River, Three Gorges Reservoir Region |
| 投稿时间：2017-11-03 修订日期：2019-03-31 |
| DOI：10.15928/j.1674-3075.2019.03.001 |
| 中文关键词:香溪河 沉积物 氮形态 氨氮释放 |
| 英文关键词:Xiangxi River sediment total nitrogen ammonia nitrogen release |
| 基金项目:国家自然科学基金重大计划项目(91647207);国家自然科学基金项目(51509086)；国家国际科技合作项目(2014DFE70070)；十二五国家水专项子题：库区支流水华控制的水库群联合调度技术研究及示范(2014ZX07104-005-02)；国家重点研究计划“面向江河湖库生态安全的水库群调度技术”(2016YFC0402204) |
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| 中文摘要: |
| 通过分析三峡水库香溪河库湾表层沉积物的理化性质和氮素分布特征，并结合室内动力学实验，对香溪河库湾沉积物氮素的组成差异和氨氮释放动力学模型进行了探讨，分析了沉积物氨氮释放潜能。结果表明，香溪河表层沉积物中总氮含量为195.00~1813.93 mg/kg，氨氮含量为34.98~296.55 mg/kg，硝氮含量为13.19~224.08 mg/kg 。采用一级动力学模型模拟了氨氮释放动力学，氨氮的最大释放量为67.06~74.43 mg/kg，是长江中下游湖泊平均值的1.5倍，存在一定的释放风险；表层沉积物在起始0～5 min内快速释放，达到最大释放量的97.90%~98.41%，150 min后基本达到释放平衡。香溪河氨氮的平均释放量在水土质量比为5000时达到最大，随后趋于平衡。相关性分析发现，最大释放量与释放潜能均与沉积物中有机质含量和粒度分布相关性不明显，这可能与香溪河的水环境特点有关。 |
| 英文摘要: |
| Endogenous pollution of sediments is a primary cause of water eutrophication and receiving national and international attention. Nitrogen from sediments is released primarily in the form of NH4+-N and continued research on NH4+-N release is necessary. In this study, we determined the distribution of different forms of nitrogen in the sediment of Xiangxi Bay and studied the kinetics of NH4+-N release from sediment, based on sediment physical and chemical parameters. Results provide a theoretical basis for eutrophication control in the backwater area of Xiangxi River. In July 2017, sediment samples were collected at three sites: Site 1, near the mouth of the river; Site 2, near the town of Xiakou; and Site 3, Xiangxi River upstream of Xiakou. The physical and chemical parameters of the sediments were determined, including total nitrogen (TN), ammonia nitrogen (NH4+-N), nitrate nitrogen（NO3--N, total phosphorous (TP), pH, dissolved oxygen (DO) and temperature (T). Then the kinetics of NH4+-N release from sediments were investigated in the laboratory. Results show that the TN content in the sediments varied from 683.71-843.19 mg/kg and followed the order, Site 2>Site 1>Site 3. The content of NH4+-N in the sediments ranged from 122.77 to 237.85 mg/kg and followed the order, Site 3>Site 2>Site 1. The content of NO3--N in the sediments ranged from 35.78 to 237.85 mg/kg and followed the order of Site 1>Site 3>Site 2. The release of NH4+-N from surface sediment was well simulated by first-order kinetics. The largest release rate of NH4+-N was 67.06-74.43 mg/kg, 1.5 times the average reported for the middle and lower reaches of the Yangtze River, indicating high risk. The release of NH4+-N occurred primarily in the first five minutes, accounting for 97.9%-98.4% of the total release, and reached equilibrium after ~150 minutes. The NH4+-N release peaked at a water to soil ratio of ~5000:1. Correlation analysis shows that NH4+-N release is not significantly correlated with sediment organic matter content or particle size distribution. This may be related to the particular characteristics of the Xiangxi River water environment and will be investigated in future research. |
| 苏青青,宋林旭,刘德富,纪道斌,李欣,刘心愿,方海涛,张庆文.2019.三峡水库香溪河沉积物氮含量和氨氮释放特征[J].水生态学杂志,40(3):1-7. |
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