| 鄱阳湖沉积物可转化态氮分布特征及其对江湖关系变化的响应 |
| 摘要点击 2545 全文点击 1403 投稿时间：2014-07-01 修订日期：2014-08-22 |
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| 中文关键词 江湖关系变化 鄱阳湖 沉积物 可转化态氮 分布 |
| 英文关键词 change of river-lake relationship Poyang Lake sediment transferable nitrogen distribution |
| 作者 | 单位 | E-mail | | 沈洪艳 | 河北科技大学环境科学与工程学院, 石家庄 050018 | shy0405@sina.com | | 张绵绵 | 河北科技大学环境科学与工程学院, 石家庄 050018
中国环境科学研究院环境基准与风险评估国家重点实验室, 北京 100012
中国环境科学研究院湖泊创新基地, 国家环境保护湖泊污染控制重点实验室, 北京 100012 | | | 倪兆奎 | 中国环境科学研究院环境基准与风险评估国家重点实验室, 北京 100012
中国环境科学研究院湖泊创新基地, 国家环境保护湖泊污染控制重点实验室, 北京 100012 | | | 王圣瑞 | 中国环境科学研究院环境基准与风险评估国家重点实验室, 北京 100012
中国环境科学研究院湖泊创新基地, 国家环境保护湖泊污染控制重点实验室, 北京 100012 | wangsr@craes.org.cn |
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| 中文摘要 |
| 选取不同高程鄱阳湖表层沉积物, 通过研究其总可转化态氮与各形态可转化态氮含量及分布特征, 试图揭示江湖关系变化导致的水位变化对鄱阳湖沉积物氮潜在释放风险的影响. 结果表明: 1鄱阳湖表层沉积物总氮(TN)含量在389~3865 mg·kg-1之间,空间分布上呈"五河"入湖尾闾区>湖心区>北部湖区的趋势; 总可交换态氮含量在319.36~904.56mg·kg-1之间, 占TN的52%, 空间分布趋势与TN相同; 2鄱阳湖3个湖区沉积物各形态可转化态氮的含量大小排列次序均为: SOEF-N(强氧化剂可提取态氮)≈SAEF-N(强碱可提取态氮)>WAEF-N(弱酸可提取态氮)>IEF-N(离子交换态氮); 3江湖关系变化致使鄱阳湖枯水期沉积物出露时间提前并且延长, 进而导致不同高程沉积物可转化态氮(TTN)含量差异明显, 3个湖区沉积物可转化态氮含量均表现为枯水期>丰水期, 高程越高, 由于其沉积物出露时间较长, 可转化态氮含量较高, 即可转化态氮含量12 m~13 m高程沉积物>11 m~12 m高程沉积物>10 m~11 m高程沉积物; 4随着高程的增加, 沉积物各形态可转化态氮含量都呈现增加的趋势, 其中SAEF-N和WAEF-N含量及其占总可转化态氮的比例变化幅度较小, 而IEF-N和SOEF-N含量以及其占总可转化态氮比例的增幅均较为显著. 如果江湖关系进一步变化, 枯水期水位继续下降, 势必会引起沉积物出露面积增大及出露时间延长, 从而导致沉积物TN、可转化态氮以及释放风险较高的氮形态IEF-N和SOEF-N含量的增大, 来年丰水期可能会增加鄱阳湖沉积物氮释放风险. |
| 英文摘要 |
| Amounts and distributions of total transferable nitrogen and different transferable nitrogen forms were studied in the sediments of Poyang Lake with different regimen, in order to reveal the influence of the water level change caused by the River-Lake relationship change on the potential release risks of nitrogen. The results showed that: 1the contents of the total nitrogen(TN) were between 389 and 3865 mg·kg-1,and the spatial distribution showed an overall downward trend in the "Five River",the "Hu Xin" and the northern regions; the contents of the transferable total nitrogen(TTN) were between 319.36 and 904.56 mg·kg-1 and contributed 52% to the TN,and its spatial distribution trend was the same as that of TN.2The content of transferable nitrogen followed the order of SOEF-N≈SAEF-N>WAEF-N>IEF-N. 3The dry period advanced and the low water level continued to decline as a result of the change in River-Lake relationship of the Poyang Lake, leading to the prolonged outcropped time of sediments and the increased area, causing the different contents of transferable nitrogen in the sediments at different elevations.The transferable nitrogen content of the sediments in the whole lake during the wet period was lower than that during the dry period. The content of transferable nitrogen followed the order of 12-13 m elevation sediment>11-12 m elevation deposition material>10-11 m elevation sediments. The higher the elevation, the longer the sediments were exposed, and the higher the transferable nitrogen content. 4With the increase of elevation, all forms of N contents increased. The increase of IEF-N and SOEF-N contents as well as their percentages in total transferable nitrogen was relatively small, while the increase of WAEF-N and SAEF-N contents as well as their percentages in total transferable nitrogen was relatively large. If the river-lake relationship changes further, the elevation in the dry period will further decrease, which will lead to the enlarged area and prolonged exposure of sediments, resulting in increase of TN, transferable nitrogen, IEF-N and SOEF-N contents in the sediments. At the coming wet period of next year, the nitrogen release risk from sediments of Poyang Lake might increase. |
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