| 海洋表层沉积物中的无机氮在扰动情况下的行为特征 |
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| 作者姓名： | 王丕波 宋金明 郭占勇 李鹏程 |
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| 作者单位： | 1. 中国科学院海洋研究所, 青岛 266071;
2. 中国科学院研究生院, 北京 100049 |
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| 基金项目： | 中国科学院知识创新工程重大项目(KZCX1-SW-01-08)资助 |
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| 摘 要： | 模拟了海洋表层沉积物再悬浮对海水中NH4+-N、NO3--N浓度的贡献.通过实验,观察到海水中NH4+-N的浓度与沉积物和海水的混合比例成负相关.在不同振荡速率的试验中,60r/min振荡速率下的NH4+-N浓度逐渐降低到三种速率中的最低,120r/min振荡速率下的NH4+-N浓度升至最高.所选海区的沉积物在再悬浮过程中细粒径沉积物对上层水体NH4+-N的贡献最大,其次是中粒径沉积物、粗粒径沉积物.海水中NO3--N的浓度与混合比例和振荡速率均成负相关.粗、细粒径沉积物在试验过程中对水体的贡献具有很强的一致性,中粒径沉积物对水体的贡献要大于粗、细粒径沉积物的贡献.再悬浮过程中沉积物对海水中NO3--N、NH4+-N的贡献主要来源于KCl浸取态氮和HAc-NaAc浸取态氮。
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| 关 键 词： | 沉积物 氨态氮 硝酸态氮 再悬浮 |
| 收稿时间： | 2004-11-15 |
| 修稿时间： | 2005-03-03 |
Simulated Effects of Resuspension of Sea Surface Sediments on Concentration of Inorganic Nitrogen |
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| Authors: | WANG Pi-Bo SONG Jin-Ming GUO Zhan-Yong LI Peng-Cheng |
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| Institution: | 1. Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;
2. Graduate School, Chinese Academy of Sciences, Beijing 100049, China |
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| Abstract: | This experiment simulated the sediment resuspension caused by shaking through variable speed reciprocal shaker (HY-4) under the room temperature,and studied the change of nitrogen concentration.In the experiment,the concentration of NH4+-N in water was found to have a negative relation with the increasing ratios between the mass of sediment and the volume of seawater.About 6h later,the concentration in water with shaking rate of 60rPmin decreased to the lowest of the three rates.The concentration in water with shaking rate of 120rPmin increased to the highest.When the shaking velocity was low,the concentration of NH4+-N in the sea water had a positive relation with the concentration of suspended particulate materials.When the shaking velocity was high,the concentration of NH4+-N in the sea water had a negative relation with the concentration of suspended particulate materials.Itps mainly because that when the concentration of the suspended particulate materials is lower,the release is dominated,so the concentration of NH4+-N had a positive relation with the concentration of suspended particulate materials.When the concentration of the suspended particulate is higher,the absorption is dominated,so the concentration of NH4+-N has a negative relation with the concentration of suspended particulate materials.In the course of the resuspension,the fine grain sediment in the chosen sea water had the most contribution to NH4+-N of the sea water,with the medium and coarse grain sediment as the second and third contributors.The concentration of NO3--N in water had a negative relation with mixture ratios and shaking velocities.The coarse sediment had a similar trend with the fine sediment.The medium grain sediment of the chosen sea area had more contribution to sea water than the coarse and fine sediment.At the beginning of each experiment,the concentration of NH4+-N was high.It showed that the NH4+-N in the sediment had a large release at the beginning.It is because that in the process of freeze-dried,NH4+-N in pore water was adsorbed on the sediment surface,and the force of combination was delicacy.Nitrogen has different forms in sediments,which represent different geochemical characters and has different effects in the cycle in the sediments.So itps necessary to study the effect of resuspension on the concentration of different forms nitrogen in the sediments.In this experiment,KCl 、HAc-NaAc 、NaOH were separately used to extract sequentially ion-exchange form,carbonate form,and their concentrations were measured.NO3--N、NH4+-N mainly came from ion-exchange form,carbonate form nitrogen,and the contribution of iron-manganese form nitrogen was less. |
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| Keywords: | sediment NH4+-N NO3--N resuspension |
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