| 丹江口水库氮磷内源释放对比 |
| 摘要点击 2721 全文点击 878 投稿时间：2018-12-27 修订日期：2019-06-11 |
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| 中文关键词 丹江口水库 氮磷 释放速率 静态培养 Fick扩散定律 |
| 英文关键词 Danjiangkou Reservoir nitrogen and phosphorus release rate static incubation Fick diffusion law |
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| 中文摘要 |
| 利用柱状沉积物采样器在丹江口水库采集不同点位原位柱状沉积物，通过静态培养释放实验及间隙水分子扩散模型两种方法获取沉积物-水界面N和P释放速率，分析水体N和P释放特征.结果表明，不同采样点N和P界面交换速率差异显著.静态培养条件下，5个点位NH4+-N和PO43--P释放速率分别为13.07~24.88 mg·（m2·d）-1和3.06~6.02 mg·（m2·d）-1；分子扩散模型条件下，5个点位NH4+-N和PO43--P释放速率分别为2.67~7.25 mg·（m2·d）-1和0.04~0.18 mg·（m2·d）-1.N和P释放速率总体呈北高南低的趋势，支流N和P最低释放速率分别是主库区最高释放速率的1.48和1.57倍.两种方法均表明郭家山支流N和P的释放速率最高，具有较大内源N和P释放风险.比较两种方法发现，利用Fick定律计算出的界面N和P释放速率明显小于柱样模拟方法得出的结果，N和P的R/F值分别为3.43~4.98和29.67~72.88，这表明用分子扩散模型法进行内源释放速率估算时，偏离真实情况较大，而原柱样静态模拟实验则较贴近真实情况. |
| 英文摘要 |
| In situ sediments were collected at different sites of the Danjiangkou Reservoir using a columnar sediment sampler, and the release rate of N and P at the sediment-water interface was determined through static incubation experiments and the diffusion model of interstitial water molecules. The results showed that there was a significant difference in the release rate for N and P from sediments collected at five sampling sites. The release rates of NH4+-N and PO43--P under static incubation conditions were 13.07-24.88 mg·(m2·d)-1 and 3.06-6.02 mg·(m2·d)-1, whereas those estimated by Fick's Fist Law were 2.67-7.25 mg·(m2·d)-1 and 0.04-0.18 mg·(m2·d)-1, respectively. Overall, the release rates of N and P in the tributaries were 1.48 and 1.57 times higher than that in the reservoir, respectively, and they tended to decrease from the north to the south. The R/F values of NH4+-N and PO43--P were 3.43-4.98 and 29.67-72.88, respectively. The highest release rates of N and P were observed in the Guojiashan tributary for both methods. However, it was found that the release rates of N and P estimated by Fick's Fist Law were significantly lower than those obtained by the simulation method, indicating that the static incubation experiment with intact sediments allowed the release rates of N and P to be closer to the actual situation compared to the interstitial water molecule diffusion model. |
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