平面光极在沉积物—水界面的观测应用研究

发布时间：2018-03-08 02:26

本文选题：沉积物-海水界面　切入点：溶解氧与pH值　出处：《中国海洋大学》2014年硕士论文　论文类型：学位论文

【摘要】：沉积物—水界面是生物地球化学循环的主要界面，掌握界面附近溶解氧(Dissolved Oxygen, DO)与pH值动态分布变化对了解界面化学物质变化对生物地球化学循环过程的影响有着重要意义。鉴于微电极溶解氧与pH值测量方法在获取界面剖面两维信息具有一定的局限性，20世纪70年代新兴的平面光学传感器可以实时记录两维空间的沉积物-水界面化学态变化过程，为揭示沉积物—海水界面的生物与化学环境变化以及生物栖息地的变化过程提供了一种有效的观测手段。本文探讨了基于光强比率的溶解氧测量方法，制备了基于八乙基卟啉铂和香豆素的平面光学传感膜，构建了沉积物-水界面原位模拟试验系统，开展了沉降在海底的水母消亡过程对沉积物-海水界面溶解氧的时空变化影响应用研究，实验结果表明沉降在海底的水母第1天内，沉积物-海水界面的溶解氧消耗速率为0.2mg/L h-1，第2天溶解氧的消耗速率为0.04mg/L h-1。在近海底的水体空间内，第1天的溶解氧消耗速率为0.28mg/L h-1，第2天为0.14mg/L h-1，第3天为0.13mg/L h-1，，证明水母在消亡过程中的3-4天内可在沉积物-海水界面附近形成一个贫氧区，水母消亡过程改变了海底区域的溶解氧分布体系，因此水母爆发后的消亡期可导致海底大面积严重缺氧，对底栖生态系统产生重大影响。针对前期pH值平面光极所采用的，8-羟基芘-1,3,6-三磺酸盐（8-Hydroxypyrene-1,3,6-tri-sulfonic, trisodium salt, HPTS）荧光指示剂由于其自身的亲水性，容易引起荧光指示剂泄露的问题，利用化学修饰方法合成了改性HPTS-TOA亲脂性荧光指示剂，制备了基于亲脂性HPT-TOAS和香豆素的比率法平面传感膜，结合3CCD相机直接记录R\G\B光谱构建了不需要多组滤光片的实用性强的平面光学pH值观测系统，简化了传统的双激励光源，双激发光记录的繁琐步骤，为构建实用化的原位观测系统奠定了基础。
[Abstract]:The interface between sediment and water is the main interface of biogeochemical cycle. It is important to understand the influence of the change of interfacial chemical substances on the biogeochemical cycling process by grasping the dynamic distribution of dissolved oxygen (DO) and pH value near the interface. The two-dimensional information of interface profile has some limitations. In 70s, the new planar optical sensor can record the chemical state change process of sediment water interface in two dimensional space in real time. It provides an effective observation method for revealing the changes of biological and chemical environment and the process of biological habitat change in the interface between sediment and seawater. In this paper, the method of measuring dissolved oxygen based on light intensity ratio is discussed. A planar optical sensing film based on octaethyl porphyrin platinum and coumarin is prepared, and an in situ simulation test system for sediment-water interface is constructed. The effects of sedimentation on the temporal and spatial variation of dissolved oxygen at the interface between sediment and seawater were studied. The experimental results showed that the sedimentation occurred in the first day of the sea bottom jellyfish. The dissolved oxygen consumption rate at the interface between sediment and seawater is 0.2 mg / L h-1 and 0.04 mg / L h-1 on the second day. The dissolved oxygen consumption rate was 0.28 mg / L h-1 on the first day, 0.14 mg / L h-1 on the second day, and 0.13 mg / L h-1 on the third day. The extinction process of jellyfish changes the distribution system of dissolved oxygen in the seabed area, so the extinction period of jellyfish after the eruption can lead to severe hypoxia in a large area of the sea bottom and have a significant impact on the benthic ecosystem. In view of the fluorescence indicator of 8-hydroxypyrene-1sulfonate (8-Hydroxypyrene-1), 6-tri-sulfonic, trisodium salt (HPTSs), which is used in the plane photoelectrode of pH value, it is easy to cause the leakage of the fluorescent indicator because of its hydrophilicity. The modified HPTS-TOA lipophilic fluorescent indicator was synthesized by chemical modification, and the specific method plane sensing film based on lipophilic HPT-TOAS and coumarin was prepared. Combined with 3CCD camera to record R\ G\ B spectrum directly, a plane optical pH observation system without the need of multiple filters is constructed, which simplifies the complicated steps of traditional double excitation light source and double excitation light recording. It lays a foundation for the construction of practical in-situ observation system.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P736.21

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