【作者】 尹涛；

【导师】 韩博平；

【作者基本信息】 暨南大学 ， 环境科学， 2007， 硕士

【摘要】 磷是淡水水体生态系统中浮游植物生长的主要的限制性因子，磷的循环是生态系统中最重要的物质循环之一。磷循环过程不仅影响水质，也会影响富营养化的发展，因此了解水库生态系统中的磷的循环状况，对于管理和治理水库水体的富营养化有着重要意义。本文以热带典型抽水水库为对象，通过室内模拟实验和水体中的原位实验，测定水体磷的沉降与释放，并分析了影响磷释放的主要因素与特点。在模拟实验中，从水库两个水域采集柱状底泥，利用柱状管首先进行春夏季节转换期间磷释放的模拟实验；然后利用自行设计的释放装置进行了受控（温度和厌氧状态）条件下的磷释放模拟实验。在水库中利用自行设计的释放装置进行原位磷释放速率的测定，利用沉积物捕捉器捕获悬浮沉降物测定沉降速率和沉降物迁移速率。水库底泥在大部分时间内处在厌氧环境下，大坝区沉积物总磷释放速率明显高于其他区域，进水口处磷释放速率最大，为4.09 mg·m^-2·d^-1。根据测定的释放速率估算，水库全年大约释放100kg的磷，对水库水体中磷的浓度有较大的影响。春夏季节转换期间，大坝区和库中最大总磷释放速率达到3.24mg·m^-2·d^-1和0.62mg·m^-2·d^-1。在磷的释放过程中，上覆水的pH值下降，氧化还原电位升高。在大坝区域沉积物的磷释放的室内模拟实验中，总磷释放速率为3.28mg·m^-2·d^-1，可溶性总磷1.43mg·m^-2·d^-1，溶解性磷为0.65 mg·m^-2·d^-1。磷的释放速率与原位释放相当。释放装置中水体的氧化还原电位从-20mv缓慢升高到18mv后，然后保持基本稳定。上覆水pH值从8.5逐渐降低到7.0左右。根据沉积物捕捉器捕获的沉积物分析，不同水域的总磷沉积速率是不同的，其中进水口沉降速率最大，出水口沉降速率最小。大坝区、沉降区、治理区和出水口等4个区域的平均沉积速率分别为51.88 mg·m^-2·d^-1，14.40 mg·m^-2·d^-1，13.97mg·m^-2·d^-1和9.30mg·m^-2·d^-1。从抽水入库口到出水口处总磷沉积速率呈明显的下降趋势，说明生态工程具有明显的促沉降作用。更多还原

【Abstract】 Phosphorus is a limiting element of phytoplankton growth in freshwater ecosystem. Phosphorus cycle plays an important role in ecosystem function. It affects not only water quality but also the development of eutrophication. To understand the details of phosphorus cycle is important to manage and control the eutrophication of water bodies. The reservoir studied in this dissertation, Dajingshan reservoir, is a typical pumped storage reservoir located in tropical regions. Simulating experiments in the laboratory and in situ experiments were carried out to explore phosphorus release and settling rates and their affecting factors in the reservoir.Core sediments were collected from near the dam and the central part of the reservoir to simulate the phosphorus release in the seasonal transition from spring to summer. Another core sediment from near the dam was used for simulating experiments of phosphorus release under controlled temperature, in which the release device was improved. The similar device was also applied for in situ experiments for phosphorus release. The sediment traps were located in four sites to measure the phosphorus downward flux and settling velocity.From the in situ experiments, we found that the sediment was anaerobic over 300 days every year. The release rate of phosphorus near the dam was 4.09 mg·m^-2·d^-1, higher than in the other sites. In total, about 110 kg phosphorus was estimated to release from the reservoir bottom, contributed 15％to the total loading.In the seasonal transition from spring to summer, the release rate of total phosphorus near the Dam and at the central zone of the reservoir was 3.24mg·m^-2·d^-1 and 0.62mg·m^-2·d^-1, respectively. In the simulated experiments under the controlled temperature, the release rate of total phosphorus, the total dissolved phosphorus and soluble phosphorus is 3.28mg·m^-2·d^-1, 1.43 mg·m^-2·d^-1 and 0.65 mg·m^-2·d^-1, respectively. These release rates were very close to that from the in situ experiments. During the experiments, the redox slightly increased from -20mv to 18mv, and pH showed a decrease from 8.5 to 7.0.The settling rates of particle phosphorus were measured at 4 zones from the inlet of pumped water to outlet for drinking water supply. The phosphorus downward flux tended to decrease along the four sites. The downward flux is 51.88 mg·m^-2·d^-1 at the Inlet and 9.30 mg·m^-2·d^-1 at the outlet.更多还原