STRATEGY FOR OPTIMUM MANAGEMENT OF WATER PURIFICATION SYSTEM WITH CONSIDERATION OF TOTAL ENVIRONMENTAL LOAD AND COST-BENEFTT

为了减少水库蓄水过程中有机污染物的负荷，采用现场实测和水质数值模拟的方法，研究了沿岸的带人工湿地曝气、选择性取水和植被等净化系统的性能。重点研究了溶解氧、营养盐和有机物的行为，建立了水质模型，考虑了水质平衡中的各种生化过程，从而反映了水质的季节变化。仔细确定模型参数，以便准确地再现现场数据，其中溶解氧平衡与hypolimnetic曝气被考虑在内。曝气系统是一个微气泡曝气单元，能够产生具有高溶解度的细小气泡。除曝气外，还考虑了选择性提取操作以调节溶解氧分布。各类系统运行场景， 关于我们 重新假设相对于曝气和选择性撤回，以最大限度地提高水净化性能。优化系统运行的基本思想是使水系统和大气环境的总环境负荷最小化，并使成本效益最大化。在成本效益分析中，考虑了系统建设所需的初始成本和运行成本。提出了反映水质净化性能、成本和总环境负荷的参数，从而最终提出了曝气系统和选择性排放装置的最佳运行策略。对曝气系统进行了间歇运行的现场试验，以寻求最佳的运行成本，通过考虑氧的溶解度和损失，这取决于热结构的季节性变化的性能操作。通过水质测试，找出了间歇曝气系统的最佳运行方式，该系统能最大限度地降低能耗和二氧化碳排放，作为水质净化的另一种方式之一，通过野外调查，研究了天然湖泊沿岸的植被对养分的吸收能力，为水库大坝管理提供了新的方向，对于未来几年的环境工程使用非常有用。此外，通过应用本研究成果，可以最大限度地减少河流流域的总环境负荷。少

In order to minimize the organic compound loads on a reservoir impoundment, performance of water purification systems including hypolimnetic aeration, selective withdrawal and vegetation in littoral zones were investigated by making field measurement and a numerical simulation of water quality. Focus was placed on behaviors of dissolved oxygen, nutrients and organic matters.A water quality model was developed so that seasonal variation of water quality by considering various biochemical processes involved in the water quality balance. Model parameters were carefully determined so as to accurately reproduce the field data, where dissolved oxygen balance associated with hypolimnetic aeration was taken into consideration. The aeration system was a micro-bubble aerator unit that is able to generate fine bubbles with high solubility. In addition to the aeration, selective withdrawal operation was considered to regulate dissolved oxygen profile. Various types of system operation scenarios we … More re assumed with respect to aeration and selective withdrawal in order to maximize water purification performance. The basic idea for optimizing the system operation is to minimize total environmental loads not only on the water systems but also on the atmospheric environment as well as to maximize the cost-benefit. In the cost-benefit analysis, the initial cost necessary for the system construction and the running cost were taken into consideration. Parameters indicating the water purification performance, the cost and the total environmental loads were proposed so that an optimum strategy for the operation of the aeration system and the selective withdrawal devices was finally proposed.On the other hand, an in-situ experiment on intermittent operation of the aeration system was carried out in order to find the best cost-performance operation by considering solubility and loss of the oxygen that is dependent on the seasonalvariation of thermal structure. The best operation of the intermittent aeration system was found through water quality measurement, which is able to minimize the energy consumption and emission of carbon dioxide.As one of another ways of the water purification, nutrient intake performance of vegetation in littoral zone was investigated through a field survey in a natural lake.The results from the present research program are to provide a new direction of dam reservoir management that is useful for environmental engineering use in the next years. Additionally, the total environmental loads on a river catchment can be minimized by applying the present research results. Less