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Theoretical and practical considerations on optimal design & operation conditions for the step-feed anoxic-oxic activated sludge process

优化设计的理论和实践考虑

基本信息

批准号：
06650611
负责人：
FUJII Shigeo
金额：
$ 1.54万
依托单位：
Ritsumeikan University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

项目摘要

The main objective of this project is to establish the optimal design and operation conditions for the step-feed anoxic-oxic activated sludge process. To achieve this objective, we conducted four kinds of research work, (1) review of experimental reports, (2) stoichiometrical analysis, (3) laboratory experiment and (4) numerical calculation. Then, the following results are obtained :(1) In the work of literature review, more than one hundred experiments were collected from journals and conference proceedings, and the quantitative relationships between nitrogen removal efficiency and many design/operation conditions were obtained.(2) In the stoichiometrical analysis, chemical and biological reactions in reactors were simplified to make all chemical changes the mathematical functions of substrate, DO,NH_4-N,NO_3-N and alkalinity. Then, effluent water quality were formulated with such water quality concentrations in influent and operational conditions such as step ratio and recycle ratio. Consequently, the operational conditions which make the effluent T-N minimum were proposed.(3) To verify the above theory, laboratory tests were conducted more than 20 times with artificial sewage. In a series of experiments, step ratio, recycle ratio and influent intensity were selected as experimental parameters and changed in each run. The experimental results approximately supported the above theory, although some gabs remained a little.(4) Numerical calculation was conducted to explain the gabs between experimental results and theoretical values. The models used for this calculation have 18 variables and express many types of water quality items. The simulation showed the gabs are mainly caused by the reactions related to activated sludge, which were not included in the theoretical analysis.Finally, it was demonstrated that the equations obtained from the stoichiometrical analysis are available to know the optimal conditions for step-feed anoxic-oxic activated sludge process.

本项目的主要目的是建立分步进水缺氧-好氧活性污泥法的最佳设计和运行条件。为了实现这一目标，我们进行了四种研究工作，(1)实验报告综述，(2)化学计量分析，(3)实验室实验和(4)数值计算。在文献综述工作中，从期刊和会议记录中收集了一百多个实验，得到了脱氮效率与许多设计/操作条件之间的定量关系。(2)在化学计量分析中，将反应器中的化学反应和生物反应简化为基质、DO、NH_4-N、NO_3-N和碱度的数学函数。然后根据进水水质浓度和运行工况如阶跃比、循环比等建立出水水质公式。提出了使出水T-N最小的运行条件。(3)为验证上述理论，对人工污水进行了20余次室内试验。在一系列实验中，选择步长比、回流比和进水强度作为实验参数，并在每次运行中进行改变。实验结果基本支持上述理论，但仍有一些GaB存在。(4)通过数值计算解释了实验结果与理论值之间的差距。计算所用模型有18个变量，表达了多种水质项目。模拟结果表明，GABS主要是由与活性污泥有关的反应引起的，理论分析中没有考虑这些反应。最后，从化学计量分析中得到的方程可以用来了解分步进水缺氧-好氧活性污泥法的最佳工艺条件。