| Recently, the urban wastewater treatment in China was progressed quickly, due to the development of the economy and society. The volume of the wastewater treated was increased, the kind of treatment technology was improved and the management objective of the WWTPs was enhanced. In order to satisfy the more and more strict requirements, the automatically control system is needed for a WWTP to replace the manual operation means. The automatically control system is proved that is an effective and economical method to get the better effluent quality and less operation cost.The selecting or designing control strategies appropriately is the basic of the good performance of a control system. Unfortunately, there are not systemic ways and tools to guide it. A frame of aided design system for WWTP atomatically control strategies is built up in this study. The main contents are establishing a method to develop the database of control strategies, and planning an arithmetic to screen the strategies. In fact, the database is the theoretical foundation of the control system, while screening arithmetic is the key tool.The development of the database includes setting up the classing fashion and getting the describing manner. The database is divided into two sub-databases, and each is described in an uniform way. We also make a performance index to evaluate the local control strategies from two aspects: standard achievement and operation stability. The plant-wide control strategies are gained with plant generalization and correlativity analysis.When planning the screening arithmetic, firstly we construct the physics basic, and then give out the screen processes for local strategies and plant-wide strategies, respectively. The hardware and investment inclination are most important factors for choosing the local strategies, when the instruments and equipments are limits for plant-wide strategies.Depending on the frame and technique specific characters, we finish a control strategy database for typical A-A-O technique, and show the process of evaluating the local strategies. Besides, we apply the specific database and the screening arithmetic to the Xiao Honmen wastewater treatment plant as a demonstration project. At last, one of the strategies is tested in the plant, and it is observed that the treatment effect is improved and aeration cost is saved, especially for NH4-N removal. |
