CAST工艺运行优化和控制研究

Study on Operational Optimization and Control of CAST Process

根据扬州市汤汪污水处理厂CAST工艺的设计参数及运行情况,利用活性污泥模型ASM2D建立了符合该污水厂实际运行状况的水质模型,分别对不同水温、曝气时间、DO浓度等控制参数下的模拟结果进行定量预测。结果表明,当水温较低时,需确保曝气阶段的DO达到2mg/L或增加曝气时间,以弥补低温对微生物活性的不利影响;当水温较高时,应根据进水水质、水量及模拟结果选择最佳调控参数,以提高出水水质和避免能源浪费。另外,根据CAST工艺优化诊断结果建立了生物工艺智能优化控制系统,使优化成果得以执行实施,从而实现了污水处理厂自动化控制下的节能减排目标。

According to the design parameters and operation situation of the CAST process in Yan- gzhou Tangwang Wastewater Treatment Plant （ WWTP）, the water quality model fitting for the actual op- eration of WWTP was established by means of the activated sludge model （ASM2D）. It can predict the effluent quality under different control parameters like water temperature, aeration time, dissolved oxygen and so on. The stimulation results show that at low water temperature, DO concentration in aeration stage needs to reach 2 mg/L or aeration time is increased to compensate for the influence of low water tempera- ture on bacterial activity. At high water temperature, the optimal control parameters are selected accord- ing to the influent quality and quantity to improve the effluent quality and save energy. In addition, based on the optimized diagnosis result of CAST process, a bioprocess intelligent optimization system was estab- lished to implement the optimization result, thus achieving energy saving and emission reduction under the automatic control of WWTP.