基于数学模型的AAO系统阶跃响应特性分析

以厌氧/缺氧/好氧(AAO)工艺数学模型为基础,利用灵敏度分析和响应速度从幅度和动力学两方面进行了AAO工艺操作变量的阶跃响应特性分析.结果表明,在AAO系统中,进水流量(Qf)、剩余污泥排放量(WAS)、污泥回流量(RAS)和混合液回流量(MLR)对出水水质的灵敏度较高.其中,WAS的响应速度较慢,适用于系统的长期调整.好氧区溶解氧(DO)适合于出水氨氮的短期调整,RAS和MLR对于出水总氮均是灵敏、快速的变量,RAS会显著影响出水总磷,而MLR对出水总磷影响很小.AAO系统功能性菌群受Qf影响很大.除Qf外,WAS和RAS是对异养菌和自养菌浓度影响较大的变量,聚磷菌浓度对操作变量的灵敏度大小顺序为WAS>MLR>RAS>DO.

Model-based analysis for step response characteristics of the anaerobic/anoxic/aerobic process

An anaerobic/anoxic/aerobic (AAO) process model was developed and applied to obtain step response signals of process variables including influent flow rate (Qf), step feed ratio (SF), dissolved oxygen (DO) in the aerobic zone, waste activated sludge (WAS), returned activated sludge (RAS) and mixed liquor recirculation (MLR). Through sensitivity analysis and response time tests, the effects of these variables on process performance, as well as the dynamic characteristics of these variables were studied. Pollutants concentrations in the effluent were highly sensitive to Qf, WAS, RAS and MLR. WAS demonstrated slow response speed and therefore was suitable for long-term adjustment of the process. DO in the aerobic zone was suitable for short-term adjustment of ammonia nitrogen concentration in the effluent. Total nitrogen concentration in the effluent was sensitive and fast responding to both RAS and MLR. Total phosphorus in the effluent was sensitive to RAS but insensitive to MLR. The functional biomass of the AAO system were greatly affected by Qf. The most effective variables for heterotrophic and autotrophic biomass concentrations were WAS and RAS. The order of sensitivity of phosphorus accumulating organisms to variables was WAS > MLR > RAS > DO.