低B/C污水对A^(2)/O工艺的冲击仿真模拟

SIMULATION OF IMPACT OF LOW B/C SEWAGE ON AN A~2/O PROCESS

基于深圳市某污水厂A^(2)/O工艺与进出水在线监测数据,使用GPS-X软件建立、校正A^(2)/O仿真模型并论证了模型的可靠性。提出持续冲击模拟和随机冲击模拟2种冲击模拟方案,模拟了2种因总COD溶解惰性组分占比(frsi)升高导致的低B/C污水冲击A^(2)/O工艺的方式。模拟结果表明:A^(2)/O工艺受到低B/C污水冲击时,TN、TP、COD依次超标,投加碳源可降低TN、TP的超标率,降低好氧池溶解氧浓度可节省碳源投加量,TN、TP的最低超标率小于COD。若以模拟时间内5%的COD超标率为阈值,则A^(2)/O工艺最多可承受frsi=0.133、B/C=0.332污水31d持续冲击,或frsi=0.136、B/C=0.330污水的25 d,frsi=0.143、B/C=0.328污水的20 d,frsi=0.151、B/C=0.324污水的15 d,frsi=0.161、B/C=0.319污水的10 d,frsi=0.189,B/C=0.308污水的5 d随机冲击。

Based on the A~2/O process of a sewage plant in Shenzhen and its on-line monitoring data of influent and effluent,the A~2/O simulation model was established and corrected by using GPS-X.The reliability of the model was demonstrated.Two impact simulation schemes,continuous impact simulation and random impact simulation,were proposed to simulate two ways of low B/C sewage impact on A~2/O process due to the increase of proportion of dissolved inert component(frsi) in total COD.Simulation results showed that TN,TP and COD concentration of effluent exceeded the standard in turn when A~2/O was impacted by low B/C sewage,and adding carbon source could reduce the exceeding rate of TN and TP.Reducing the dissolved oxygen concentration in aerobic tank could save carbon source dosage and the minimum exceeding rate of TN and TP was less than COD.When taking the over-standard rate of COD of 5% during the simulation time as the threshold,A~2/O process could withstand the continuous impact of sewage with frsi=0.133 and B/C=0.332 for 31 days,or the random impact of sewage with frsi=0.136 and B/C=0.330 for 25 days,sewage with frsi=0.143 and B/C=0.328 for 20 days,sewage with frsi=0.151 and B/C=0.324 for 15 days,sewage with frsi=0.161 and B/C=0.319 for 10 days,and sewage with frsi=0.189 and B/C=0.308 for 5 days,namely.