活性污泥硝化过程的动态响应信号

Dynamic response signals of nitrification process of activated sludge system

把pH值在线监测与药品自动投加系统与已开发的混合呼吸测量仪集成,组成自动呼吸-滴定测量仪,同时测得废水生物处理过程溶解氧(DO)、pH、氧气利用速率(OUR)和质子变化速率(HVR)。分别监测了只投加NH4+-N底物的活性污泥硝化过程和实验室脱氮除碳SBR曝气阶段的DO/pH响应,结果显示,两信号呈一定规律变化,在反应结束时均会出现明显转折点。对比监测只投加NH4+-N及同时投加COD和NH4+-N的间歇实验中OUR/HVR响应的结果表明,COD的存在及碳氮比的改变会导致OUR和HVR曲线形状明显不同,对同一间歇实验,OUR和HVR变化趋势基本一致,均可用于表征过程动力学。研究成果为硝化过程动态响应监测、过程控制和模型模拟提供基础资料。

A set of automatically respirometric-titrimetric system to monitor simultaneously dissolved oxygen（DO）,pH,oxygen uptake rate（OUR）and hydrogen ion variation rate（HVR） was developed,which consists of the pH monitoring unit,titrant auto-dosing unit and hybrid respirometer.The response signals of DO and pH were monitored under two conditions,respectively the nitrification process with only substrate of NH＋4-N and the aeration period of nitrogen/carbon-removal SBR in laboratory.It was shown that DO and pH changed regularly and there was a turning point at the end of the reactions.In the activated sludge batch tests,the responses of OUR and HVR under the condition with only NH＋4-N added were compared with the responses when both COD and NH＋4-N were dosed.The results showed that the existence of COD and different COD/N ratios will lead to different shapes of OUR and HVR curves,and,in one certain batch test,the change currents of OUR and HVR were roughly the same,both of which could be used to represent process dynamics.The results provide basic data for monitoring,modelling and controlling the dynamic process of nitrification by respirometry-titrimetry.