Model And Optimization Control Of Biological Nitrogen Removal Nitrification Process In Wastewater

The energy consumption produced by aeration in the sewage treatment have occupied a large part of the whole energy consumption, and the dissolved oxygen concentration in the biological degradation process is necessary. So it need to ensure the sewage treatment effect,and make the dissolved oxygen consumption as far as possible under the condition of minimum to reduce running cost. This topic in SBR process as the research background, using the activated sludge model to realize the nitrification aeration optimization control and partial nitrification process optimization control, provides a new way of thinking for sewage aeration optimization.The results show that:(1) By a simplified model of activated sludge, Simplified model can substitute for complicated models. In the biological reaction process such as the changes of dissolved oxygen, the degradation of ammonia nitrogen, the simplified model can correctly simulate the real response change process; And it’s operable to use the simplified model for optimal control.(2) Experiments show that model based control (MBC) is superior to the PID control. Under the condition of guarantee of the treatment effect, The dissolved oxygen consumption in optimal control is far less than the PID control, because the aeration of the model was used to optimize control can predict dissolved oxygen demand, according to the dissolved oxygen microbes need to provide the aeration, and it can effectively save aeration, maximize the efficiency of dissolved oxygen.(3)The realization of partial nitrification is related to many factors, they cannot be isolated on the partial nitrification denitrification start trials, and should be considered from the overall point, the various influencing factors should be combined to analysis. Using the model of optimization analysis method can consider various influencing factors in a comprehensive way.(4) Modeling optimization control can realize partial nitrification and denitrification in 10 days in small-scale, the nitrogen accumulation rate reached 80%. Contrary to generally think of AOB, this experiment found that the KOAOB value was shown to be higher than KONOB, and the FA have significant inhibition effect on the growth of NOB, it is the main reason to realize partial nitrification.