The Model Construction And Control Strategy Designing In The WWTP

In recent years, the waste water treatment (WWTP) has become a hotproblem in the environment protection. Then it gets a lot of attention fromthe researchers. The WWTP has many kinds of treatment procedures, wemainly discuss about the active sludge method in this paper because of itsconvenience and low power demanding which make it become the mostpopular waste water treatment procedure in the factories in China. Welearn deeply into the construction and control of the active sludge model,proposing a control strategy using advanced PID controller based on theneural network and the internal model controller based on the neuralnetwork. The following is some results we got in the research:1. Constructing the WWTP simulation platform. The WWTP alwaysneed a long-period to get some result with high pay, most of the labs arenot lucky enough to get a wastewater factory or WWTP experimentalfacility to do such research. In the same time, the WWTP is easilyinfluenced by environmental factor, so it is hard to compare two controlstrategies fairly. Constructing a WWTP simulation platform can solvethese problems, researchers can do experimental simulation on theplatform at any time and get experimental results in a short time;2. Constructing the model of the controlled object with the neuralnetwork. The WWTP is a nonlinear process with complex dynamicproperty, the equation of the controlled object derived from the referencesis so large, which is very hard to control. In this paper, the strong learningability of neural network is used to model the controlled object in theWWTP, then the control strategies can be designed based on the neuralnetwork model; 3. Designing the modified PID control strategies and predictivecontrol strategies based on the neural network. In the waste watertreatment, the microorganism turn ammonia nitrogen into nitric nitrogenunder aerobic environment; and turn nitric nitrogen into nitrogen underanoxic environment, nitrogen can be discharged atmosphere safely. Mostly,the activity of the microorganism is decided by dissolved oxygen. In thispaper, a modified PID controller aimed at controlling the dissolved oxygenhave been designed, it decreases the ammonia nitrogen concentration inthe WWTP process. Then a predictive controller is applied to control thenitric nitrogen which has a direct effect on the outflow equality;4. At the end, we have developed simulation software. The WWTP isa complex process, there are so many the modules in the simulationplatform that we can hardly locate the problem when the system is crushed.In this paper, an integrated software has been developed using the gottenresearch results. This software is clean and can help avoid some crushproblem caused by the researchers. This software has applied a patent.