The Modeling Research On Papermaking Mill Middle Wasterwater Treated By Cycle Activated Sludge System(CASS)

Cycle activated sludge wastewater Process (CASS) used to treat wastewater had have several decade years of history until now from 1970's. Which CASS was used for to treat sanitary sewage and the industrial waste, was internationally recognized advanced process in recent years. In the paper, the proess of papermaking mill middle Wasterwater was the CASS, in which the combined the Bioreactor and settling tanker was an important element.Based on Activated Sludge System Model I(ASM1), all kinds of relational expression were studied and combined to form the Cycle Activated Sludge System mathematical model in the paper.Based on the SIMULINK toolbox in MATLAB, some computer program was established to simulate the CASS.The system was designed and developed through the Graphical User Interface (GUI) in MATLAB. Further more, the system forms the user interface through the window, menu, widget, narration and so on. There offer the user all to utilize the mouse or keyboard which can operate expediently. Based on the software, a municipal papermaking mill middle wastewater treatment plant is simulated.First regular data in the Process of papermaking mill middle wasterwater treatment was converted to the data needed to simulate, then model Parameter is adjusted to meet the actual data from the papermaking mill middle wastewater treatment plant. Later dynamic simulation was done by changing in the dissolved oxygen concentration, temperature and sludge reflux ratio.In the CASS pond, the dissolution oxygen concentration, the sludge reflux ratio to the influence of water leakage water quality and the change situation were analyzeed. The results of research showed that simulation based on ASM1 could simulate the performance of cycle activated sludge system in papermaking mill middle wasterwater treatment, and provided valuable references for directing the biological nitrogen removal upgrading.