Study On Mathematical Modeling Of Cyclic Activated Sludge System Based On I-ASM1

Nowadays, as the degree of attention to environmental issues is growing, the investment in environmental protection has gradually increased, and the popularity of the wastewater treatment plant is also more extensive. However, due to the late start of China’s sewage treatment, most of the wastewater treatment plant is still facing a lot of problems. For example, how to improve the process on the minimum amplitude to meet the increasingly stringent water quality requirements; How the wastewater treatment plant to take appropriate measures timely to deal with changes of water quality and how to coordinate the whole river basin planning and management. To solve these problems, improved model I-ASM1 that can accurately simulate pollutant reductions situation was established based on activated sludge model 1. The optimum operating condition of CASS process was determined based on the results of the simulation model and combined with the orthogonal test and energy analysis.Based on the ASM1 model, this study introduced SMP and EPS growth metabolism and the competition between heterotrophic and autotrophic bacteria to establish a new mechanism model. The matrix of I-ASM1 model was finished by adding three new components(SUAP、SBAP、XEPS) and the reactions of microbes growth using SMP and EPS hydrolysis to ASM1 model and adding the inhibition function of organic carbon source to autotrophic bacteria growth into the switch function, and then was solved by Matlab. In order to improve the applicability of the model, sensitivity analysis of the model parameters was done respectively for the removal rates of effluent COD, NH3-N and TN and the concentration of SMP and EPS. According to the analysis results, the high sensitive parameters were adjusted to make the simulation value and the measured value be more consistent.I-ASM1 model checked well was used to dynamic simulation, which simulated the effect of water quality and working conditions of CASS process for the removal of single pollutant. According to the results and the analysis of orthogonal experiment, the optimal reduction of CASS process was determined, which would made the wastewater treatment plant be more efficient.