Numerical Simulations for the Enhanced Hybrid Biofilm Activated Sludge Process
|School||Harbin Institute of Technology|
|Keywords||hybrid process activated sludge model No.1 (ASM1) empirical equation modified Newton method numerical simulation|
As the complication and diversification of the environmental problem aggravate, more and more build plants and new build plants need to improve ability of remove organic substance, nitrogen and phosphorus. The single activated sludge process or single biofilm process is not able to do wastewater treatment. So in recent years, the activated sludge- biofilm process developed quickly, it can do wastewater treatment better than the single one. With the development of computer techniques, computer simulation has used to the environmental engineering more than before. It can be used to forecast the wastewater treatment.The project is concerned with the activated sludge-biofilm process of Buji wastewater treatment plant in Shenzhen. Our aim is to set up a mathematical model of the process, use computer language, and do numerical simulation of the removal of the carbon and nitrogen in the water. First, we study the mechanism and mathematical structure of the activated sludge model No.1 (ASM1). Second, we study the empirical equations based on the activated sludge-biofilm model, so as to incorporate the empirical equations into the ASM1. We have the complex mathematical model which can simulate the removal of carbon and nitrogen. We use the modified Newton method to solve the equations. We write program and adjust parameters to get the simulated result.The main contents include:(1)Set up complex mathematical model. Study the activated sludge mathe- matical model and the biofilm mathematical model. We study the processes, parameters and components of the activated sludge mathematical model particularly, and also we study the mechanism of the biofilm mathematical model. We put the empirical equations into the ASM1, and set up a series of dynamics equations of the complex model.(2)Transform the data. According to the water quality of the wastewater treatment plant, and literature reference, we set up the transform relationship of the measured data and simulated data. We put the COD, NH3-N and total Nitrogen values measured into the 15 components of the model.(3)Adjust parameters. By the emulator, we check the parameters default values putted in, in order to make the model simulate the operation of the wastewater treatment plant exactly. By the sensitivity analysis, we know the parameters that effect the plant are KOH、KOA、KNH、YH、YA、ηg、ηh、μA、bA、bH、fp、iXB、qm,COD,sp、qm,nitr,sp, so we adjust these parameters.(4)Compare the measured results and the simulated results. It can simulate the removal rate of the COD and nitrogen well.In the paper, we set up the complex mathematical model in the actually wastewater treatment plant Buji, and we transform the data and adjust the parameters, finally we obtain the better simulation result. It gives a theoretic instruct to the run of the plant.