Wastewater Biological Nitrogen Removal Model Based On A~2/O Process

With the much further development of theoretical study about wastewater treatment, people prefer to research the removal mechanism now than study the removal effect of the craft for the pollution. The mathematic model which was thought as the effective instrument in the process of wastewater treatment has appeared much more attention in the experts and scholars. It can help us understand the course the reaction in the craft more easily because of its effective simulation of many complicated biochemical reactions in the system and better descriptions about the contents about the removal mechanism of the reaction process.The characters of A~2/O are good adaptability, efficient removal rate of organic pollution and stable operation results. In real application process, it can be operated simply and the conditions can be controlled easily. The need for the land is relatively less under the condition of same sewage treatment load. It has a strong ability of resisting the impact load and needs less investment. It has been applied widely in real treatment plant because of all the advantages mentioned above. The effluent of the A~2/O craft can meet the requirements of the standard of discharged pollutants for municipal wastewater treatment plant.The effect of A~2/O craft is good for the municipal wastewater, the high concentration of COD in the effluent of the craft is 26.12mg/L while the concentration of COD in the influent is 192.24mg/L, and the average concentration of COD in the effluent is 23.82mg/L, the average removal rate of COD can reach 87.61%. The high concentration of NH4+-N in the effluent of the craft is 0.67mg/L while the concentration of NH4+-N in the influent is 33.14mg/L, and the average concentration of NH4+-N in the effluent is 0.60mg/L, the average removal rate of NH4+-N can reach 98.20%. The high concentration of TN in the effluent of the craft is 13.76mg/L while the average concentration of TN in the influent is 42.18mg/L, and the average concentration of TN in the effluent is 12.33mg/L, the average removal rate of TN can reach 70.77%.We can establish the mathematic model of the A~2/O craft based on the first model(ASM1) of sludge put forward by the International Water Association. We can simulate the mathematic model of the A~2/O craft by the comparison of the effluent of the model and the craft respectively which can help us amend the items that has bigger effect on the simulation effect.The article introduce the model of ASM1, including the aspects of matrix structure,stoichiometric coefficient and kinetic parameter,biochemical reaction process and so on, and put forward the reference value involving to the stoichiometric coefficient and kinetic parameter.According to the establish of the model and base on the AQUASIM software, we can simulate the sensitivity of the A~2/O process by using the sensitivity analysis tools of the software to choose the maximum value, by using the parameter valuation tools of the software to examine the relatively large parameters, after all of these steps, we can get the better imitative effect.We can make a scatter diagram by using the real measured data and model simulated data, the diagram indicate that the concentration of COD,NH4+-N,TN in the real measured effluent and model simulated effluent fluctuated near the function curve y=x, indicating the error of the simulation is in an acceptable range, the simulating results can be trusted.