Biological Flocculation Adsorption-Hydrolytic Acidification-UCT Combination Process Characteristics And Mathematical Simulation

In this paper,the combined process of Biological flocculation adsorption-Hydrolysis acidification-UCT is used to treat practical sewage.Biological flocculation adsorption is used as the enhanced primary treatment process of sewage to reduce the difficulty of sewage treatment by subsequent UCT process.The hydrolysis acidification tank uses the sludge after flocculation adsorption for hydrolysis to provide sufficient carbon source for sewage treatment by the UCT process and strengthen nitrogen and phosphorus removal.The start-up sequence of the combined process is to start the UCT process,biological flocculation adsorption process,and hydrolysis acidification process in turn.After the stable operation of the combined process,the three hydrolysis processes and sludge adsorption processes in activated sludge No.1（ASM1）and activated sludge No.2（ASM2）are simulated and analyzed dynamically by using the corrected combined process model to find the optimal operation conditions in the operation process.1.For the sludge culture of the UCT process,the continuous culture scheme shall be used after intermittent culture for a period of time.After one week of intermittent culture,continuous cultivation and domestication of sludge will start when the sludge concentration reaches 1500 mg/L.During the domestication of sludge,the influent flow is adjusted to 15 L/h,the continuous inlet and outlet and continuous reflux of the UCT process,and the reflux ratio is 100%.The indicators of pollutants in the effluent are monitored every day.When the discharge standard is met,it indicates that the domestication is successful.After the successful cultivation and domestication of sludge,the biological flocculation process and hydrolysis acidification process shall be started and operated,respectively.2.After the stable operation of the combined process,the average removal rates of COD,NH₃-N,TP,and TN in sewage by the combined process are 83%,86.48%,97.63%,and 63.14%,respectively.Compared with the operation of the UCT process only,the removal effect of pollutants is better.3.The combined process model is based on the ASM1 model,adopting aerobic,anaerobic,and anoxic hydrolysis processes.The combined process model is expressed in the form of the matrix,and the material balance is calculated in the combined process.AQUASIM2.0 is a software simulation platform for programming and solving.In order to make the simulation of the model closer to the absolute value of the actual operation,the parameters with high sensitivity are analyzed,respectively,and the parameters with high sensitivity are estimated according to the results of the parameter sensitivity analysis.4.The mathematical model was used to optimize the combined process parameters,and three different factors were controlled and adjusted:nitrification liquid reflux ratio,sludge reflux ratio,and anoxic liquid reflux ratio.The simulation results show that when the reflux ratio of nitrification solution is 100%～300%,the pollutant removal by the combined process is positively correlated with the reflux ratio,but when the reflux reaches 300%,the denitrification effect of the combined process is poor;When the sludge reflux ratio is controlled,the effect of pollutant removal by the combined process is almost the same.When only controlling the reflux ratio of anoxic solution to 100%～300%,the removal rate of total nitrogen by the combined process increases gradually with the increase of the reflux ratio of the combined process.If the reflux ratio continues to increase,the removal of pollutants does not improve.5.The orthogonal experimental simulation analysis of the combined process is carried out.It is found that the optimal working conditions of the combined process are an anoxic liquid reflux ratio of 300%,nitrification liquid reflux ratio of 300%,and sludge reflux ratio of 80%.Figure[48]table[16]reference[91]...