Abstract:
In view of the current problems of high cost and low efficiency of traditional aquaculture wastewater treatment process, integrated sewage treatment equipment has attracted much attention because of its low investment cost, small footprint and good treatment effect. An integrated sewage treatment system based on CFD simulation technology using hydrodynamic recycling was designed. By optimizing the pond structure and changing the recycling mode of sewage biochemical treatment unit, the use of kinetic energy equipment was reduced. The fuzzy adaptive PID control system was applied to aeration system in order to intelligently control the concentration of dissolved oxygen in each unit and reduce the fluctuation of dissolved oxygen in biological reaction tank. The simulation results show that the velocity distribution of tank body profile is more uniform, and the circulation of fluid is beneficial to avoid the formation of dead water zone and reduce sludge deposition, in the case of the opening ratio of anaerobic pool to anoxic pool and anoxic pool to aerobic pool is 4:1. According to the analysis of continuous monitoring data, the integrated equipment ran stably, the removal rates of COD, TN and ammonia nitrogen reach 98.66%, 96.43% and 98.57%, and the fuzzy adaptive PID control system could save 20% energy consumption after controlling dissolved oxygen.