Aerobic Granular Sludge System Constructed By Mycelial Balls And Its Flow Simulation

In recent years,many researchers and engineers have improved and innovated new activated sludge methods,such as aerobic granular sludge,in the traditional activated sludge process to efficiently remove pollutants and achieve sludge reduction.The purpose is to alleviate the problem of serious pollution of the water resources in China and the large amount of excess sludge produced.However,there are also certain problems with cutting-edge new technologies,which make it difficult to apply practical projects and it is difficult to implement them.Therefore,after analyzing the disadvantages of slow start-up and unstable operation of aerobic granular sludge,a kind of artificial aerobic granular sludge was constructed using a mycelial sphere as a carrier to accelerate the start of aerobic granular sludge reactor.The Computational Fluid Dynamics model was used to simulate the aerobic granular sludge reactor.Through related technology processing,a more intuitive and comprehensive flow state information was obtained and compared with the actual reactor operating conditions.Provide valuable experience and theoretical support for the practical engineering application of aerobic granular sludge system.The addition of fillers to the aerobic granules-accumulating reactor to accelerate the formation of granular sludge has been confirmed in the research.According to the research results of this group,adding biological fillers to the system-the hyphae balls will accelerate well The formation of oxygen particulate sludge,but the rapid propagation of mycelial pellets is the biggest bottleneck that plagues this technology.Based on this study,the conditions for rapid propagation of mycelium pellets were studied.In order to rapidly cultivate a large number of mycelial spheres,the present study focused on the preservation time of spore suspension,the carbon source of the mycelial pellet medium,the initial p H,the inoculum amount and the influence of different metal elements on the mycelium culture,and the spore suspension was obtained.The liquid storage time was less than 15 days,the ratio of glucose to sucrose was 1:4,p H=6,the inoculation amount was 104 cfu/m L,and the metal element used Mg²⁺ as the best rapid propagation conditions.The feasibility and method of artificially constructing aerobic granular sludge by using mycelial spheres as carriers have also required certain exploration experiments.According to the formation mechanism of aerobic granular sludge,two methods ofco-cultivation method and adsorption method were proposed to compare the formation of particles.The feasibility of the two methods was judged by morphology,biomass,average particle size,and completeness.Finally,an optimum adsorption result with a dry weight ratio of mycelium pellets to activated sludge of about 50% was obtained.And actually run the reactor with this condition.Two reactors with different configurations were designed to study the effects of reactors of different configurations on the formation of aerobic granular sludge.Routine water quality indicators were monitored through low-load artificial water distribution and intermittent operation reactors,reflecting the stability of the reactor operation.The characteristics of the sludge were monitored and the effects of reactors with different configurations on the characteristics of the particles were compared.According to the experimental results,the sludge in the square reactor has a tendency to form particles more than the round reactor.On this basis,the two reactors were simulated numerically,and the flow states in the two reactors were fully demonstrated from the perspective of the fluid mechanics model.Corresponding to the real experimental results,the aerobic granular sludge could be more suitable for cultivation.The flow state in the reactor provides technical support for the promotion and application of this technology.