Study On The Mathematical Model Of Activated Sludge Particles Based On AQUASIM

Aerobic granular sludge is formed by microbial in aerobic conditions. Because of its advantages of good settling properties, resistance to impact load has become an important research topic in the field of wastewater treatment. With the development of pesticide, the pesticide wastewater treatment has become an urgent problem to solve, so the studying of toxic substances toxic substances using aerobic granular sludge are increasingly important. In this topic, we use AQUASIM software to build aerobic granular sludge mathematical model、floc sludge mathematical model、inhibition model based on Activated Sludge Mathematical No.l (ASM 1). Based on part of the experiment, we study the effect of thiamethoxam (TMX) to sequencing batch reactor (SBR) and removal of various substances in the process of aerobic granular sludge cultivation. At the same time, compared simulated the different inhibition effects level between aerobic granular sludge and floc sludge with TMX. Finally, we study the effect of different chemical oxygen demand (COD) on particle growth and material removal in SBR reactor.The research results show that the activated sludge mathematical model is set up based on ASM1 model has certain practicability and veracity. The toxicity material TMX has obvious inhibitory action for particles growth and organic substrate removal. The total amount of microorganism in particles under inhibition conditions is less than uninhibition conditions. Autotrophic bacteria and TMX degrading bacteria were mainly distributed in the external granule. Heterotrophic is uniform distribution in the grains when there is no TMX inhibition, but under the condition with TMX inhibition, heterotrophic bacteria concentration trend to be high in internal particle, low in external particle.Inhibitory effect of TMX on the floc sludge is significantly greater than the granular sludge. The total amount of autotrophic, heterotrophic bacteria and TMX degradation bacteria in granular sludge were higher than the corresponding total microbial in floc sludge.In a certain range, the higher influent COD concentration is more conducive to the growth of aerobic granular sludge. The simulation results show that the influent COD concentration increased from 300 mg/L to 2300mg/L, the particle size increased from 1.2 mm to 1.7 mm. While in the influent COD concentration increased from 1500 mg/L to 2300 mg/L when the particle size increase is only 0.01 mm, basically no change. At the same time, in a certain range of COD concentration will not affect its removal effect. But the removal effect became significantly worse when COD concentration exceed 2000 mg/L. But along with the increase of influent COD concentration, ammonia nitrogen removal rate reached 90%, the removal effect is not affected.