Simulation Of External Dynamic Membrane Operation Efficiency Bioreactor On Mathematical Model

Dynamic membrane bioreactor(DMBR)had been widely applied to several kinds of wastewater treatment because the advantages of process such as high flux,low energy requirement and high anti-pollution capacity.However,the study of DMBR is still on the pilot scale experiment which had not develop to the level of industrial application.This experiment has built a mathematical model which apply to DMBR.The main contents and results are as follows:The model(ASM 1-DM)was based on the activated sludge model NO.1(ASM 1),included nitrogen,utilization-associated products(UAP),Biomass-associated products(BAP)and extracellular polymeric substances(EPS).The growing process of microbial on UAP and BAP,hydrolysis of EPS were included in the model.The characteristic of membrane filtration was also added in this model.Water quality discharged and the concertration of foulents could be predicted in this model.Respiratory rate measurement and the high ammonia nitrogen load measurement were used for measuring the parameters of ASM1-DM:the yield coefficient for heterotrophic biomass(YH)is 0.725,the maximum specific growth rate of heterotrophic biomass(?H)is 0.372,the decay rate for heterotrophic biomass(bH)is 0.372,the maximum specific growth rate of autotrophic biomass(?A)is 0.47.8 parameters were modified according the comparison of simulation values and actual values of effluent quality and foulants concentration.The dynamic simulation results on modified ASM 1-DM showed that the concentration of sludge and SMP could precisely predicted.The simulation values of effluent COD,BOD,NH3-N,TN were well fitted with experiments values.The composition of sludge in each tank are similar.Organic matter in sludge were fluctuated on account for the variation of influent components.ASM1-DM were applied for designing a high ammonia sewage treatment project and optimum parameters of the project were determined:the best hydraulic retention time was 13.5h,the bedt dissolved oxygen in aerobic tank was 3mg/L and volume ratio of tanks were 1.5:2.5:0.5.The area of dynamic membrane was calculated to 335m2 according to the simulation results on the optimum operating condition.