Study On Three Phase Fluidized Bed Bioreactor Behavior For The Treatment Of Wastewater

For a long time,activated sludge process which has been widely adopted in municipal sewage biological treatment is the one of most widely used all over the world.It has many advantages such as higher removal efficiency,good effluent quality and stable ecological system in reactors and so on.The paper reasearches and develops a new type of reactor that combines the structural characteristics of Airlift Internal Loop Reactor with activated sludge process.The reactor not only utilizes fully the advantages of technology of activated sludge wastewater treatment,but also improves the inner cylinder of the internal loop reactor.This new type of reactor named Three Phase Fluidized Bed Bioreactor(TPFBR),is built and investigated.The paper studies the effect of activated sludge culture in TPFBR by using the synthetic wastewater.It also studies the treatment effect and influencing factors in carbon and nitrogen removal rate.In addition,the kinetics of substrate degradation is described by utilizing Monod and Haldane equations.The main contents of the dissertation are as follows:(1) The experimental set-up of TPFBR is built,and the cultivation of activated sludge is investigated.(2) The optimal operating parameters and influencing factors of removal rates of COD and nitrogen are confirmed with orthogonal experiment method.The function of simultaneous nitrification and denitrification in the reactor is achieved.Meanwhile,the effect of different methods of adding carbod source on nitrogen removal is investigated.(3).Compared with activated sludge reactor and fluidized bed bio-reactor,TPFBR shows higher and more stable removal efficiency of COD and ammonia nitrogen.(4).The kinetics of the COD degrading process is also sutdied in the paper by using the usual Monod model and Haldene model.The simulation results is in good agreement with the results of experiment,which incicated that the COD degrading process was according with Monod model or Haldane model.The COD degrading process can be described by utilizing Monod and Haldane equations to make contribution to industrialization of wastewater treatment.Based on the continuous running of the experiment for a long time,the paper analyses the operating parameters and influencing factors of TPFBR,determines the optimal scheme and simulates the process of substrate degradation.The dissertation establishes the basis for theoretical analysis and practical application of TPFBR.