【作者】 王雪；

【导师】 闻建平；

【作者基本信息】 天津大学 ， 生物化工， 2010， 博士

【摘要】 恶臭废气作为大气污染的主要因素,引起世界各国的重视,对其排放有明确规定。生物法因成本低,无二次污染,已成为恶臭废气脱臭技术的热点之一。本文研究鼓泡塔和气升式环流生物反应器恶臭假单胞菌净化恶臭废气中的甲苯废气动态行为并进行CFD模拟,在生物法处理恶臭废气工业应用领域具有指导意义,在三相复杂生物反应过程模型化方面也具有重要的学术研究价值。首先研究鼓泡塔游离菌净化甲苯废气,使出口气体达标排放并优化操作条件。对上述过程进行CFD模拟研究:建立了3D瞬态气-液两相流CFD模型,以MUSIG模型描述气泡尺寸分布,耦合流动、传质和生化反应,以液相速度、甲苯去除率、液相溶氧及甲苯浓度的实验值验证模型,实验值与模拟结果吻合很好;通过该模型预测鼓泡塔内局部流体力学特性和组分浓度场的时空分布,并定量研究传质与反应间的关系,讨论限速步骤。其次研究气升式环流反应器游离菌净化甲苯废气,使出口气体达标排放并优化操作条件。对上述过程进行CFD模拟研究:建立了3D瞬态气-液两相流CFD模型,采用MUSIG模型描述气泡尺寸分布,耦合流动、传质与生化反应,以液相速度、甲苯去除率和液相甲苯浓度的实验值验证模型,可靠性良好;利用该模型预测IALR内局部流体力学特性和组分浓度场的时空分布,并定量研究传质与反应间的关系,讨论限速步骤。第三,研究鼓泡塔固定化菌体净化甲苯废气,使出口气体达标排放并优化操作条件。对上述过程进行CFD模拟研究:建立了3D瞬态气-液-固三相流CFD模型,以MUSIG模型描述气泡尺寸分布,耦合流动、传质与反应,以液相速度、甲苯去除率和液相甲苯浓度的实验值验证模型,吻合良好;用该模型预测鼓泡塔三相生物反应器内局部流体力学参数和组分浓度场的时空分布,并定量研究传质与反应间的关系,讨论限速步骤并进行优化模拟。最后研究气升式环流反应器固定化菌体净化甲苯废气,使出口气体达标排放并优化操作条件。对上述过程进行CFD模拟研究:建立了3D瞬态气-液-固三相流CFD模型,采用MUSIG模型描述气泡尺寸分布,耦合流动、传质与反应,以液相速度、甲苯去除率和液相甲苯浓度验证模型的可靠性;以该模型预测IALR内局部流体力学参数和组分浓度场的时空分布,并定量研究传质与反应间的关系,讨论限速步骤并进行优化模拟。更多还原

【Abstract】 Odorous waste gas as a main factor for air pollution has drawn great attentions of many countries worldwide and the emission standard has been set up strictly. Biopurification has become a hot spot for deodorization with the advantages of non-secondary pollution and low cost. Toluene is used as the target agent for odorous gas in this thesis and experiments and transient CFD modeling of toluene waste gas biodegradation by Pseudomonas putida WQ-03 in bubble column and airlift loop bioreactor have been carried out.First, toluene emissions are purified by suspended Pseudomonas putida WQ-03 in a gas-liquid two-phase bubble column and the operational conditions are optimized to meet the Chinese toluene emission standard of 40 mg/m3. A three-dimensional (3D) transient computational fluid dynamic (CFD) model is established to simulate the transient performance of the biodegradation, with the MUSIG model to describe the bubble size distribution, and with mass transfer equations and biomass intrinsic kinetics. The simulation results agree well with the experimental data, such as liquid velocities, toluene removal efficiency and the liquid phase oxygen and toluene concentration. The developed model is used to predict the hydrodynamic properties and the concentrations of the components of each phase, as well as the discussion of the rate-limiting step for the biodegradation process.Secondly, toluene waste gas is treated by suspended P. WQ-03 in a two-phase internal airlift loop reactor and a 3D transient CFD model is established to simulate the dynamic performance of the biopurification, with the MUSIG model, mass transfer equations and biomass intrinsic kinetics. The model has been verified by the experimental data of liquid velocities, toluene removal efficiency and the liquid phase toluene concentration. The developed model can be used to predict the hydrodynamic properties and the concentrations of the components of each phase. The rate-limiting step in the biopurification is also discussed.Thirdly, toluene waste gas is purified by immobilized P. WQ-03 in a three-phase bubble column reactor and a 3D transient CFD model is established to simulate the dynamic performance of the biopurification, with the MUSIG model, mass transfer equations and biomass intrinsic kinetics. The model has been verified by the experimental data of liquid velocities, toluene removal efficiency and the liquid phase toluene concentration. The developed model can be used to predict the hydrodynamic properties and the component concentrations of each phase, as well as the rate-limiting step which is the optimized simulation based on.Finally, toluene waste gas is purified by immoblized P. WQ-03 in a three-phase internal airlift loop reactor and a 3D transient CFD model is established to simulate the dynamic performance of the bio-purification, with the MUSIG model, mass transfer equations and biomass intrinsic kinetics. The model has been verified by the experimental data of liquid velocities, toluene removal efficiency and the liquid phase toluene concentration. The developed model can be used to predict the hydrodynamic properties and the component concentrations of each phase. The rate-limiting step is also discussed based on which optimized simulation is carried out.更多还原