The membrane aerated biofilm reactor (MABR) has demonstrated a huge potential in wastewater treatment plants (WWTPs) due to biofilm stratification and high oxygen transfer efficiency. However, an inappropriate design can negatively impact hydrodynamic and mass transfer, hampering the reactor performance. This work is intended to enhance these phenomena through a rational design of inlet flow distributors (IFD) using computational fluid dynamics (CFD) and mass-transfer simulations. Different IFDs are analyzed at macro and micromixing levels using the residence time distribution (RTD) test and CFD, respectively. It is found that the computed RTD curves agree with experimental data with an error <5 %. The conical wall distributor generates the most homogeneous velocity in the entire reaction zone (membrane zone). The maximum velocity ratio between the channeling and stagnant zones presents a diminution of ∼70 %, and an increment of ∼11.7 % on the chemical oxygen demand (COD) removal if compared against the MABR without IFD, during the sewage treatment. Results show an acceptable agreement of simulations and experimental data, indicating that this approach is satisfactory to conduct a rational design of this type of reactor.

膜曝气生物膜反应器（MABR）由于生物膜分层和高氧气传输效率，在废水处理厂（WWTP）中显示出巨大潜力。但是，不合适的设计会对流体动力和传质产生不利影响，从而影响反应堆性能。这项工作旨在通过使用计算流体力学（CFD）和传质模拟对进气流量分配器（IFD）进行合理设计来增强这些现象。分别使用停留时间分布（RTD）测试和CFD在宏观和微观混合水平上分析了不同的IFD。发现所计算的RTD曲线与实验数据一致，误差＜5％。锥形壁分配器在整个反应区（膜区）中产生最均匀的速度。在污水处理过程中，与没有IFD的MABR相比，通道和停滞区之间的最大速度比减小了约70％，化学需氧量（COD）的去除增加了约11.7％。结果表明模拟和实验数据是可以接受的，表明该方法足以进行此类反应器的合理设计。