▎ 摘　　要

The use of microreactors in (photo)catalytic processes offers new possibilities for studying and optimizing many mass and photon transfer limited reactions. In this study, we propose a scalable computational fluid dynamics (CFD) model for the prediction of photocatalytic degradation of a model pollutant (4-nitrophenol) using immobilized N-doped TiO2 grown over reduced graphene oxide (N-TiO2/rGO) in a photocatalytic microreactor working in continuous flow-recirculation mode. The mode of operation used in this study allows the reduction of mass transfer limitations inherent to heterogeneous photocatalytic reactions taking place on immobilized catalysts. A CFD model was developed for effective prediction of experimental results using COMSOL multi-physics. The experiment and the model results clearly showed a good agreement. The model parameters were determined through fitting the model with the experimental data, adsorption rate constants were estimated to be 1.76 x 10(4) m(3) mol(-1) h(-1) and 0.0252 h(-1) for monolayer (k(ads,m) and k(des,m)), 1.76 x 10(4) m3 mol(-1) h(-1) and 0.0126 h(-1) for multilayer (k(ads,n) and k(des,n)); and the intrinsic rate constant (k(s)) was 2.02 h(-1). This proposed model herein could serve as a practical tool to improve and optimize an extensive number of photocatalytic reactions for (waste)water applications in microreactors operating in recirculation mode.