This work is devoted to the computational fluid dynamics (CFD) simulation of trickle-bed reactors (TBRs) with environmentally based applications on advanced wastewater remediation technologies. Recently, TBRs have assumed a major role in industrial wastewater treatment plants being envisaged as a breakthrough paraphernalia to move forward superseded decontamination processes. According to the literature, the generous research in environmental reaction engineering has indicated that scale-up of TBRs is erroneous if one considers isothermal operation and uses either a pseudohomogeneous or a heterogeneous model with plug flow for gas and liquid phases. Even though an axial dispersion model may account for liquid distribution nonuniformity, the reaction parameters are strongly dependent on the reactor fluid dynamics. In our case-study, first we developed a volume-of-fluid CFD framework which accounts for the surface tension and wall adhesion effects. A three-dimensional computational domain was employed to investigate and validate the multiphase flow model at diverse operating conditions. The catalytic wet oxidation of high-strength phenolic wastewaters was taken as our case study to evaluate axial profiles of temperature and total organic carbon depletion rates. Second, the theoretical calculations were compared against experimental data taken from a TBR pilot plant. The CFD simulations have shown promising results on how fluid dynamics can be correlated with chemical reaction, namely on the prediction of total organic carbon conversions functionalized by nominal liquid flow rates and attained at different temperatures. Finally, the effect of temperature on the spatial distribution studies of liquid phase gave rise to the requirement of higher liquid throughput to achieve sufficient liquid holdup for the same total organic carbon conversions at elevated temperatures.