Performance analysis of photocatalytic reactor with immobilized catalyst for emerging pollutants water treatment using cfd simulation and optimization method

Abstract

An annular labyrinth photocatalytic reactor design was optimized to degrade water emerging pollutants by combining CFD modeling and a Box-Benken experimental design with the desirability function method for the optimization. The optimization was performed by minimizing the pollutant degradation time and the reactor operational cost, varying three factors in the experimental design, the fins number in the labyrinth, the thickness of the annular region, and the solution transmittance. The range of variation levels was 5 to 9, 5 mm to 25 mm, and 35 % to 95 % respectively. The intrinsic kinetic model of the salicylic acid degradation used in CFD simulations takes into account the variations of pollutant concentration and light intensity. Results showed that the transmittance was the most significant factor in minimizing both degradation time and energy cost, followed by the annular reactor thickness and the fins number. The desirability method showed that the combination of the optimized reactor levels was 9 fins, thickness of 25 mm, and transmittance of 95 %. To verify the efficiency gain of the optimized reactor, it was compared the degradation time and the energy cost of the optimized reactor with a conventional annular reactor. The efficiency gain was about 53 %.