Photocatalytic process augmented with micro/nano bubble aeration for enhanced degradation of synthetic dyes in wastewater

This research combines TiO2 nanopowder photocatalyst (TNP) with micro/nano bubble aeration (MNBA) to enhance the dye degradation of the photocatalytic process treating synthetic dye wastewater. The experimental synthetic dyes were indigo carmine (IC) and reactive black 5 (RB5). The dye degradation performance of the photocatalytic process without MNBA (TNP + UVA) and with MNBA (TNP + UVA + MNBA) under various initial dye concentrations were evaluated. The results showed that, given the initial IC and RB5 dye concentrations of 2 mu M, the degradation efficiency of TNP + UVA and TNP + UVA + MNBA were 100%. With higher dye concentrations (4-10 mu M), the degradation efficiency of TNP + UVA and TNP + UVA + MNBA were between 84.05-98.20% and 90.64-100%. The kinetics of the photodegradation reaction of both dyes were described by the Langmuir-Hinshelwood kinetic model. The pseudo first order degradation rate constants of the photocatalytic process with MNBA were 1.44 and 1.66 times higher than those without MNBA for IC and RB5.