Comparative studies for the degradation of Reactive Black 5 dye employing ozone-based AOPs

Advanced oxidation processes (AOPs) gain attention for wastewater treatment due to the formation of hydroxyl radicals, which have more oxidation potential. Among all AOPs, few O 3 , O 3 /UV, O 3 /UV/persulfate (PS), and O 3 /catalyst processes were studied to degrade RB5 dye wastewater. Furthermore, the effect of various experimental parameters like ozone flowrate (30–60 LPH), initial pH (2–12), initial dye concentration (100–1000 mg/L), UV intensity (11–66 W), persulfate dosage, and catalyst dosage (0.5–1.2 g/L) was studied for degradation of RB5. Furthermore, the prepared catalyst was characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and BET surface area. Based on the results obtained in the study, the maximum TOC removal efficiency was 96% achieved with optimum operating parameters, 60 LPH of ozone flowrate, 7 pH, 100 mg/L RB5 concentration, and 1 g/L catalyst dosage in 80 min of reaction time using O 3 /catalyst process, while in O 3 /UV/PS process, the total organic carbon (TOC) removal efficiency was 90% with optimum operating parameters, 60 LPH of ozone flowrate, 12 pH, 100 mg/L RB5 concentration, UV intensity 66 W, and TOC/PS ratio 1:40 in 80 min of reaction time. Finally, it can be seen that ozone-based AOPs offered an effective solution for the degradation of recalcitrant pollutants, especially RB5.