Ozonation of the Acid Red 73 Dye Wastewater with High-Salinity in a Rotating Packed Bed

The presence of high concentrations of inorganic salts significantly challenges the treatment of dye wastewater. This study employed the high-gravity ozonation technology to degrade the Acid Red 73 (AR73) dye wastewater with high-salinity. A high-gravity device – a rotating packed bed (RPB), was used as the reactor for the treatment of the AR73 wastewater with ozone. The impact of inorganic salts, including K2HPO4, (NH4)2SO4, Na2CO3, NaHCO3, and Na2SO4 with concentrations up to 50 g/L, on the treatment effect of the wastewater in the RPB/O3 process was investigated. The liquid detention phenomena in the RPB were also explored to enhance the treatment of the AR73 wastewater. It was found that with the AR73 concentration of 300 mg/L and Na2SO4 concentration of 30 g/L in the wastewater, the optimal treatment effect was achieved at the detained liquid volume of 150 mL, with the ozone absorption, AR73 and COD removal rates reaching 75.7%, 91.3%, and 32.4%, respectively, representing increases of 103.5%, 34.9%, and 106.3% compared to those without liquid detention. The RPB/O3/liquid detention process provides an efficient method for the treatment of high-salinity dye wastewater.