Mineralization of 198 Reactive Red Dyes by the Hybrid Advanced Oxidation Process UV/US/H2O2/O3 from Colored Wastewater Using Central Composite Design

The presence of many synthetic dyes in aqueous solutions can cause carcinogenesis and mutagenicity and affect human health. Reactive Red 198 is one of the types of azo dyes with complex structure, toxic, carcinogenicity, mutagenicity properties, and tolerable in the environment, which is discharged to the environment through the sewage of textile industries. This study was performed to determine the mineralization of 198 reactive red dyes by the hybrid advanced oxidation process UV/US/H2O2/O3 from colored wastewater using central composite design.

In this descriptive-analytical study several factors affecting on dye mineralization process including the presence of ozone gas and ultraviolet rays (UV) as well as the initial dye concentration, Ultrasound (US), contact time, pH, and hydrogen peroxide were investigated. Experimental design and optimization were performed by design of experiment software using central composite design and its optimal conditions were determined.

The maximum dye degradation efficiency of 100% was performed under optimal conditions including initial dye concentration of 200 mg/L, reaction time of 34 minutes, hydrogen peroxide concentration of 27 mg/L and pH=9 in the presence of ozone gas flow, ultraviolet rays and ultrasonic waves. Also, the influence of factors on dye removal including ozone, UV, initial dye concentration, US, contact time, pH, and peroxide were  58.8%, 19.3%, 2.3%, 1.5%, 1.1%, 0.6 %and 0.2 % ,respectively.

UV/US/H2O2/O3 hybrid process with advantages such as performance and high speed can be recommended for wastewater treatment in various industries.