Removal of azo red-60 dye by advanced oxidation process O3/UV from textile wastewaters using Box-Behnken design

Abstract

• Main effects and synergistic effects in hybrid AOPs improve the treatment textile wastewaters. • Treatment model and optimization of process parameters using RSM based Box-Behnken design model. • The model predicted about 100 % of azo red-60 removal under optimal conditions. • The parameters studied had statistically significant probability critical levels. Azo red-60 dye is a type of azo dyes with complex structure, carcinogenicity and mutagenic properties that are tolerable in the environment and is discharged through the sewage of textile industries. Advanced oxidation techniques have been used to remove resistant organic compounds. Experimental design and optimization were performed by the design of experiment software using Box - Behnken Design, and its optimal conditions were determined. The effects of these parameters were tested, and the dye removal process includes the presence of ozone gas and UV (125 w) as well as the different pH values (5–10) and reaction times (10–60 min), at an initial concentration (25–100 mg/L) were investigated. The ANOVA results with a confidence level of 99 %, high regression, and fitting values were obtained between the experimental degradation data of azo red-60 and the RSM predicted model. The optimum removal efficiency of 100 % was obtained at conditions of an initial concentration dye of 100 mg/L and a reaction time of 60 min and pH 7.5 in the presence of ozone gas flow, and UV rays. Thus, the present study indicated by the O 3 /UV hybrid process with advantages such as performance and high speed can be an efficacious method for removing azo red-60 and wastewater treatment in various industries.