Comparison of the efficiency of photochemical processes combined with UV/H2O2 and UV/TiO2 in removal of Acid Red 18 from aqueous solutions

Background and Aim: Development of manufacturing industries of textile dyes has resulted in marketing new dyes with better dyeing qualities. Improvement of the dye quality is related to the structural stability of the chromogenic materials which make dyes resistant against chemical and biological dissociation. The purpose of this study was to investigate the efficiency of the photochemical processes combined with UV/H2O2 and UV/TiO2 in removal of Acid Red 18 dye from aqueous solutions in a batch reactor. Material and Methods: This study was an experimental - laboratory study. A reactor was designed and fabricated in our laboratory. Then optimum pH was determined in stable condition. The effect of initial concentrations of hydrogen peroxide, titanium dioxide, contact time, and different concentrations of Acid Red 18 dye were systematically assessed while keeping optimum pH constant. Data were analyzed and interpreted using Excel software and regression coefficient. Results: The results of this study revealed increased removal efficiency of Acid Red 18 in acidic pH in the above mentioned processes; however, this efficiency decreased with increased initial concentration of Acid Red 18 dye. Moreover, the removal efficiency of dye increased by increasing contact time and concentrations of hydrogen peroxide and titanium dioxide. Conclusion: In general, our results showed that the photochemical processes combined with UV/H2O2 and UV/TiO2 could be used as an effective method for removing Acid Red 18 from aqueous solutions. Moreover, comparison of the results indicated that the removal efficiency of the photochemical process combined with UV/H2O2 was higher than that of the photochemical process combined with UV/TiO2. Because of availability, time-effectiveness, and lack of sludge production this process is recommended for removal of Acid Red 18.