Ozonation of aqueous Bomaplex Red CR-L dye in a semi-batch reactor

Abstract

The ozonation of synthetic wastewater containing Bomaplex Red CR-L dye has been realized in a semi-batch reactor. In this study, the dye and COD removal from synthetic textile wastewater has been studied by ozonation as functions of initial dye concentration (400, 600, 800 and 1000 mg L −1), temperature (18, 40 and 70 °C), ozone–air flow rate (5, 10 and 15 L min −1), pH (3, 6, 9.3 and 12) and ozone generation percentage (0.7, 1.1 and 1.4 O 3%). The efficiency of dye removal has increased with increasing pH, ozone generation rate, and decreased with increasing temperature, but not changed with increasing ozone–air flow rate and initial dye concentration. The efficiency of COD removal from synthetic wastewater has increased with increasing pH, ozone generation percentage, but scarcely changed with increasing initial dye concentration and ozone–air flow rate, but the efficiency of COD removal decreased with increasing temperature. In this study, dye removal from synthetic wastewater in excess of 99% was obtained at an oxidation time of 15 min. The efficiencies of COD removal were between 56 and 35% at an oxidation time of 30 min. At the end of the study, it was concluded that ozonization is an efficient process for dye removal from synthetic wastewater of Bomaplex Red CR-L, but alone ozonization was not an efficient method to remove all the COD from the textile wastewater.