UV/Fenton photo-oxidation of Drimarene Dark Red (DDR) containing textile-dye wastewater

Abstract

Textile dye wastewater contains organic pollutants which are non-biodegradable, characterized by low BOD/COD ratio of typically < 0.01. Therefore to treat such wastewater, the destructive wastewater treatment methods which can be utilized are the Advanced Oxidation Processes (AOPs). One of the AOPs method which is the UV/H2O2/Fe2+ (or UV/Fenton) offers not only relatively low cost but also quite effective (in terms of color removal and reaction time) treatment. This particular research aimed to optimize the conditions of UV/Fenton photo-oxidation process for Drimarene Dark Red containing textile-dye wastewater. The two main operating conditions to be optimized were the initial concentration of H2O2 ranged between 0.022–0.078 %-w and the mol ratio of Fe2+ : H2O2 was varied from 1 : 13 up to 1 : 45, using the Central Composite Design experimental matrix. The photo-oxidation was carried out at the optimum pH of 3 from some previous experiments. The best processing conditions of the photo-oxidation of Drimarene Dark Red (DDR) were found at the initial concentration of H2O2 at 0.050%-w and the mole ratio Fe2+: H2O2 of 1 : 22. Under these conditions, the measured 2nd order pseudo-rate constant was 0.021 M-1.min-1. The DDR color removal of 90% was surprisingly achievable within only 10 minutes reaction time.