Treatability of simulated reactive dye-bath wastewater by photochemical and non-photochemical advanced oxidation processes

A number of photochemical and non-photochemical advanced oxidation processes were employed for the treatment of simulated dyehouse effluents containing six commercial reactive dyestuffs and various assisting chemicals at concentrations typically found in the textile dyeing and rinsing process stages. Effects of oxidant (H2O2) and catalyst (Fe2+-ion) dose on decolourization kinetics, reduction in UV254nm and DOC were evaluated for each oxidation process. Treatment efficiencies were also assessed in terms of EE/O and EE/M values to compare electrical energy requirements of the investigated AOPs. UV-light assisted treatment processes were found more effective in DOC and UV254nm removal, whereas the non-photochemical O-3/OH- and O-3/H2O2. oxidation systems were significantly faster in decolourization of the dyehouse effluent than the H2O2/UV treatment process. Results clearly revealed that once optimal reaction conditions were established, the inhibiting effect of the complex wastewater matrix could be overcome and dyehouse effluent ingredients degraded successfully by all examined AOPs at feasible treatment times and electrical energy consumption.