This study proposed an integrated technique by reduction coupling with oxidation process in order to acquire simultaneously complete both decolorization and mineralization of orange II under the condition of microwave assisted milling. Experimental variables such as initial dye concentration, iron dosage, microwave power, solution pH and initial H2O2 concentration were systematically studied. Under the optimal operational parameters (100 mg/L aqueous solution of pH 3 containing 400 mg/L H2O2 while controlling microwave power at 400 W), the results showed that the decolorization efficiency is up to 91% after reaction for 2 min and the total organic carbon removal efficiencies were 72.7 and 80.5% at a reaction time of 10 min and 60 min, respectively. It indicated that the decolorization and mineralization of orange II were largely enhanced by the reduction of zero-valent iron in ball milling process and the oxidation of hydroxyl radicals generated by hydrogen peroxide. It suggested that microwave-assisted ball milling technology has potential application for degradation of azo dye in wastewater.
- ball milling
- orange II
- First received 5 July 2016.
- Accepted in revised form 2 March 2017.
- © IWA Publishing 2017