Degradation of bromoamine acid by BDD technology – Use of Doehlert design for optimizing the reaction conditions

Abstract

The electrochemical incineration of bromoamine acid (BAA), an intermediate of anthraquinone dyes, was conducted using cells containing boron-doped diamond (BDD) anode and Pt cathode under galvanostatic conditions. The effect of input variables, including applied current density (jappl), flow rate, sulfate concentration and initial BAA concentration ([BAA]0), on process performance was assessed implementing a Doehlert experimental design. The foregoing results obtained by response surface methodology led to the following optimal conditions for BAA degradation: jappl of 15.50mAcm−2, flow rate of 550mlmin−1, sulfate concentration of 1.0mM and [BAA]0 of 125mgdm−3, which gave a decolorization rate of 100%, a mineralization rate of 85.29%, a specific energy consumption of 3623.57kWhkg−1 TOC and a mineralization current efficiency of 10.1% at 120min of electrolysis. Under the optimized conditions, BAA decays followed pseudo first-order kinetics. In addition, a possible degradation sequence involving all the detected intermediates was proposed for the anodic oxidation of BAA on BDD electrode. Our results had wide ranging implications for the soft and efficient treatment of BAA polluted wastewater.