Use of Pt and Boron‐Doped Diamond Anodes in the Electrochemical Advanced Oxidation of Ponceau SS Diazo Dye in Acidic Sulfate Medium

다국어 초록 (Multilingual Abstract)

The electrochemical degradation of 2.5 L of Ponceau SS diazo dye solution in acidic sulfate medium has been studied in a pre‐pilot flow plant with a boron‐doped diamond (BDD)/air‐diffusion or Pt/air‐diffusion cell connected to an annular photoreactor. The decolorization and mineralization was enhanced in the order: electrochemical oxidation with electrogenerated H2O2<electro‐Fenton<photoelectro‐Fenton. The two former methods performed better with the BDD anode, whereas the latter yielded similar results for both anodes. From this, the use of less expensive active anodes such as Ti|Pt instead of non‐active BDD for photo‐assisted Fenton‐based electrochemical processes is recommended. In all methods, increasing current density led to a greater degradation rate, but with lower mineralization current efficiency and higher energy consumption. Five primary aromatic products and four final carboxylic acids were detected, along with recalcitrant products poorly removed by hydroxyl radicals and UVA radiation.
Degradation of Ponceau SS dye: Similar decolorization and mineralization rates are obtained with photoelectro‐Fenton by using a pre‐pilot flow plant with a BDD/air‐difffusion or Pt/air‐diffusion cell. Initially, five aromatic products are formed, followed by their conversion into four carboxylic acids, which are transformed into carbon dioxide (see figure).