The electrocatalytic degradation of 1,4-dioxane by Co–Bi/GAC particle electrode

Efficient degradation of industrial organic wastewater has become a significant environmental concern. Electrochemical oxidation technology is promising due to its high catalytic degradation ability. In this study, Co-Bi/GAC particle electrodes were prepared and characterized for degradation of 1,4-dioxane. The electrochemical process parameters were optimized by response surface methodology (RSM), and the influence of water quality factors on the removal rate of 1,4-dioxane was investigated. The results showed that the main influencing factors were the Co/Bi mass ratio and calcination temperature. The carrier metals, Co and Bi, existed mainly on the GAC surface as Co₃O₄ and Bi₂O₃. The removal of 1,4-dioxane was predominantly achieved through the synergistic reaction of electrode adsorption, anodic oxidation, and particle electrode oxidation, with ·OH playing a significant role as the main active free radical. Furthermore, the particle electrode was demonstrated in different acid-base conditions (pH = 3, 5, 7, 9, and 11). However, high concentrations of Cl^- and NO₃^- hindered the degradation process, potentially participating in competitive reactions. Despite this, the particle electrode exhibited good stability after five cycles. The results provide a new perspective for constructing efficient and stable three-dimensional (3D) electrocatalytic particle electrodes to remove complex industrial wastewater.