Highly efficient activation of periodate by anodic contact glow discharge electrolysis for 3-chlorophenol degradation in water

Periodate (PI) activation by anodic contact glow discharge electrolysis (ACGDE) was used to degrade 3-chlorophenol (3-CP) in water. The effects of the PI concentration, current intensity (mA), anions (Cl^- and SO₄^2-), organic compounds (humic acid and RhB), and initial solution pH on the 3-CP removal rate were studied. The results show that PI was efficiently activated by ACGDE, leading to the rapid degradation of 3-CP. For the 1.5-mmol/L (mM) PI activated by ACGDE for 1.5 min, the removal rate of 3-CP (100%) was 19 or 6.7 times higher than that of PI or ACGDE alone. The decomposition of 3-CP was affected by the initial pH. Cr⁶⁺ (·H scavenger), 2-propanol (•OH scavenger), and trichloroacetic acid (TCAA, O₂^·- scavenger) were added to study the mechanism of PI activation by ACGDE and the main active species responsible for 3-CP degradation. H• generated by ACGDE is a key active species to activate PI. In addition, ACGDE may be a highly efficient approach for PI activation.