Removal of 2,6-dichlorophenol in water by CuO activated peroxymonosulfate: Efficiency, mechanism and degradation pathway

CuO as a heterogeneous catalyst was synthesized by calcination method and characterized via various technologies. A series of metal oxides were synthesized by the same process to compare the catalytic performance. The CuO activated peroxymonosulfate (PMS) catalytic system can effectively degrade 2, 6-dichlorophenol (2,6-DCP). The effect of the calcination temperature on CuO performance was investigated, which showed that the catalytic performance was the highest at a calcination temperature of 400 °C. The effect of various factors such as catalyst dose, PMS dose, solution pH, NOM concentration and inorganic ions (Cl⁻, NO₃⁻, SO₄²⁻ and HCO₃⁻) on the removal of 2, 6-DCP were probed. SO₄^[rad]− and ^[rad]OH play the predominant role for the degradation of 2, 6-DCP. According to the kinetic calculation of the quantitive experiment by nitrobenzene and benzoic acid, the generation concentrations of ^[rad]OH and SO₄^[rad]− can reach 5.92 × 10⁻¹³ mol/L and 7.92 × 10⁻¹³ mol/L, respectively. The degradation mechanism of 2, 6-DCP main including ^[rad]OH substitution for Cl atom, ring-opening and mineralization.