CuMgFe layered double oxide (CuMgFe-LDO) was successfully obtained from CuMgFe layered double hydroxide (CuMgFe-LDH) and employed to degrade phenol in the heterogeneous catalysis of persulfate (PS). The effects of CuMgFe-LDO dosage, PS concentration, initial pH (pH(0)) and the presence of common inorganic anions on the removal of phenol were comprehensively evaluated in this study. It was revealed that CuMgFe-LDO performed excellently in activating PS to remove phenol with a great stability under a wide range of pH(0) values ranging from 5.0 to 11.0. With 0.5 g/L CuMgFe-LDO and 0.5 mmol/L PS at pH(0) 6.4, 95.3% of 0.1 mmol/L phenol was removed within 30 min. Based on the results of electron paramagnetic resonance (EPR) and radical quenching experiments, it was inferred that free radicals bounded to the surface of CuMgFe-LDO was the dominant oxidant for the degradation of phenol. Furthermore, p-benzoquinone was considered to be the major intermediate in the oxidation process. Finally, the CuMgFe-LDO exhibited excellent stability after 3 times recycling with the concentration of the leached copper ion at 0.19 mg/L, being lower than the drinking water standard of U.S Environmental Protection Agency (1.3 mg/L). The findings of the work provided a new insight into the remediation of phenol polluted water within the system of CuMgFe-LDO/PS. (C) 2017 Elsevier B.V. All rights reserved.