Abstract: A Co/MCM-41 was prepared by calcination of MCM-41 mesoporous zeolite impregnated with cobalt nitrate to strengthen zero-valent iron/oxygen system for removing organic matters in reverse osmosis concentrate water. The reaction conditions including reaction time and temperature, initial pH of the water, iron dosage and Co/MCM-41 dosage were investigated to examine the removal rate of COD and UV254. The orthogonal experiment results show that the removal rate of COD is up to 54 % under the conditions of 0.5 h, 20 ℃, initial water pH of 5, 5g iron and 3 g Co/MCM-41. The reaction time is the most important factor affecting COD removal. Besides, the removal rate of UV254 reaches 50.7 % under the conditions of 1.5 h, 20 ℃ and initial water pH of 3, 5 g iron and 4 g Co/MCM-41. The initial pH of the water to deal with is proved to be the most important factor affecting UV254 removal. Compared with the results of wastewater treated by iron scraps singly, it can be concluded that the presence of Co/MCM-41 plays an important role in strengthening the ability of zero-valent iron/oxygen system to degrade pollutants in the wastewater.