Abstract:Coal gangue is always used as a soil amendment to improve the poor soil. However, in this study, coal gangue was used as an amendment to phytoremediate the copper mine tailings. Based on the pot experiment, coal gangue was added into the copper mine tailings at the ratio of 0, 1%, 2.5%, 5%, 10% and 15% respectively, and the physical and chemical properties of amended tailings and the growth and physio-ecological characteristics of Vetiveria zizanioides were measured. Results showed that application of coal gangue increased the pH value, organic matter and nutrition elements contents and decreased the available heavy metals contents (Cd, Cu, Pb and Zn) in amended tailings, which improved the poor condition of copper mine tailings. With the increasing addition rates of coal gangue, heavy metals contents in the plant were decreased, biomass and photosynthetic pigments were increased first and then decreased. Meanwhile, soluble protein and proline contents were increased with the increasing addition rates of coal gangue, but MDA contents were decreased. Low addition of coal gangue selectively increased the activities of SOD and CAT, which alleviated the oxidative stress. To sum up, addition of coal gangue into copper mine tailings could stabilize the available heavy metals, and would increase the resistance ability of Vetiveria zizanioides to cope with the harsh environment within a certain addition limit.