矸石添加对铜尾矿中香根草生长及生理生态的影响

为了探索矸石作为改良剂用于尾矿生态修复,通过盆栽试验,将矸石按一定比例(0,1%,2.5%,5%,10%和15%)添加入铜尾砂,基于铜尾砂理化性质变化,探索矸石对尾砂中香根草生理生态的作用特点。结果表明:矸石添加入铜尾砂后,提高了基质pH、有机质和营养元素含量,降低了有效态重金属浓度(Cd、Cu、Pb和Zn),改善了尾矿贫瘠环境。随矸石添加比例增加,香根草体内重金属浓度呈下降趋势,生物量和光合色素含量呈现低促高抑性变化。同时,可溶性蛋白质和脯氨酸含量随矸石添加比例增加而增加,MDA随添加比例增加而降低,低添加比例的矸石选择性提升了SOD和CAT酶活性,增强了香根草清除体内多余活性氧的能力。矸石加入铜尾砂可稳定铜尾矿中有效态重金属,也能在一定添加比例内,提高香根草抵御铜尾矿胁迫环境的能力。

Effects of Coal Gangue Addition on the Growth and Physio-ecological Characteristics of Vetiveria zizanioides Growing in Copper Mine Tailings

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.