植物协同微生物诱导碳酸钙沉淀对铜尾矿的固化效果

为探讨微生物诱导碳酸钙沉淀技术(microbially induced calcium carbonate precipitation, MICP)和植物技术对污染矿区的固化效果。利用纺锤型赖氨酸芽孢杆菌(Lysinibacillus fusiformis)、碱蓬(Suaeda salsa)、红砂(Reamuria songarica)开展干旱半干旱高风蚀区尾矿污染固化试验。通过植物根系拉力及根—土复合体抗剪强度表征污染矿区响应效果。结果表明:MICP处理后红砂、碱蓬2种植物根系抗拉力分别增加59.9%,19.7%,抗拉强度分别降低7.4%,22.5%。较MICP处理前,100 kPa下红砂、碱蓬复合体抗剪强度分别提高62.7%,45.9%;200 kPa下分别提高130%,122%;300 kPa下分别提高26.8%,30.6%。胶结后,红砂、碱蓬根系中的半纤维素、纤维素、木质素的含量显著增加(p＜0.05),红砂根系分别增加64%,74%,153%;碱蓬根系分别增加24%,46%,95%。综上,MICP协同植被为干旱半干旱高风蚀尾矿区污染修复提供高效途径,研究结果对实现矿区自然环境改善,加速矿区的生态修复具有重大意义。

Solidification Effect of Calcium Carbonate Precipitation Induced by Plant and Microorganism on Copper Tailings

In order to explore the solidification effect of microbially induced calcium carbonate precipitation (MICP) and plant technology on contaminated mining areas, Lysinibacillus fusiformis, Suaeda salsa and Reamuria songarica were used to carry out the solidification experiment of tailings pollution in arid and semi-arid high wind erosion area. The response effect of contaminated mining area was characterized by plant root tension and root-soil composite shear strength. The results showed that the root tensile strength of R. soongorica and S. salsa increased by 59.9% and 19.7%, and the shear strength decreased by 7.4% and 22.5% after MICP treatment. Compared with before MICP treatment, the shear strength of red sand and S. salsa complex increased by 62.7% and 45.9% at 100 kPa. 200 kPa increased by 130%, 122%; 26.8%, 30.6% at 300 kPa. After cementation, the contents of hemicellulose, cellulose and lignin in the roots of R. soongorica and S. salsa increased significantly (p < 0.05), and the roots of R. soongorica increased by 64%, 74% and 153%, respectively. Suaeda salsa roots increased by 24%, 46%, 95% respectively. In summary, MICP synergistic vegetation provides an efficient and feasible new way for pollution remediation in arid and semi-arid high wind erosion tailings areas. Secondly, the research results can improve the natural environment of the mining area.