蓝藻结皮在离子型稀土尾矿生物修复中的应用前景

Insights for Applicability of Cyanobacterial Crusts in Ionic Rare-earth Tailings Bioremediation

赣南地区采用池浸、堆浸、原地浸矿三种工艺提取离子型稀土元素,造成矿区及周围原有的表层结构破坏,出现土壤沙化、酸化加重、粗颗粒比重大以及镉(Cd)、铜(Cu)、砷(As)含量超过土壤背景值等系列环境问题。天然土层受损,立地条件变差,通过接种耐受型微生物形成结皮来改良土壤是一种较好的土壤污染治理方法。蓝藻(Cyanobacteria)是分布广泛且对极端不良环境具有极大的适应性的初级生产者。研究发现蓝藻土壤接种能促进土壤溶解性有机质含量增多、土壤养分再分配、稳定表层砂土,抗逆性强、修复速度快、效果明显,蓝藻结皮改良土壤的研究已成功应用于沙漠治理与生态修复,但在稀土尾矿的治理研究极少。通过土壤及矿区环境中蓝藻特征及其种间关系、分布等方面综述分析得出,接种蓝藻形成的藻结皮能有效地改良废弃稀土尾砂,具有较好的应用前景。

The leaching technology of ion adsorption rare earth ore in Gannan including heap leaching, pool leaching and in-situ leaching has caused destruction of intrinsic surface structure in mines and surrounding areas, the main issues include sandy desertification, acidity increased, high content of coarse sand and content of Cd, Cu, As higher than that of Chinese soil. Considering the damaged topsoil and poor site conditions, the soil can be improved effectively by inoculating resistant microbeand to form crusts. Cyanobacteria are prevalent primary producers and have strong adaptability to extremely adverse environmental conditions. The relative researches indicate some advantages such as cyanobacteria inoculation can promote soil dissolved organic and soil nutrients redistribution and surface tailings stabilization, and charactered by strong resistance, less-time restoration, obvious effects.And yet cyanobacteria inoculation succeeded in combating desertification and ecological restoration, and is rarely used in rare-earth tailings. This review described the characteristics of cyanobacteria and their accompanying relationships with other organisms in the soil and mines, as well as cyanobacteria distribution. Cyanobacterial crusts formed by inoculated cyanobacteria can improve effectively abandoned rare-earth tailings, which has good application prospects.