Abstract:
Tailing sand contains a large number of heavy metals and sulfides that are prone to forming acid mine drainage (AMD), which pollutes the surrounding surface environment and groundwater resources and damages the ecological environment. Microbially induced calcium carbonate precipitation (MICP) technology can biocement heavy metals and sulfides in tailing sand and prevent pollution via source control. In this study, through an unconfined compressive strength test, permeability test, and toxic leaching test (TCLP), the curing effect of MICP was investigated in the laboratory and the effect of grouting rounds on curing was also analyzed. In addition, the curing mechanism of MICP was studied by means of Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction spectroscopy (XRD), and scanning electron microscopy (SEM). The experimental results showed that MICP could induce calcium carbonate precipitation through relatively complex biochemical and physicochemical reactions to achieve the immobilization of heavy metals and sulfides and significantly reduce the impact of tailing sand on the surrounding environment.
摘要:
尾矿砂含有大量易形成酸性矿井排水(AMD)的重金属和硫化物,污染了周围的地表环境和地下水资源,破坏了生态环境。微生物诱导碳酸钙沉淀(MICP)技术可以生物清除尾砂中的重金属和硫化物,并通过源头控制防止污染。在这项研究中,通过无侧限抗压强度测试,渗透性试验,和有毒浸出试验(TCLP),在实验室研究了MICP的固化效果,并分析了灌浆轮对固化的影响。此外,利用傅里叶变换红外光谱(FTIR)研究了MICP的固化机理,热重分析(TGA),X射线衍射光谱(XRD),和扫描电子显微镜(SEM)。实验结果表明,MICP可以通过相对复杂的生化和物化反应诱导碳酸钙沉淀,实现重金属和硫化物的固定化,显著降低尾砂对周围环境的影响。