College of Architecture and Environment, Sichuan University, Chengdu 610065, China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin 644000, China.
College of Architecture and Environment, Sichuan University, Chengdu 610065, China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin 644000, China.
J Hazard Mater. 2022 Oct 5;439:129624. doi: 10.1016/j.jhazmat.2022.129624. Epub 2022 Jul 16.
Tailing disposal technologies such as dry and wet disposal methods have a profound effect on the ecosystem of mining areas. However, the chemical speciation of metal(loid)s and microbial community structure in tailings under different disposal methods are still poorly understood. Here we compared the bioavailable fraction of metal(loid)s and the microbial community in vanadium-titanium (V-Ti) magnetite tailing profiles derived from dry and wet stockpiled methods. In wet tailings, the bioavailability of Cr, Cu, Mn, Ni, V, and Zn was higher than that in dry tailings as identified by BCR sequential extraction. Especially for Cu and Ni, the oxidizable fraction was the predominant fraction except the residual fraction, accounting for 37.2-59.0% and 23.2-36.6% of the total concentration in wet tailings, respectively. Based on 16 S rRNA high-throughput sequencing, totally 12 indicator bacterial taxa were detected in dry tailings against 68 in wet tailings. As the biomarkers in wet tailings, genera Sulfuricurvum, Geobacter, and Pseudomonas were expected to be applied to the transformation of metal(loid)s in the tailings. Our results emphasize the importance of dehydration treatment of tailings before stockpiling to minimize the environmental risks caused by toxic metal(loid)s, and provide insights into the engineering application of microbial technologies in V-Ti magnetite tailing area.
尾渣处置技术，如干法和湿法处置方法，对矿区生态系统有深远影响。然而，不同处置方法下尾渣中金属（类）的化学形态和微生物群落结构仍知之甚少。本研究对比了源自干法和湿法堆存方法的钒钛磁铁矿尾矿剖面上金属（类）的有效态含量和微生物群落。在湿尾矿中，采用 BCR 连续提取法确定 Cr、Cu、Mn、Ni、V 和 Zn 的生物可利用性高于干尾矿。特别是 Cu 和 Ni，可氧化态是除残渣态外的主要形态，分别占湿尾矿总浓度的 37.2-59.0%和 23.2-36.6%。基于 16S rRNA 高通量测序，在干尾矿中检测到 12 个指示细菌类群，而在湿尾矿中检测到 68 个。Sulfuricurvum、Geobacter 和 Pseudomonas 等属被认为是湿尾矿中金属（类）转化的生物标志物，有望应用于尾矿的生物转化。本研究结果强调了在堆存前对尾矿进行脱水处理以最小化有毒金属（类）造成的环境风险的重要性，并为微生物技术在钒钛磁铁矿尾矿区的工程应用提供了思路。
