不同比例黄铁矿对嗜酸微生物-辉锑矿相互作用的影响研究

Study on the effect of different proportions of pyrite on the interaction between acidophilic microorganisms and stibnite

针对辉锑矿(Sb_2S_3)的嗜酸微生物溶解过程,研究不同比例黄铁矿(FeS_2)对嗜酸微生物-辉锑矿相互作用的影响。结果表明,微生物群落门水平丰度最高的为变形菌门(Proteobacteria),是主要的锑耐受菌;属水平丰度最高的为嗜酸硫杆菌属(Acidithiobacillus),是酸性矿山环境的代表性优势属。SEM-EDS结果表明,微生物作用体系中,Sb_2S_3∶FeS_2为1∶1和1∶2时,矿物残渣表面发现较多腐蚀坑及细微颗粒,且Sb_2S_3∶FeS_2为1∶1时矿物界面反应更强。XRD和XPS结果表明,FeS_2促进了嗜酸微生物对Sb_2S_3的氧化分解及硫的氧化。Tafel极化曲线和交流阻抗结果表明,Sb_2S_3∶FeS_2为1∶1时微生物作用体系腐蚀电流密度最大,电荷转移阻抗最小。结果对理解锑矿区锑的迁移转化和环境归趋,进一步促进锑污染治理技术的发展具有重要意义。

This study focused on the acidophilic microbial dissolution process of stibnite and investigated the effect of different pro-portions of pyrite on the interaction between acidophilic microorganisms and stibnite.The results showed that the Proteobacteria had the highest abundance at the phylum level,it was the main stibnite-tolerant bacterium.Acidithiobacillus had the highest level of abundance at the genus level,which was the representative dominant genus in acid mine environments.Additionally,SEM-EDS results showed that for microbial action systems with Sb2S3∶FeS21∶1 and 1∶2,more corrosion pits and fine particles were found on the surface of mineral residues,and for the microbial action system with Sb2S3∶FeS21∶1,the interfacial reaction between stibnite and pyrite was stronger.XRD and XPS results indicated that the addition of pyrite could promote the oxidative decomposition of stibnite and sulfur oxi-dation by acidophilic microorganisms.Tafel polarization curves and EIS impedance results showed that when Sb2S3∶FeS2 was 1∶1,the microbial system had the highest corrosion current density and the smallest charge-transfer impedance.The above results were of great significance for understanding the migration,transformation,and environmental fate of stibnite in antimony mining areas,and further pro-moting the development of antimony pollution control technologies.