Simultaneously enhance iron/sulfur metabolism in column bioleaching of chalcocite by pyrite and sulfur oxidizers based on joint utilization of waste resource.
Simultaneously enhance iron/sulfur metabolism in column bioleaching of chalcocite by pyrite and sulfur oxidizers based on joint utilization of waste resource.
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DOI：
10.1016/j.envres.2020.110702
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发表时间：
2021-01
影响因子：
8.3
通讯作者：
S. Feng;Yijun Yin;Zongwei Yin;Hailing Zhang;Deqiang Zhu;Y. Tong;Hailin Yang
中科院分区：
文献类型：
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作者：
S. Feng;Yijun Yin;Zongwei Yin;Hailing Zhang;Deqiang Zhu;Y. Tong;Hailin Yang
辉铜矿（Cu 2S）细菌浸出过程中，铁代谢不足是制约浸出的关键因素。黄铁矿（FeS 2）是辉铜矿细菌浸出过程中最常见的硫化矿物，能释放Fe（Ⅱ），弥补辉铜矿细菌浸出过程中铁代谢的不足。在模拟工业系统中，基于废弃物资源的联合利用，采用黄铁矿和硫氧化剂同时强化铁硫代谢，改善辉铜矿的生物浸出效果，并对浸出液中的细菌群落结构和浸出性能进行了系统研究。由于硫/铁代谢活跃，pH值达到1.2，Fe 3+增加了77.78%，而反硝化细胞的生物量提高到2.19 × 107 cells/mL。红外光谱和X射线衍射分析结果表明，铁硫代谢活跃，铁硫晶体生成增多。扫描电子显微镜（SEM）观察发现，矿石表面出现大量的衍生物颗粒和腐蚀痕迹，表明矿物-微生物相互作用增强。共聚焦激光扫描显微镜（CLSM）显示细胞和胞外聚合物（EPS）在矿石表面的积累，表明更强的接触浸出机制。群落结构和典范对应分析（CCA）表明，硫氧化细菌和黄铁矿的引入可以维持较高水平的优势浸出微生物多样性，硫杆菌（27.75%）和钩端螺旋菌（20.26%）是浸出过程中的优势硫氧化细菌和铁氧化细菌。在多重正效应的累积下，铜离子浸出率提高了44.8%。总之，这种新型的多重干预策略可以为低品位矿石的生物浸出提供重要的指导。
In chalcocite (Cu2S) bioleaching, the lack of iron metabolism is a key restricting factor. As the most common sulfide mineral, pyrite (FeS2) can release Fe(Ⅱ) and compensate for the iron metabolism deficiency in chalcocite bioleaching. The bioleaching of chalcocite in an imitated industrial system was improved by enhancing the iron–sulfur metabolism simultaneously using pyrite and sulfur oxidizers based on the joint utilization of waste resources, while the bioleaching performance and community structure in the leachate were systematically investigated. Due to the active sulfur/iron metabolism, the pH reached 1.2, and Fe3+was increased by 77.78%, while the biomass of planktonic cells was improved to 2.19 × 107cells/mL. Fourier transform infrared reflection (FTIR) and X-ray diffraction (XRD) analysis results showed that more iron–sulfur crystals were produced due to more active iron–sulfur metabolism. Scanning electron microscopy (SEM) revealed that many derivative particles and corrosion marks appeared on the surface of the ore, implying that the mineral–microbe interaction was strengthened. Confocal laser scanning microscopy (CLSM) showed the accumulation of cells and extracellular polymeric substances (EPS) on the ore surface, indicating a stronger contact leaching mechanism. Furthermore, the community structure and canonical correspondence analysis (CCA) demonstrated that the introduction of sulfur-oxidizing bacteria and pyrite could maintain the diversity of dominant leaching microorganisms at a high level.Sulfobacillus(27.75%) andLeptospirllillum(20.26%) were the dominant sulfur-oxidizing and iron-oxidizing bacteria during the bioleaching process. With the accumulation of multiple positive effects, the copper ion leaching rate was improved by 44.8%. In general, this new type of multiple intervention strategy can provide an important guide for the bioleaching of low-grade ores.