Simultaneous recovery of valuable metal ions and tailings toxicity reduction using a mixed culture bioleaching process. (20th September 2021)

• Record Type: Journal Article
• Authors: Liao, Xiaojian; Ye, Maoyou; Li, Shoupeng; Liang, Jialin; Zhou, Siyu; Fang, Xiaodi; Gan, Qiaowei; Sun, Shuiyu
• Is Part Of: Journal of cleaner production. Volume 316(2021)
• Publication Date: 2021-09-20
• Subjects: Lead–zinc sulfide mine tailings -- Bioleaching -- Bacterial combination -- Extracellular polymeric substances -- Environmental risk; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2021.128319
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Lead–zinc sulfide mine tailings without appropriate disposal would cause resource waste and heavy metal pollution in the environment. This study aims to design a novel mixed culture A with higher leaching performance to improve the leaching efficiency of tailings, because mixed culture B consisting of ferrous oxidizer Leptospirillum ferriphilum ( L. ferriphilum ) and sulfur oxidizer Acidithiobacillus thiooxidans still has a long leaching period. The results showed that mixed culture A containing ferrous/sulfur oxidizers Acidithiobacillus ferrooxidans and Sulfobacillus thermosulfidooxidans shortened the bioleaching cycle by 30% to achieve the same zinc yield (94.0%) as mixed culture B. Thus, ferrous/sulfur oxidizers offer a competitive advantage over ferrous oxidizer and sulfur oxidizer, respectively, during bacterial combination to leach tailings. The better performance of mixed culture A was verified by its higher content of extracellular polymeric substances and living cells density (30.2 × 10 7 cells mL −1 ). Furthermore, data from microbial community succession also revealed that two bacteria could together produce acid in the mixed culture A system to substantially facilitate zinc leaching, while only L. ferriphilum played a role in mixed culture B system. Interestingly, results from toxicity evaluation of bioleached residues indicated that mixed culture A dramatically reduced the potential ecological risk index of tailings from 161.80 to 7.50, transforming tailings from hazardous waste into non-hazardous one. In brief, this study proposes a novel perspective for bacterial combinations to improve tailings bioleaching and reveals that bioleaching can reduce the eco-environmental risk of tailings. Graphical abstract: Image 1 Highlights: Ferrous/sulfur oxidizers should be preferred for bacterial combination. Designed mixed culture A significantly reduces the bioleaching period. The leaching performance of mixed cultures was characterized via EPS analysis. Bioleaching can reduce the eco-environmental risk of tailings.