Enhancing column bioleaching of chalcocite by isolated iron metabolism partners Leptospirillum ferriphilum/Acidiphilium sp. coupling with systematically utilizing cellulosic waste

Abstract

The iron metabolism partners Leptospirillum ferriphilum and Acidiphilium sp. were screened from industrial bioheap site. An integrated multi-stage strategy was proposed to improve chalcolite column bioleaching coupling with synergistical utilization of cellulosic waste such as acid hydrolysate of aquatic plants. L. ferriphilum was used to accelerate the initial iron metabolism, and Acidithiobacillus caldus maintained a lower pH in the middle stage, while Acidiphilium sp. greatly inhibited jarosite passivation in the later stage. Meanwhile, L. ferriphilum (38.3 %) and Acidiphilium sp. (37.0 %) dominated the middle stage, while the abundance of Acidiphilium sp. reached 63.5 % in the later stage. The ferrous, sulfate ion and biomass were improved and the transcriptional levels of some biofilm and morphology related genes were significantly up-regulated. The final Cu2+ concentration reached 325.5 mg·L-1, improved by 43.8 %. Moreover, Canonical Correlation Analysis (CCA) analysis between bioleaching performance, iron/sulfur metabolism and community verified the important role of iron metabolism partners.