Bacterial-mediated recovery of copper from low-grade copper sulphide using acid-processed rice straw

• Published in: Bioresource technology 2019-09, Vol.288, p.121605-121605, Article 121605
• Main Authors: Yin, Shenghua, Chen, Wei, Chen, Xun, Wang, Leiming
• Format: Article
• Language: English
• Subjects: Acid-processed rice straw; Bacteria community; Bioleaching; Low-grade copper sulphide
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.121605

[Display omitted] •Both bacterial community and copper recovery were explored in presence of acid-processed rice straw.•The addition of acid-processed rice straw improved copper recovery and bacteria growth.•The relationship among better copper recovery, dominant bacteria and acid-processed rice straw were revealed.•Different dosage and state of rice straw were used as promoter during bioleaching. Bacteria community and copper recovery in presence of acid-processed rice straw (ARW) were explored during low-grade copper sulphide bioleaching. The results indicated a strongly promoting response of appropriate-quality ARW with improved bacteria concentration and enhanced copper recovery. The highest bacteria concentration reached 9.54 × 107 cells·mL−1 with an increase by 69.15%. And a maximum of 95.32% copper leaching rate with a relatively low Fe3+ concentration (329.00 mg·L−1) was obtained in presence of 1.0 g powdered ARW compared to only 83.40% in its absence. That is due to less development of passivation layer formed by Fe3+ hydrolysis, which is contributed by reducing ARW. 16S rDNA analysis illustrated the dominant leaching bacteria (Acidithiobacillus ferrooxidans) was influenced significantly, whose proportion reached 40.38% to the total bacteria when the ARW was added compared to 15.92% in its absence. And Stenotrophomonas accounted for the highest proportion of the bacteria community throughout bioleaching process.