Promotion of Ni2+ Removal by Masking Toxicity toSulfate-Reducing Bacteria: Addition of Citrate

International Journal of Molecular Sciences

Yan Zhou¹  Xiaoyu Zhu²  Xiaohong He²  Junwei Qian²  Yong Tao²  Daping Li² 

[1] College of Life Science, Sichuan University, Chengdu 610064, China;Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences & Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu 610041, China;

关键词: Ni removal;    Ni-citrate complex;    toxicity masking;    lactate;    sulfate reduction;   

DOI  :  10.3390/ijms16047932

来源: DOAJ

【 摘 要 】

The sulfate-reducing bioprocess is a promising technology for the treatment of heavy metal-containing wastewater. This work was conducted to investigate the possibility of promoting heavy metal removal by the addition of citrate to mask Ni2+ toxicity tosulfate-reducing bacteria (SRB) in batch reactors. SRB growth was completely inhibited in Ni2+-containing medium (1 mM) when lactate served as the sole carbon resource, leading to no sulfate reduction and Ni2+ removal. However, after the addition of citrate, SRB grew well, and sulfate was quickly reduced to sulfide. Simultaneously, the Ni-citrate complex was biodegraded to Ni2+ and acetate. The NiS precipitate was then formed, and Ni2+ was completely removed from the solution. It was suggested that the addition of citrate greatly alleviates Ni2+ toxicity to SRB and improves the removal of Ni2+, which was confirmed by quantitative real-time PCR targeting dissimilatory sulfite reductase (dsrAB) genes. Analysis of the carbon metabolism indicated that lactate instead of acetate served as the electron donor for sulfate reduction. This study offers a potential approach to increase the removal of heavy metals from wastewater in the single stage SRB-based bioprocess.

【 授权许可】

Unknown