Study on the effectiveness of sulfate-reducing bacteria to remove Pb(II) and Zn(II) in tailings and acid mine drainage

Yanrong Dong; Ziqing Gao; Junzhen Di; Dong Wang; Zhenhua Yang; Xuying Guo; Xiaotong Zhu

doi:10.3389/fmicb.2024.1352430

Study on the effectiveness of sulfate-reducing bacteria to remove Pb(II) and Zn(II) in tailings and acid mine drainage

Front Microbiol. 2024 Mar 28:15:1352430. doi: 10.3389/fmicb.2024.1352430. eCollection 2024.

Authors

Yanrong Dong^{1

2}, Ziqing Gao¹, Junzhen Di¹, Dong Wang², Zhenhua Yang², Xuying Guo³, Xiaotong Zhu¹

Affiliations

¹ College of Civil Engineering, Liaoning Technical University, Fuxin, China.
² School of Mining, Liaoning Technical University, Fuxin, China.
³ College of Science, Liaoning Technical University, Fuxin, China.

Abstract

In view of water and soil getting polluted by Pb(II), Zn(II), and other heavy metals in tailings and acid mine drainage (AMD), we explored the removal effect of sulfate-reducing bacteria (SRB) on Pb(II), Zn(II), and other pollutants in solution and tailings based on the microbial treatment technology. We used the scanning electron microscope-energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and X-ray fluorescence (XRF), to reveal the mechanism of SRB treatment of tailings. The results showed that SRB had a strong removal capacity for Zn(II) at 0-40 mg/L; however, Zn(II) at 60-100 mg/L inhibited the growth of SRB. Similarly, SRB exhibited a very strong ability to remove Pb(II) from the solution. At a Pb(II) concentration of 10-50 mg/L, its removal percentage by SRB was 100%. SRB treatment could effectively immobilize the pollutants leached from the tailings. With an increase in the amount of tailings added to each layer, the ability of SRB to treat the pollutants diminished. When 1 cm of tailingssand was added to each layer, SRB had the best effect on tailing sand treatment. After treatment, the immobilization rates of ${SO}_{4}^{2 -}$ , Fe(III), Mn(II), Pb(II), Zn(II), Cu(II), and total Cr in the leachate of #1 tailing sand were 95.44%, 100%, 90.88%, 100%, 96.20%, 86.23%, and 93.34%, respectively. After the tailings were treated by SRB, although the tailings solidified into a cohesive mass from loose granular particles, their mechanical strength was <0.2 MPa. Desulfovibrio and Desulfohalotomaculum played the predominant roles in treating tailings by mixing SRB. The S^2- and carbonate produced by mixing SRB during the treatment of tailings could metabolize sulfate by combining with the heavy metal ions released by the tailings to form FeS, MnS, ZnS, CuS, PbS, Cr₂S₃, CaCO₃, MnCO₃, and other precipitated particles. These particles were attached to the surface of the tailings, reducing the environmental pollution of the tailings in the water and soil around the mining area.

Keywords: acid mine; heavy metals; sulfate-reducing bacteria (SRB); tailing sands; treatment.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This research was supported by the National Natural Science Foundation of China (52304188), Liaoning Provincial Natural Science Foundation Project (Doctoral Research Start-up Program) (2023-BS-201), and Liaoning Provincial Department of Education Basic Research Project (Youth Project) (LJKQZ20222319). Science and technology research funded by Liaoning Provincial Education Department (LJKFZ20220199), the Discipline Innovation Team of Liaoning Technical University (LNTU20TD-01, LNTU20TD-21), and Key Projects of Liaoning Provincial Department of Education (LJKZ0324).