Study on the joint treatment of acidic mine wastewater by sulfate reducing bacteria and sulfide oxidizing bacteria under different systems

To address the issue of excessive sulfide content in the effluent of acid mine wastewater (AMD) treated by sulfatereducing bacteria (SRB), a series of experiments were carried out. This study combines sulfide oxidizing bacteria (SOB) with SRB to jointly treat AMD. Comparative analysis was conducted on the effectiveness of systems such as sequencing batch symbiosis, microaerophilic symbiosis, anaerobic-microaerophilic series, and pretreatment for treating AMD. The removal efficiency of SO4 2- in AMD by the SRB and SOB series system reached a maximum of 97.65 %. The removal efficiency of Cu2+ and Zn2+ were 97.7 % and 92.86 %, respectively. The maximum yield of S0 reached 71.36 %. Through SEM-EDS, XRD, and XPS characterization methods, it was confirmed that metal ions were removed in the form of metal sulfides, and the remaining sulfides were recovered in the form of elemental sulfur. SRB and SOB have rich microbial community composition in series and symbiotic systems, and the microbial community has good metal tolerance. The series system can not only efficiently remove heavy metal ions and sulfates from AMD, but also effectively recover sulfur from AMD, and the effluent will not cause secondary pollution.