Changes in microbial community structure during the biooxidation of iron and inorganic/organic sulfur provide prediction of acid mine drainage from coal spoil

To thoroughly investigate the formation mechanism of acid mine drainage (AMD) from coal mine spoil, this study con-ducted microbial shake flask experiments on gangue possessing inorganic and organic sulfur to predict the future gen-eration of AMD. The results revealed that microbial-mediated sulfur oxidation effectively lowered the pH of leachate and increased metal ion and sulfate concentrations. The oxidation of pyrite sulfur and thiophene sulfur contributed to 70 % and 30 % of the total acid production, respectively, highlighting the importance of both processes in coal mine acidification. The abundance and diversity of the microbial community increased, with new iron and sulfur oxidiz-ing bacterial species during acidification, with new iron and sulfur oxidizing bacterial species, such as Sulfobacillus sp. and Acidibacillus sp., emerging and constituting approximately one-third of the bacterial population. These bacteria survived desiccation and proliferated faster than A. ferrooxidans YQ-N3 when conditions favored growth.

Automated summary

To investigate the formation mechanism of acid mine drainage (AMD) from coal mine spoil, microbial shake flask experiments were conducted, revealing that microbial-mediated sulfur oxidation plays a crucial role in coal mine acidification. The oxidation of pyrite sulfur and thiophene sulfur contribute significantly to acid production, with the emergence of new iron and sulfur oxidizing bacterial species. These bacteria showed higher resilience and faster proliferation compared to A. ferrooxidans YQ-N3 when favorable conditions were present.