Effect of Bactericides on Control of Acidification Pollution and Spontaneous Combustion of Coal Gangue Dumps in China and Its Mechanism

Oxidation of pyrite in the coal gangue dumps usually results in acidification and spontaneous combustion, causing many environmental problems such as air, soil, and water pollution. The oxidizing bacteria exacerbate problems such as acidification, spontaneous combustion, and explosions. The bacteriumAcidithiobacillus ferrooxidanswas first separated and isolated from coal gangue samples. Bactericides such as Triclosan, Kathon (isothiazolinones), and sodium dodecyl sulfate (SDS) were selected for our study. Our findings indicated that the addition of bactericide effectively inhibited the oxidation of Fe2+, preventing pH decreases and oxidation-reduction potential increases. We also investigated the bactericidal mechanisms employed by the three bactericides againstA. ferrooxidansby conducting a protein flocculation test, scanning electron microscopy, and time-of-flight mass spectrometry. We found that the specific inhibitory activities of the three bactericides differed. Kathon treatment causedA. ferrooxidansto release small amounts of proteins and lipids.A. ferrooxidanstreated with Triclosan released small amounts of lipids and large amounts of plasmas. SDS caused the bacteria to release a large amount of proteins and lipids and degraded the surface structure of the cells, resulting in altered cell morphology.