Metabolic Effects and Dynamic Migration Characteristics of Adsorbed CH 4 Gas by In-Situ Microorganisms in Mines

The generation and accumulation of CH4 gas has always been a key focus and challenge in the prevention and explosion control of coal mines, posing a serious threat to safe mining. Taking adsorbed CH4 in coal as the research focus, this paper employed microorganisms isolated and extracted from the actual mine environments to systematically analyze the changes of gaseous products after microbial action on coal, as well as the regulatory effects of microorganisms on the adsorption properties of coal. Furthermore, the metabolic mechanisms and dynamic migration behaviors of adsorbed CH4 under microbial action were thoroughly explored. The results showed that the microorganisms promoted the desorption of adsorbed CH4 by altering the pore structure of coal, consumed oxygen in the environment to metabolize both adsorbed and free CH4g as, the generated CO2 gas further promoted the desorption of adsorbed CH4 gas, reduced the CH4 adsorption capacity of coal and changed the adsorption properties of coal. Meanwhile, compared with single methane bacteria, the mixed bacteria, with a smaller inoculation amount, could utilize more carbon sources, consume more oxygen, produce more CO2 gas and CO2 production by microbial units, and simultaneously reduce the saturated CH4 adsorption capacity of coal, enhance the adsorbed CH4 metabolic capacities. These results demonstrated that the mixed bacteria exhibited stronger efficacy than single methane bacteria in occupying adsorption sites, promoting the desorption of adsorbed CH4, metabolizing CH4gas, altering the pore structure of coal, and weakening the adsorption properties of coal. In addition, due to the strong environmental adaptability, the mixed bacteria exhibited more prominent effects on coal samples from their extracted environment. Therefore, for mine CH4prevention and control in coal mines, Chenjiashan Coal Mine is more suitable for inoculation with mixed bacteria of C/T-T7, while Xiashijie Coal Mine is suitable for inoculation with mixed bacteria of X/T-S2. The research results have important guiding significance for the explosion prevention and suppression of combustible gases in mines and ecological environmental protection.