Research progress of in situ control technology for acidification pollution of coal gangue pile based on chemical-microbial method

Sulfur-containing gangue in the open storage process will produce acidification pollution, releasing a large amount of toxic and harmful gases and high saline acidity wastewater.Commonly used physical barrier measures are difficult to meet the demand of small volume of works and convenient to take away gangue during short-term storage of coal gangue.Therefore, finding a temporary suppression measure of coal gangue acidification based on chemical and microbial methods is a hot issue in the field of ecological restoration in mining areas.In view of the characteristics of the gangue oxidation process regulated by microorganisms, the current situation and problems of the application of chemical and microbial methods in the in situ control of coal gangue pile pollution are summarized.The chemical method inhibits the activity of oxidizing bacteria by applying organic bactericides to reduce the rate of gangue oxidation, but a large number of applied bactericides may bring environmental risks; the microbial method removes salt and heavy metal ions by screening and domesticating reducing bacteria and adjusting the pH value of drench solution, but it needs to rely on the external carbon source.On this basis, a chemical-microbial synergistic in situ control technology for acidification pollution of coal gangue pile is proposed, using organic bactericides to provide carbon sources for reducing bacteria, and reducing bacteria to degrade bactericides can reduce environmental risks.In addition, the improvement of bacterial strains and the development of new biocides and their corrosion inhibitors will be the key direction of future research.