Study On Comprehensive Effect Of Microbes Combination On Coal Mine Solid Wastes

Pollution control of coal gangue and fly ash has become the primary environmental issue in coal mining area. Improving wastes and accelerating the restoration of vegetation by microbial technology are an important way to improve the ecological environment in mining area. Seeking the potential fertility of wastes and accelerating their transformation to ecological reconstruction by the life activities of the rhizosphere and artificial inoculating microbes are beneficial to the sustainable development of ecosystems. The main objectives and results obtained are listed as follows:(1) The adsorption and desorption properties of phosphorus in the coal gangue and fly ash were studied in the classic banlance method. Results show that the phosphorus adsorption capacity of coal gangue and fly ash increased as added P concentration, however the adsorption rate decreased. The desorption rate increased as increased concentration of the banlance solution. Adsorption propertities of coal gangue, fly ash and mixture of different ratio are better than soil and desorption properties are worse. Irreversible chemical adsorption is the main way.(2) The leaching solution in different process between coal gangue and fly ash has been studied in pole experiments. The results showed that the leaching solution of coal wastes has a quite low pH with serious pollution compared with the requirements of GB3838-2002"Surface Water Quality Standard". Fly ash added can reduce the pollution, such as pH,SO42-,PO43- and Fe. Mixture of coal wastes and fly ash or in different layer can effectively decrease water pollution.(3) Remediation of microbes on different coal waste was studied by inoculating thiobacillus thiooxidans and phosphate-solubilizing bacteria to coal gangue and fly ash separately. Results show as follows: Inoculating thiobacillus thiooxidans to coal gangue significantly removed its sulfurs, produced a lot of H+ and iron, increased EC and PO43- in the leaching solutions. Phosphate-solubilizing bacteria can increase P and EC in leaching solution of fly ash. Thiobacillus thiooxidans has better effect on mixture of coal gangue and fly ash.(4) Effect on the biomass of alfalfa and improvement of coal wastes by mycorrhizal fungi, rhizobium, phosphate-solubilizing bacteria and their combinations were studied through setting different treatments of water and microbial inoculations. Results show as follows: the plant biomass was significantly reduced in water stress. Either single-AM or mixed inoculation significantly increased the biomass of alfalfa and mycorrhizal played a major role. Mixed inoculation improved the biomass of plant better than single-AM. Mycorrhizal fungus infection was not affected in the water stress, but the hyphal density decreased. It can be significantly improved by rhizobium and phosphate- solubilizing bacteria. The availability of phosphorus in wastes was reduced in the water stress. Phosphate-solubilizing bacteria can significantly improve it and ease the negative effects caused by the adsorption of plant.(5) Effect on the biomass of alfalfa and clover and improvement of coal wastes by mycorrhizal fungi, rhizobium, phosphate-solubilizing bacteria and their combinations were studied by setting different treatments of water and inoculations. Results show as follows: Either single-AM or mixed inoculation significantly increased the biomass of alfalfa and clover. Mycorrhizal played a major role. Mixed inoculation improved the biomass better than single-AM. Mycorrhizal fungus infection was not affected by the water stress, but the hyphal density decreased. The hyphal density can be significant improved by rhizobium and phosphate-solubilizing bacteria. The less distance from the root, the lower pH. Phosphate-solubilizing bacteria in different root area can significantly make pH lower.