Studies On Lignite Degradation By White Rot Fungi

China has abundant coal resources, with low-level resources of lignite and weathering coal in particular. If lignite is burned directly, its thermal efficiency and value of industrial application is low.When piled up open-air for a long term, lignite not only causes a waste of energy,but also leads to environmental pollution easily.The biodegradation of lignite is a new cross subject,and is also a prospective fundamental research in the field of Bio-mining technology.The paper selects white rot fungi as the bioconversion bacteria of Yi-Ma lignite which has the ability to degrade lignin.It also studies the culturing conditions and growth features of white rot fungi.The influence of the size of coal , quantity of bacterium , concentration of coal slurry and time of degradation is studied in the experiments of lignite biodegradation.The results of experiments indicate that the size of coal has a great effect on lignite biodegradation,and the the quantity of bacterium,the concentration of coal slurry and the time of degradation has some effect. In the selected experiment conditions,the optimum level of every factor is: the size of coalï¹£0.2 mm; the quantity of bacterium 10 mL;the concentration of coal slurry 0.9g/50 mL;the time of degradation 12d.In order to improve the efficiency of lignite degradation,we mutagenesis white rot fungi by means of ultraviolet ray in the research.The results show that White rot fungi is sensitive to ultraviolet ray.The lethality rate of spores of white rot fungi by ultraviolet ray reach 89.50 percent with radiation time 160s. And the efficiency of coal degradation is the best when the death rate is 58.80 percent radiated with 40s,with the degradation rate 37.6 percent of Yi-ma lignite and 51.62 percent of lignite pretreated with nitric acid.Methods of XRD,FTIRand element analysis are used to analyse the products of lignite degradation.The results indicate that the degree of polymerigation of aronatic nucleus decreased as well as the molecular weights after lignite was biodegraded by white rot fungi.At the same time ,we analyse the lignite dagradation mechanism preliminarily.We conclude that it is an oxidation and hydrogenation process to degrade lignite by white rot fungi,containing both organic matters and macromolecule organic polymers.