Removal Of Nitrogen From AS-C By Microoganism

The total nitrogen content of coal is relatively stable, from 1.5% to 2.5%. It is reported that nitrogen content of coal is related to the coal rank and times. The nitrogen is mainly from protein amino acid alkaloid and chlorophyll, which came from plant and microbes. Nitrogen in coal is in the form of nitrogen-containing aromatic compounds, such as pyridine, pyrrole etc. Nitrogen in the form of pyridine is the main component. With the increase of coal rank,pyridine-type nitrogen will transform to pyrrole-type nitrogen, therefore, pyrrole is more abundant in high rank of coal than that in the lower rank of coal. Nitrogen-containing aromatic compounds have strong influence in the quality of coal, which leads directly to the formation of nitrogen oxides(NOx) easily during coal combustion. At present, the research about removal of nitrogen from coal mainly focuses on the catalytic hydrogenation, which goes at high temperature and pressure with longer residence times.Due to the biological process, microorganisms as biocatalysts can metabolize natural organic compounds at ambient temperature and pressure, usually resulting in the energy-saving. Based on the form of nitrogen in coal, we choose pyridine as the model compound and the selection of the microbes was correspondingly confirmed, which can remove nitrogen. In the filter medium, pyridine was used as the sole source of nitrogen. Environment sample of wastewater was inoculated in filter medium to obtain cultures to be capable of using pyridine as sole source of nitrogen.The function between coal and microbes is difficult if microbes are not abundant in water, and the microbe could not react with coal effectively. Coal is unsolvable in water, it is limited in many application fields. Initial results found that alkali-soluble coal (AS-coal) can dissolve in 0.1N NaOH solution, its feature was resemble to the humic coal, and the AS-coal can form solution with water, this feature allows it to react with microbe. In this study, we reported the recent research results about organic nitrogen removal of coal by microorganisms.According to the structure of nitrogen in coal, pyridine is used as the model compound to test the adaptability of the microbe. Add pyridine as the sole nitrogen source for microbe to the screening culture medium, the microbe growing in the medium can use pyridine as the sole nitrogen source. Separate the microbe in growth cultureplat by lineation. Incubate the separated microbe in the medium, which use AS-C as the sole nitrogen source. After 96h, separate AS-C from binded microbe by alkali-washing and acid- precipitation. Analysis the product with element analysis, the result showed that the nitrogen content of the AS-C binded with the microbe was fall from 0.88% to 0.22%. AS-C separated form microbe was 10% of the total AS-C. In the research, microbe uses the nitrogen in AS-C as the nitrogen source, and removal the organic nitrogen from AS-C.