Screening Of Nitrogen Removal Microorganism And Study Of Its Characteristics

Cyanobacteria of eutrophic water release nitrogen pollution during dying and degradation, which cause high nitrogen contents. Getting the cyanobacteria out of water by salvage, reduce the nitrogen level of water. While, domestic research on salvage trement of cyanobacteria resource, have done a lot of research on methane production by anaerobic fermentation. In the process of biogas production, reducing the nitrogen gas in the proportion amd increasing the methane in the proportion had been research focus. Research on efficient removal of microorganisms, can be applied not only to control environmental pollution, but also to reduce the proportion of nitrogen in the methane fermentation. The purpose of this study was to screen with ammonification, nitrification and denitrification microorganisms, stuying the characteristics of the micro-organisms, algae removal and applied research, to provide a scientific basis to achieve energy using and reference.In this paper, we screen and isolate ammonification bacteria, nitrification bacteria and denitrification bacteria from the lake sediment of Chaohu Lake. Taken by the primary screening and re-screening, we choose efficient strains of ammonification bacteria, nitrification bacteria and denitrification bacteria,which were strain A5, strain X5, strain F3 and F6. Strain A5 and X5 were identified Gram-negative and Gram-positive. By biochemical identification and identification of 16S rDNA experiment, the strain X5 was identified as Bacillus sp., and has a 100%.similarity to the 16S rDNA sequence of Bacillus subtlis.By determining biomass and dynamics study, and the study of initial pH value, temperature, inoculum size and other single factor analysis, the results of strain A5 and X5 experimental are as follows:(1) after 24h in culture strain A5 maximum biomass, and after 36h, the ammonia generation rate was achieve optimum. A5 Optimal ammonia nitrogen production capacity of strain A5 was observed under conditions of 35℃,36 h, pH7.0-8.0 and 4% inoculum. (2) after 36h in culture strain A5 maximum biomass, the ammonia generation rate was achieve optimum. Optimal ammonia nitrogen production capacity of strain X5 was the best carbon source for the D-fructose, the best nitrogen source was ammonium oxalate,and capacity of strain X5 was observed under conditions of 25℃-35℃,16 h, pH7.0-8.0 and 6% inoculum.In this test, added the screening strains of A5, X5, F3 and F6 into cyanobacteria fermentation device, in order to carry out the algae removal treatment. The results showed that nitrogen removal through microbial treatment, the nitrogen content of cyanobacteria indeed decline; gas chromatographic N2 content increased, up to 92.23%.