Partial Nitrification Process Of Sewage Treatment Technology Of Ecological Control Of Microorganisms

With the development of molecular biotechnology, it is a great progress in the research of nitrogen pollution prevention and nitrogen biogeochemical cycle. The removal of ammonia nitrogen in the artificial wastewater treatment system is still the concerned by the researchers. Chemoautotrophic ammonia oxidation bacteria are responsible for the removal of ammonia nitrogen, which turns the ammonia nitrogen to the nitrite. This process is the important limiting step in the nitration reaction. Our research uses many molecular biological methods, including Polymerase Chain Reacion, the construction of molecular cloning library, the sequence homology analysis of 16SrDNA, and PLFAs, etc., to do the research of the bacterial diversity of active sludge in Partial Nitrification. With changes of the related wastewater parameters, we can infer operation condition and treatment effect in this process.In different Partia Nitrification process in the microbial community had significant differences, all kinds of microbe groups of content and species are not the same. Through the analysis of phospholipids fatty acids map, the results showed that, bacteria are dominant in this process, and aerobic microorganisms are the dominant bacteria in communities, but the mierobial community system with the different operation conditions changed and the microbial community system in space structure are different. At the same time, regardless of size and proportion of fungi, aerobic bacteria and fungi always exist simultaneously. When air to water ration is relatively small or influent organic concentration is relatively high. SRB and other anaerobic bacteria will appear. These have shown consistent with the mechanism of aerobic nitrification law.In our research. the 16S rDNA gene fragment of bacterium cloning library is by sequence homology analysis. It is estimated that there are at least 26 OTUs after typing by restriction endonuclease cleaving. The bacterial communities are as follows: Proteobacteria. Chlorobi. Nitrospira, Bacteroidetes, Acidobacteria, Candidate division TM7. Chloroflexi, Planctomycetes and Firmicutes. Compared with A/O Process, low DO Process has obvious difference, there are great changes in structure of bacteria communities, but the main community has not changed. The largest fraction was Betaproteobacteria in Partial Nitrification Process. Analysis by cloning a base derived from two different Partial Nitrification process showed a similarity with Chloroflexi. Bacteroidetes and Chlorobi, respectively. Nitrospirae bacterium were also found, which have played important roles in oxidation of ammonia and nitrite in the system. Nitrospirae bacterium accounted for 8.2%in A/O process and little amount in low DO Process. Because of it grows in slow dissolved oxygen in low DO Process and less NOB in this process. So it was presumed that the process of low DO was more suitable to nitrite accumulation and to partial nitrification process. The abundance of Planctomycetes, with the ability of anaerobic oxidation of ammonia, was higher in the process of low DO (9.3%) than that in the process of A/O (2.4%). Therefore, it was presumed that the process of low DO was more suitable to the anaerobic oxidation of ammonia and to perform partial nitrification.Finally, this paper analyes Low DO Partial Nitrification system of ammonium oxidation amoA gene segments of the bacteria. we find out most of the AOB which is sequenced belong to the Nitrosomonas sp. of Betaproteobacteria. The bacteria may exist N. halophilus cluster of Nitrosococcus sp. which belongs to gammaproteobacteria. The sample has high homology with Nitrosopira and Nitrosococcus.Changes of different processing conditions, are directly affected populations in activated sludge. community structure and activity, thus affecting the nitrification process ammonia oxidizing bacteria play a role in the growth, impact on sewage treatment effect. Although we already know the ammonia oxidizing bacteria which play a role in Shortcut Nitrification Process, the results will be the base of the further research in process mechanism in the futuer.