Effect Of Magnetic System In SBR Denitrification And The Microbial Comunnity Dynamic Analysis

The nitrogen pollution is the main reason causing water eutrophication, and the removal of nitrogen has become a hot topic in wasterwater treatment as water eutrophication become even worse. As the traditional biological nitrogen removal process has many limitations, it is necessary to research new theory and technology for nitrogen removal. Because of their advantages such as enhancing the treatment effect, reducing the area and reducing the treatment process flow etc, aerobic denitrification process has been widely put attentions. The process was studied in biofilm reactor and simultaneous nitrification and denitrification was studied in SBR.The results show that, in certain intensity of magnetic field, The results showed that the temperature is 20℃~ 30℃range, nitrification efficiency and total nitrogen removal rate increased with increasing temperature. Reactor temperature at 30℃running simultaneous nitrification and aerobic denitrification was the best,in the C / N 6, DO concentration of 1.2mg / L total nitrogen removal rate was 53.7% when, when the DO concentration to 4.0mg / L of total nitrogen removal can be achieved when 45.6 % . With the increase of DO concentration in the reactor on nitrogen removal by the oxygen SND synchronous environment and aerobic denitrifiers dual role gradually evolved into the denitrifying bacteria play a major role.A high efficient aerobic denitrifying bacterium belonging to Pseudomonas sp. was isolated from activated sludge, named T13, having the excellent removal efficiency of nitrate and total nitrogen which achieved 97.7% and 89.7% respectively. The optimal temperature for the growth and denitrification of T13 ranged from 25℃to 35℃, and a nitrogen removal ability of T13 could be found even at a lower temperature such as 15℃. The optimal pH was neutral and low choice, and the optimal C/N was 3-12. Such a strain could utilize nitrate and nitrite as electron acceptors for nitrate respiration, achieving high-efficiency removal of nitrate and nitrite which were higher than 90.3%.The study on DGGE similarity of dactylogram and clustering shows that those magnetic samples are assembling. Magnetic effect boosts up activity of some bacteria species, which adapt magnetic environment. The rest, which is less adaptive, has eliminated. The superior species would be dominating with decending of variety.These kinds of species are more tending to forming steady structure of community.