Isolation And Identification Of An Autotrophic Denitrifying Strain With Iron Powder As Electron Donor

Since environmental pollution, the nitrate discharged into the water increases every year, and lead to water eutrophication, water quality deterioration, even water black-odor happened. In our country, most of freshwater systems suffer from eutrophication pollution, and they has become very fragile. Sometimes, the polluted water threatens people's health.Recently nitrogen removal technology has paid people's more and more attention. Wastewater nitrogen removal technology can be divided into phychemical methods and biological methods in general. Physical or chemical methods usually only remove ammonia, as to biological methods can not only removing ammonia, but also can reduce the emissions of total nitrogen in the water. With the development of denitrification technology, it was discovered that some bacteria can complete denitrification using non-organic compounds as an electron donor. Iron is one of the largest elements in the earth's crust as well as it is highly active metals. In this research, we isolated a newly bacteria from anaerobic sludge by the traditional enrichment culture method, which can finish denitrification using iron powder as electron donor. The 16S rDNA sequence compared with the published data in GenBank by using BLAST. The BLAST level of similarity to Pseudomonas sp HPC502 is 99%. This new bacteria belong to Pseudomonas. We tested the nitrogen removal ability of the target bacteria, and found the concentration of phosphate in the medium also reduced. Through further research and experiments, we discussed the mechanism of nitrogen and phosphorus removal by these denitrification bacteria.The study of the denitrification using iron as an electronic was the breakthrough and rich of the traditional denitrification theory. Although some phenomena don't have been explained satisfactory, for the discovery and study of this bacteria, wastewater can be achieved the dual effect of nitrogen and phosphorus removal, which has broad application value and long-term significance. KEY WORDS: denitrification bacteria, autotrophic denitrification, nitrogen removal,...