Nitrogen Removal Characteristics Of Cold-Resistant Heterotrophic Nitrification And Aerobic Denitrification Bacterium

Taking the typical landscape water bodies located in the main urban area of Shijiazhuang city as examples,the heterotrophic nitrification-aerobic denitrification bacterium with cold tolerance were isolated from the sediments through specific enrichment and acclimation method at 10?.Moreover,the strain was identified by 16 S rRNA,and physiological and biochemical characteristics,respectively.Then,this paper explored the optimal growth conditions of high-efficiency strains based on single factor experiments as well,investigated the nitrogen metabolism of strains under different nitrogen concentrations,and applied different biological fillers to study the denitrification performance of highefficiency strains.It provided reference for the practical application of heterotrophic nitrification aerobic denitrification bacteria.The main results were as follows:1)Pseudomonas canadensis SY21 and Pseudomonas extremaustralis SY76 were highly effective cold-tolerant heterotrophic nitrification-aerobic denitrification bacteria obtained from the landscape water sediments.And the bacteria were gram-negative,SY21 was dibacillus,SY76 was short bacillus.2)The optimal C/N was 12,the optimal inoculation quantity(v/v)was 2%,and the optimal pH was 7~8.Subsequently,strain SY21 was selected for the experiment.3)When ammonia and nitrate as the sole nitrogen sources,respectively,the nitrogen removal rate of strain SY21 were above 70%.When nitrite as the sole nitrogen source,the nitrogen removal rate was about 60%.And when ammonia and nitrate as the mixed nitrogen sources,the removal rate of ammonia and nitrate were 85~90% and 35~40%,respectively.4)The strain SY21 in the experiment of Babilun packing showed the strongest adaptability,and the nitrogen removal rate reached 84.12%.