Nitrogen removal characteristics and application of bacterium Y5 tolerant to high concentration ammonia nitrogen

Abstract

Nitrogen removal from wastewater is one of the key steps in wastewater treatment. In order to remove high ammonia nitrogen content in water, Shigella boydii Y5, a strain with heterotrophic nitrification and aerobic denitrification performance, was screened from a chemical wastewater, and its optimal survival environment was investigated through single-factor experiments to examine its denitrification performance when applied to real wastewater. The results showed that the optimal environment was sucrose, C/N 10, pH 7, rotational speed 140 r/min, and the strain Y5 grown in this environment had high efficiency of denitrification in wastewater with initial mass concentration of 1 000 mg/L of ammonia nitrogen, and it was a salinophilic bacterium. When strain Y5 was applied to nucleic acid wastewater, the maximum degradation rates of ammonia nitrogen and total nitrogen reached 98.22% and 90.27%, respectively. High-throughput sequencing was used to analyze the stability and role of strain Y5 in the denitrification process of wastewater. The results demonstrated that there was a significant difference in the level of microbial diversity between the treatment group with the addition of carbon source and the treatment group with carbon source and strain Y5, suggesting that Shigella boydii Y5 had great application value for real wastewater treatment.

Keywords

• aerobic denitrification
• shigella boydii
• denitrification performance
• nucleic acid wastewater