Screening of a Salt-Tolerant Heterotrophic Nitrification-Aerobic Denitrification Strain and Optimization of Its Nitrogen Removal Conditions

Abstract

To reduce ammonia nitrogen-induced environmental hazards, strain N1-1 was screened from coal-to-liquid wastewater and identified as Halomonas. Its optimal denitrification conditions were confirmed via single-factor experiments. Subsequently, through continuous optimization of the culture medium components, the optimal degradation conditions for the strain were obtained: 3% salt concentration, a culture temperature of 32 °C, pH 8.0, and an agitation speed of 200 rpm. Furthermore, performance tests conducted under these optimized conditions showed that when the initial ammonia nitrogen concentration was 300 mg/L, the strain exhibited significant removal capacity within 24 hours, achieving an ammonia nitrogen removal rate of over 80%. With strong salt tolerance and adaptability, this strain has great application prospects in high-salt ammonia wastewater treatment.