Field Research on Nitrogen Removal Performance of Aerobic Denitrifiers in Source Water Reservoir by Mixing Aeration

Abstract

Changes of total nitrogen (TN), organic matter, microbial metabolic activity, aerobic denitrifying bacteria and aerobic denitrifying genes (nirS and nirK) in water and surface sediments under mixing aeration were studied in Heihe Jinpen Reservoir. Results showed that compared with the control area, the total nitrogen concentration of water and surface sediments in the enhanced area decreased by 29.7%~49.2% and 17.9%. Metabolic activity of microorganisms increased by more than 14%, the utilization rate of carbon source increased by 30% and the McIntosh diversity index of microorganisms increased by 20%. The number of aerobic denitrifiers and genes of aerobic denitrifiers was also increased by 20%. Illumina high-throughput DNA sequencing results showed that the proportion of aerobic denitrifiers such as Acidovorax increased from 0.01% to 0.15%, showing an increase of 15 times. The production practice showed that mixed aeration can improve the metabolic activity and denitrification characteristics of indigenous aerobic denitrifiers, providing theoretical support and technical guarantee for denitrification and carbon removal of slightly polluted source water.