Enrichment and Screening of Aerobic Denitrifiers from Activated Sludge

By comparing intermittent aeration mode with continuous aeration mode in SBR, the enrichment effect of aerobic denitrifiers in activated sludge system was discussed. The results showed that the two acclimation modes were beneficial to the enrichment of aerobic denitrifiers in the sludge system. After acclimating activated sludge, 105 strains of bacteria were isolated from the sludge and 21 of the 105 strains exhibited high TN removal rates of more than 50%. Eventually, after second screening, 6 strains were confirmed capable of co-respiring by using nitrate and oxygen as electron acceptor and molecular nitrogen was the end product of denitrification. The 6 strains screened were true aerobic denitrifiers. This suggests that as soon as selective pressure is applied in the sludge system, aerobic denitrification of this metabolism is amplified.