Selection and enrichment of aerobic denitrifier in activated sludge system

By adopting sequencing batch reactor, the different effects of selection and enrichment of aerobic denitrifiers in activated sludge system using intermittent aeration mode and continuous aeration mode were investigated. The results showed that the two domestication modes could both raise total nitrogen removal efficiency in aerobic condition. At the condition of aerobic environment(DO ≥ 5 mg/L)and 500 mg/L of TN influent, more than 50% of TN removal rate was achieved. After domesticating activated sludge to enrich aerobic denitrifiers, 105 strains of bacteria were isolated from the sludge and 21 of the 105 strains exhibited high TN removal rates of more than 50%. It was basically certain that these strains were aerobic denitrifiers. Comparing with TN removal efficiencies of the 17 strains of bacteria screened before domesticating sludge, it was further proved that domesticating sludge was beneficial to the enrichment of aerobic denitrifiers.