Simultaneous nitrification and denitrification in a mixed methanotrophic culture

Abstract

Simultaneous nitrification and denitrification using a mixed methanotrophic culture was investigated. When both NO3 −-N (108 mg l−1) and NH3-N (59 mg l−1) were added into batch reactors, nitrate removal was complete within 10 h at the rate of 47 mg NO3 −-N g VSS−1 day−1 when dissolved oxygen (DO) concentration was maintained at 2 mg DO l−1. Ammonia removal started simultaneously with nitrate removal at a slower rate of 14 NH3-N g VSS−1 day−1. No significant accumulation of nitrite or nitrate during ammonia utilization suggested the occurrence of simultaneous nitrification and denitrification.