Achieving Short-Cut Nitrification Using FA Inhibition and Real-Time Control Strategy in a Combined System Removing Nitrogen from Real Mature Landfill Leachate
A combined system consisting of a up-flow anaerobic sludge blanket (UASB), an anoxic/aerobic (A/O)reactor and a sequencing batch reactor (SBR), was introduced to treat a mature landfill leach ate with a high ammonia concentration and low ratio of COD/TN. After 110 days of stable operation, the results indicated that denitrification and methanogenesis took place simultaneously in the UASB and then the denitrification of nitrite and nitrate in the returned sludge by using the residual COD was accomplished in the A/Oreactor. The residual ammonia was removed in SBR as well as nitrite and nitrate produced by nitrification. when the total nitrogen (TN) concentration of influent leach ate was about2080 mg/L and the ammonia nitrogen concentration was about1970 mg/L, Nitrification and nitrogen removal were usually both higher than 99% and the TN and ammonia nitrogen concentrations of final effulent were about 12 mg/L and 6 mg/L, respectively. The shortcut biological nitrogen removal was achieved stably both in A/O reactor with FA control and in SBR with real-time control strategy with 94% and 93% nitrite accumulation, respectively, and microbial analysis data strongly supported that AOB and NOB competition could be manipulated through long-term application of both real-time control strategy and FA control strategy.