EFFECT OF SUBSTRATE CONCENTRATION ON THE OPERATION PERFORMANCE OF ANAMMOX PROCESS IN A UASB REACTOR

Abstract

 The effects of substrate concentration on the operation performance of Anammox process in a UASB reactor were investigated by a continuous experiment operated at 33ºC. The influent concentration of total nitrogen (TN) was changed periodically to study the performance at each condition. The removal efficiency, Anammox activity and inhibitory factors were also investigated along with the height of the reactor. As a result, at nitrogen loading rate (NLR) of 5.6 kgN/m³/d, the average TN removal ratio reached 83.3% when the influent TN concentration was maintained below 450 mg/L. The sludges sampled from the bottom part of the reactor showed higher specific Anammox activities (SAA) compared to those obtained from the middle and upper parts of the reactor. It was also revealed that when influent TN concentrations were above 550 mg/L, free ammonia and free nitrous acid inhibited the SAA of the sludge at the bottom part of the reactor, resulted in decrease of TN removal efficiency.