shows the changes in NH4-N removal with time. Salt accumulation at the beginning of the operation resulted in mild
deterioration of nitrifying activity in the bioreactor, which caused NH4-N to accumulate to around 10.0 mg/L in the first 15 days. This is expected since ammonia oxidizing bacteria (AOB) are generally slow growing and sensitive to changes in environmental conditions (such as temperature and salinity) (Lay et al., 2010), and the activities of the AOB are easily inhibited by elevation of salinity which hampers the biological conversion of NH4-N