Enhancement of nitrogen removal in moving bed sequencing batch reactor with intermittent aeration during REACT period

This study was conducted to evaluate the performance of moving bed sequencing batch reactor integrated with intermittent aeration strategy (IA-MBSBR) in nitrogen removal from low COD/N wastewater. The IA-MBSBR with a packing volume of 8% (v/v) of 8-mL polyurethane (PU) foam cubes was capable of achieving a total nitrogen (TN) removal of 57% primarily via simultaneous nitrification and denitrification (SND) process. From the batch experiments, the stored carbon substrate in the biomass located inside the acclimated PU foam cubes was found to be responsible for facilitating the denitrification process. The suspended-growth biomass was found to play the major role in the process of oxidizing the ammonium nitrogen (NH4+–N) to oxidized nitrogen (NO2-–N and NO3-–N). Among the batch reactors operated with the same IA strategy and packed with 20%, 30% and 40% (v/v) of 8-mL acclimated PU foam cubes, complete TN removal was achieved in the reactor with 30% of support media concentration.

► Evaluation of nitrogen removal in IA-MBSBR treating low COD/N wastewater.
► Determination of stored carbon substrate which facilitates SND process.
► Role of mixed liquor on NH4+–N removal via nitrification in IA-MBSBR.
► Effect of carrier concentration in nitrogen removal.