Simultaneous removal of organic matter and nitrogen compounds by combining a membrane bioreactor and a membrane biofilm reactor

Hydrogen-based membrane biofilm reactors (MBfR) have been applied to the denitrification of nitrate-containing water and wastewater. Adding an aerobic membrane bioreactor (MBR) to a MBfR provides significant nitrification and organic oxidation because most wastewater also contains a significant concentration of organic material and ammonium nitrogen. This study describes experiments that investigate the removal of organic and nitrogenous compounds in the combined MBR/MBfR system. The experiments demonstrate that the MBR/MBfR combination successfully performs COD oxidation and nitrogen removal for organic and ammonium loads in the ranges of 1000–4300 g COD/m3-d and 200–230 g N/m3-d, respectively. Total-nitrogen removal was controlled by nitrification in the MBR, because the MBfR denitrified all of the NO3- provided by the MBR. The nitrate flux in the MBfR was in the range of 4–8 g N/m2-d for cases of almost complete denitrification (>99 %); the H2 flux was varied from 1.4 to 2.8 g H2/m2-d.