Carbon membrane-aerated biofilm reactor for synthetic wastewater treatment

A carbon membrane-aerated biofilm reactor (CMABR) was developed to treat synthetic wastewater. Such membrane exhibited a high degree of adhesion and good permeability. Continuous experiments showed that COD and NH4+-N removal efficiency were 90 +/- 2 and 92 +/- 4% at removal rates of 35.6 +/- 3.8 g COD/m(2) per day and 9.3 +/- 0.6 g NH4+-N/m(2) per day, respectively. After 108 days, effluent total nitrogen (TN) kept at 35 +/- 4 mg/L when influent NH4+-N increased to 144-164 mg/L and removal efficiency of TN reached 78 +/- 3%. Furthermore, Stoichiometric analysis revealed that 70-90% of oxygen supplied was consumed by nitrifier. Scanning electron microscopic (SEM) images and component analysis of penetrating fluid revealed that extracellular polymeric substance (EPS) adhered to pore and that alkaline washing was an effective method to remove them. The study demonstrated that carbon membrane could be used as effective gas-permeable membrane in MABR for wastewater treatment.