COMPARISON BETWEEN A CONVENTIONAL MEMBRANE BIOREACTOR (C-MBR) AND A BIOFILM MEMBRANE BIOREACTOR (BF-MBR) FOR DOMESTIC WASTEWATER TREATMENT

In this paper, the influence of biofilm carriers in a MBR on the performance of organic matter and nitrogen removal and the influence on membrane fouling were evaluated. The configurations studied included a Conventional Membrane Bioreactor (C-MBR) and a Biofilm Membrane Bioreactor (BF-MBR) operated in parallel, both fed with domestic wastewater. Regarding organic matter removal, no statistically significant differences were observed between C-MBR and BF-MBR, producing an effluent with a Soluble COD concentration of 27 +/- 9.0 mgO(2)/L and 26 +/- 1.0 mgO(2)/L and BOD concentration of 6.0 +/- 2.5 mgO(2)/L and 6.2 +/- 2.1 mgO(2)/L, respectively. On the other hand, the BF-MBR produced a permeate with lower ammonia and total nitrogen concentrations, which resulted in a removal efficiency of 98% and 73%, respectively. It was also observed that the fouling rate was about 35% higher in the C-MBR than that for the BF-MBR, which also presented a reduction of total membrane resistance, about 29%, and increased operational cycle length around 7 days, compared to C-MBR.