Comparative study of suspended and attached growth in membrane bioreactors for wastewater treatment

Abstract The performance of laboratory scale experiments in treating synthetic domestic wastewater were conducted with suspended growth (SG) (without media) and attached growth (AG) (with moving media) membrane bioreactors (MBRs). The aim of this study is to compare fouling and the treatment performance of attached growth membrane bioreactor (AGMBR) with suspended growth membrane bioreactor (SGMBR) by assessing the removal of chemical oxygen demand (COD), nitrate, nitrite and ammonia. The finding shows that with 10% of attached growth media, average COD, nitrate, nitrite and nitrogen ammonia removal efficiency for AGMBR were found to be greater than the SGMBR system. AGMBR significantly increased critical flux, ( J c ) up to 48 L m −2 h −1 , hence producing low final transmembrane pressure (TMP) after cleaning and decreased the total resistance at 5.69 × 10 11 m −1 . Addition of cylindrical polythene media resulted in slow TMP increment that prolonged filtration process. In conclusion, AGMBR gave a better treatment performance and could minimize the membrane fouling problem.