Removal of antibiotics in sponge membrane bioreactors treating hospital wastewater: Comparison between hollow fiber and flat sheet membrane systems

•Total nitrogen removal rate achieved 0.011-0.020 mg TN mg VSS−1 d−1 for both MBRs.•A higher removal of antibiotics was found in FS than in HF.•Remarkable removal of antibiotics (CIP, NOR, OFL, TET, TRI, ERY) were achieved.•Sulfamethoxazole was not significantly removed in Sponge MBRs.•A significant reduction of membrane fouling was performed in HF-Sponge MBR.

Hollow fiber (HF) and flat sheet (FS) Sponge MBRs were operated at 10-20 LMH flux treating hospital wastewater. Simultaneous nitrification denitrification (SND) occurred considerably with TN removal rate of 0.011-0.020 mg TN mg VSS−1 d−1. Furthermore, there was a remarkable removal of antibiotics in both Sponge MBRs, namely Norfloxacin (93-99% (FS); 62-86% (HF)), Ofloxacin (73-93% (FS); 68-93% (HF)), Ciprofloxacin (76-93% (FS); 54-70% (HF)), Tetracycline (approximately 100% for both FS and HF) and Trimethoprim (60-97% (FS); 47-93% (HF). Whereas there was a quite high removal efficiency of Erythromycin in Sponge MBRs, with 67-78% (FS) and 22-48% (HF). Moreover, a slightly higher removal of antibiotics in FS than in HF achieved, with the removal rate being of 0.67-32.40 and 0.44-30.42 µg mg VSS−1 d−1, respectively. In addition, a significant reduction of membrane fouling of 2-50 times was achieved in HF-Sponge MBR for the flux range.