Fate and removal of Ciprofloxacin in an anaerobic membrane bioreactor (AnMBR).

This study examined the removal of varying concentrations of the antibiotic Ciprofloxacin (CIP) over the long-term (120 days) in an anaerobic membrane bioreactor (AnMBR). The results showed that 50-76% CIP was removed with 0.5-1.5 mg CIP/L in the feed, although at 4.7 mg/L its removal efficiency decreased to <20%. It was found that biological degradation was the main mechanism for removing CIP, while adsorption onto the sludge only contributed a small fraction, and an even smaller fraction was due to the waste sludge discharged. CIP was biodegraded to some degree in the AnMBR, with some intermediate compounds detected using LC-MS/MS and GC-MS. This work showed the effectiveness of an AnMBR in removing CIP at low concentrations of <1.5 mg/L, and hence may be an effective treatment for removing other antibiotics from wastewater.